TORPEDOES IN OUR WAR.
The electric torpedo system originated in America, so says Captain Davidson, formerly of the Confederate Navy.
After frequently referring to torpedo operations, in his “Naval History of the Civil War,” in varying terms of censure or of praise, Admiral Porter finally disposed of the whole question as to the efficiency and propriety of that method of warfare in the most complimentary terms of approval. But nowhere did he make the important distinction that there were two defensive methods or systems practiced during the war—the one electric, especially designed and perfected in every detail, and completely under the control of those operating it; the other a system (if it can be so called) of guerrilla torpedo warfare, which succeeded in destroying many vessels in the West, but closed all channels to friend as well as foe, and was too unreliable to be adopted as a regular service.
The distinction is important, and it is a matter of historical interest to know that the electric system of torpedo defense, now adopted by nearly every maritime nation, originated in the States during our war, and that the guerrilla method is never taken into consideration as a means of warfare, although it may be again resorted to in exceptional cases.
Admiral Porter states, in effect, in the work just referred to, that the floating torpedo which destroyed the Cairo was fired by a galvanic battery on the 12th of December, 1862. In this I am quite sure he is mistaken. No report was ever made to the government at Richmond of the successful use of electric torpedoes during the war, previous to my destruction of the Commodore Jones in May, 1864. Persons were, doubtless, experimenting with galvanic batteries in the West, but the torpedoes used against Admiral Porter’ fleet were known as contact torpedoes, of which there were many different kinds, and great ingenuity, mechanical skill, and self-sacrifice were shown in their design and application.
The importance of knowing exactly when and where electric torpedo defense was first proved to be a success in the war is generally admitted. Many have written upon this subject since the war. but from want of full information have made great confusion, and somewhat deprived our countrymen of the credit due in the matter, for I have frequently heard abroad that the practice originated with Russia.
Most persons interested in navy and army matters are more or less acquainted with the history of electric torpedoes; that is, of the many attempts made in the last and this century to use them successfully in war; and that every attempt met with failure until the Civil War in the States. With the reasons for those failures I am not now concerned, but I desire to draw attention to the impression upon the public mind which those failures made: an impression not only of indifference, but rather of contempt for that means of warfare; so that the reader of history may understand that the great difficulty the officers of the South had to contend with in their efforts to make electric torpedoes successful did not lie so much in devising or designing new, untried methods, as in the treatment, or rather discouragement, they met with from friend and foe for giving their time and expending the resources of the country for such a service by the one, or the “uncivilized” character of the means by the other.
In the fall of 1862 I received confidential instructions from the Secretary of the Confederate Navy to organize a torpedo department for defense and offense—under his direct authority—to form a corps of officers and men, purchase material, supplies, etc., and proceed to make experiments so as to get into active service as soon as possible.
All know how limited were the resources of the South, especially in such skilled labor and extraordinary material as a torpedo service required. However, by the spring of 1863 I had fully complied with the orders of the Secretary, and the Electrical Torpedo Department, as organized and commanded by me, was the only one of the kind under the authority of the Confederate Government, and during the latter part of the war it was extended to include the whole South.
It was a complete organization in every essential part, having a body of officers and men carefully selected for their character and intelligence, with relative rank and duties assigned them.
The mines and their attachments were carefully designed and made at the Tredegar Works at Richmond, according to detailed drawings and specifications furnished by me. Expensive and laborious experiments were made to determine the effect of gunpowder at different depths of water. The galvanic batteries were designed so as to be efficient, portable and quickly brought into service, to accomplish which was the greatest practical difficulty met with, for, when I took charge, the means of explosion known to us then were entirely too crude and clumsy to be of practical use. The insulated wire had to be procured from the North or from Europe, at great trouble and expense, through the blockade. Storehouses were built at suitable places for torpedo supplies, and a store vessel was anchored in the James river, with provisions and clothing, in charge of a paymaster. Finally, the torpedo stations were connected by telegraph with the office of the Secretary of the Navy, Mr. S. R. Mallory, formerly Senator from Florida.
If I am not carried away by what I deem to be the importance of this organization, I may assert that its success (as nail be seen further on) marks as distinct a period in history as the battle of the Merrimac and Monitor, or the employment of rifled ordnance.
The result of the organization, as just described, was the complete destruction of the gunboat Commodore Jones in the James river, May, 1864, by a torpedo mine made at the Tredegar Works, containing 1,800 pounds of sporting powder, placed in six fathoms of water and fired under my immediate direction. The destruction was effected at midday, and when the gunboat was accompanied by a powerful fleet under Admiral S. P. Lee. The fleet had on board a late servant of mine—a negro boy—who warned the officers that they were on dangerous ground. I was aware that the negro had deserted in the direction of the fleet, and for that reason had wires leading to the batteries on both sides of the river, believing that if the fleet cut the wires on the high left bank they would be content with that and proceed, not supposing that there was a battery with mines on the other side also, which was a swamp.
My surmise was somewhat correct, for, had the battery station on the left bank been occupied, we should have been discovered, as at one time the Commodore Jones was high enough up stream to have seen into the station; she could have been destroyed moments sooner, but we were waiting for an ironclad. The orders given on board were distinctly heard by us, and it was in consequence of certain orders that the Commodore Jones was destroyed as she dropped back and over the mine.
The fleet very soon after (the same afternoon) retreated down stream, and did not return so high up the river again for more than a week, the importance of which will be seen further on. Many valuable articles from the wreck were picked up, especially official correspondence of importance to the Confederate government. The Captain’s trunk, private correspondence, Bible, etc., were carefully packed up and sent at once to Major Mulford, of the United States flag-of-truce steamer.
The simple act of destroying the Commodore Jones was not in itself of so much importance as the destruction by torpedoes of many other vessels—ironclads, for example; but aside from its marking the first success of an electric system of torpedoes, it had another bearing.
On May 5, 1864, General Butler landed at Bermuda Hundred, guarded by the same fleet, under Admiral Lee, to which the Commodore Jones was attached. Admiral Lee lost no time in pushing on up the river with his whole fleet, for in a few days thereafter he was off Four Mile creek, where he witnessed the destruction of the Commodore Jones. On the 16th of the same month General Butler made his attack at the rear of Drury’s Bluff, James river, and was repulsed by General Beauregard. That struggle was one of the hardest of the war. The trees and ground in front of the works were a sight to behold. There was many a moment when the result was doubtful.
Now, the object of pushing Admiral Lee’s fleet, accompanied by transports, up the river at that time was believed in Richmond to be the assistance of General Butler in the attack on Drury’s Bluff. Certain it is that there was nothing to prevent Admiral Lee from doing so but the torpedo defenses, and these, as already shown, compelled his retreat for the time. (Chapin’s Bluff batteries were just below Drury's Bluff, but they would not have prevented the monitors from attacking both bluffs.) This was, of course, known at Drury’s Bluff, and enabled several hundred of our best gunners to leave the batteries in front and serve the guns in the rear works against Butler.
If Admiral Lee could have sent a few ironclads to within sight of the Bluffs, the gunners stationed at the river batteries would have been retained here. Without them at the rear, General Butler could not have been repulsed, and Drury’s Bluff, the key to Richmond, would have fallen that 16th of May, 1864.
Mr. Mallory, the Secretary of the Navy, in writing me after the war, uses these words: “The destruction of the Commodore Jones, the
leading vessel of Admiral Lee’s fleet, which was ascending the James river to co-operate with General Butler in the attack on Drury’s Bluff, by causing the retirement of that fleet, undoubtedly saved Drury’s Bluff, the key of Richmond.” And in the same letter he adds: “I always regarded the submarine department under your command as equal in importance to any division of the army.”
Admiral Porter states that the man who fired the torpedo that destroyed the Commodore Jones was shot from one of Admiral Lee’s boats. This is a mistake. He was still living in 1889. The man shot was a carpenter of no torpedo importance. He also says that the men captured were “very communicative.” I am sure Admiral Lee thought they were, and that was just what I wanted. They were as good and true men as ever stepped in shoe leather, and had often been well drilled as to how much and what to say, in case of capture, for we were always much exposed. Had they been untrue, the fleet could have captured me, and also destroyed the backbone of the James river, the torpedo defenses, that same afternoon, and gone on up to the assistance of Butler at Drury’s Bluff and, I believe, to the capture of Richmond.
I have often thought there was as much to be accomplished in working upon the credulity of the opposing force in time of war as in the use of your weapons, and that a special department might reasonably' be organized for that purpose. This suggested itself to me during our war, because my torpedo department could not then be assisted by gun batteries at the several torpedo stations, and I was forced to all sorts of stratagems in order to work the defenses without such assistance. Think what might have been done with a highly nervous man like General Bragg, or even Sherman, for that matter, he himself having said, as we read: “The difference between Grant and me is, Grant don’t care a d—n what the enemy is doing, and it just runs me crazy.”
The personnel of war is not made up of Lees or Grants, but of comparatively very inferior substances, and the larger number of high officers could be easily thrown off their guard and made to vacillate, delay, and sacrifice their opportunities by annoying devices, plans, demonstrations, etc., well arranged and put forward by some such genius as would make a first-class detective, for instance. Of course, both sides could play at the same game: but as in the case of the torpedoes, the side that did not use it would be under a disadvantage.
A narrow escape was made by General Foster, General Negley, Lieutenant-Commander Cushing, and others when making a reconnoissance up the James river (I think in August, 1863), accompanied by the Monitor and another vessel. The Commodore Barney was ahead, and just above Atkin’s Landing, when an electric torpedo of 1,800 pounds powder in five fathoms of water was prematurely exploded under her bows; but her headway took her under the falling mass of mud and water, and many men and much material were washed ashore. The Northern papers stated there were thirty-six men killed and wounded. The officer in charge of the torpedo station had the “buck fever,” and fired the torpedo from sheer nervousness, and when I arrived at the station, half naked, from a bed of illness, be could hardly speak.
That was the lowest station on the river at that time. I was almost always near by, but on that day I was ill in bed with bilious fever, and rode to the station en déshabille, hoping to arrive in time. It was Cushing’s sudden dash up the river that saved the situation. I should certainly have let the Commodore Barney pass on up and waited for the Monitor, knowing that at least the Barney could have been destroyed on her return. It is very singular that this occurrence did not give sufficient warning to Admiral Lee to enable him to avoid the destruction of the Commodore Jones, and carry out the object of his expedition in May, 1864, when co-operating with General Butler in the attack on Drury’s Bluff on the same river.
The failure to destroy the Barney made a most unfavorable impression at Richmond, and increased the howl of my opponents against the service I was engaged in, but I was always firmly supported by Mr. Mallory, who had the greatest confidence in the success of that means of warfare, and by our mutual friend. Captain John M. Brooke, who, later on, became Chief of Ordnance, and then the Torpedo Department feared no enemy in the rear.
In Admiral Porter’s remarks as to the attack on the Minnesota, he says that “no serious damage had been done.” and “the torpedo, which weighed fifty pounds, was not placed in contact with the ship, but was prematurely exploded.” These statements are incorrect. There was a board of inspection ordered on the ship, and it reported much damage— certainly enough to justify the assertion that the torpedo was not “prematurely exploded,” if we have no other evidence; but the contact was as well made as it is possible with any ramming torpedo known, even at the present time.
The report of the inspecting board, or of the commander of the ship, I forget which, showed that the torpedo exploded just abreast of a mass of shot and shell that the Minnesota had lately taken in to carry South. Moreover, the torpedo was too small—I thought so at the time. I could not get a larger steamer suitable for the purpose, and the one I used would not manoeuvre with a larger torpedo down in an ordinary sea-way in such open waters as the mouth of the James river.
The attack, however, may fairly be called a successful one. It was the only attack of the kind during the war where any success was met with without the loss of the attacking party, and consequently the only one to prove the efficiency of the method. It must be considered that I had to explode my torpedo against perpendicular sides, whereas Lieutenant Cushing was lucky enough to find a vessel having an “overhang” (the Albemarle) under which he could not help getting his torpedo. He didn’t require a contact with the sides.
As to being drawn into the hole in case I made one in the side of the Minnesota (as was the case with the David that sank with the Housatonic), I had provided for that by previous practice by direct ramming at an angle, always stopping the engine before striking, and practicing the engineer to go full speed astern as soon as he felt the blow, without waiting for orders. My torpedo struck the side of the Minnesota and exploded in just about one second after contact—an excellent result for the fuse of that day. The pole was shattered to pieces and the little steamer driven back forcibly.
When she backed off about fifty yards, and stopped to reverse and go ahead, her single cylinder engine caught “on the center,” and there we remained—it seemed to me about forty years—under the fire of the Minnesota. The engineer, Mr. Wright (one of the bravest and coolest men I ever knew), got the engine free again, having to feel for the different parts in the dark. The little steamer was peppered all over with bullets. Several passed through my clothes, but we got off without any injury whatever. I then steered in the direction of Norfolk to throw pursuers off the scent, which proved successful. There was a steamer under the stern of the Minnesota that ought to have caught us easily. Several men were seen on her deck, forward, and those were fired at rapidly to prevent their casting off their line, and she did not leave the Minnesota while in sight.
I believe there are those still living who, during the Civil War, regarded torpedo warfare as unworthy the higher qualities and duties of a naval officer. To such I would only ask: Whose judgment and foresight have proved the soundest? To those who believed it unfair and illegitimate I invite a careful study of all the circumstances attending the explosion of General Grant’s mine before Petersburg, as compared with those under which the Commodore Jones was destroyed. Before making up my mind during our war to devote all my energies to the development of torpedo warfare, I thought seriously of the humanitarian phase of the question, but it did not take long to come to the conclusion that what we call humanity in war commenced after the surrender, excepting for the disabled, of course. Grant didn’t think much of humanity when he used the mine at Petersburg, nor when he refused to exchange prisoners, knowing that the South was wholly unable to feed even his captured men; and to-day I believe that the more destructive weapons employed in wars, the less apt are wars to occur, and the soonest over. Long wars spread desolation and darken the earth. It would be far better to blow a whole army up in one mine and a fleet with another than that a war should last four years.
HUNTER DAVIDSON.
The Highflyer, a protected steel cruiser of the second class, was launched on Saturday, the 4th inst., from the yard of the Fairfield Shipbuilding and Engineering Company, Limited, Govan. The vessel is a sister ship to the Hermes, launched by the same builders on April 7, and illustrated and described on pages 470 and 497 ante. The two cruisers represent an improvement on the Juno class, of which the Fairfield Company built two—the Venus and the Diana. The dimensions of the Highflyer are: Length between perpendiculars, 350 ft.; breadth extreme, 54 ft.; displacement, 5,600 tons. The coal capacity is normally 550 tons, but provision has been made for carrying a greater quantity if necessary. The propelling machinery will consist of two sets of triple-expansion engines fitted in separate engine-rooms, each set having four inverted cylinders and four cranks. Belleville boilers will be fitted by the builders, and it is expected that the vessel will attain a speed of 20 knots.—Engineering.
The Angler, torpedo-boat destroyer, left Chatham Dockyard on the 3rd inst., for the final trials of her machinery, and the results obtained were satisfactory. The mean speed obtained for six runs on the measured mile was 30.559 knots. The official results were as follow for the three hours’ full-speed trial: Draught of water, forward 5 ft. 11½ in., aft, 7 ft.; mean speed of ship, 30.372 knots; steam pressure in boilers, 212 lb. per square inch; revolutions per minute, 399.4 starboard, 398.3 port; mean indicated horse-power, 2,910 starboard, 2,910 port—total for the two sets, 5,820. The steering circle, stopping, and starting trials were also successfully carried out. The builders were Messrs. J. I. Thornycroft and Co.—Engineering.
REPORT OF TRIAL OF MARSDEN’S CORN-PITH CELLULOSE.
H. M. S. Nettle, Portsmouth.
Carried out on 18th January, 1898.
COFFERDAM.
The cofferdam was built of 15-lb. steel plating. 6 feet 6 inches high and wide, by 3 feet 3 inches deep. Its general scantlings are shown in the appended tracing. It was divided into three compartments by two transverse bulkheads. All rivet work was water-tight and the structure was well built. The middle compartment contained 67.58 cubic feet, the side compartments 35.52 cubic feet each.
THE CELLULOSE.
The cellulose was received at Portsmouth Dockyard on January 8, and was kept stored until the day of packing in the cofferdam, January 12. Its condition on opening the boxes was dry and excellent.
PACKING.
The middle compartment of the cofferdam was packed with 495 lbs. of cellulose in briquettes, at a density of 7.3 lbs. per cubic foot. The right-hand compartment was packed with 260 lbs. of cellulose, also in briquettes, at a density of 7.3 lbs. per cubic foot. The left-hand compartment was filled with 190 lbs. of cellulose, in the loose or natural condition, and condensed to a density of 5.35 lbs. per cubic foot. A plate cover with water-tight joints was then bolted on, and the cofferdam was set on board the Nettle for ballistic and obturation tests.
THE FIRING TRIAL.
The gun used was a 5-inch B. L. R., with the muzzle thirty feet from the face of the cofferdam. The projectile was a service common shell, weighing 50 pounds, with about 3½ lbs. bursting charge and nose percussion fuse. The striking velocity was about 1,200 feet per second. The shell struck the cofferdam on the central line two feet from the bottom and burst in the dam just as its joint entered the back plate. The explosion was very violent and blew out the entire back of the compartment, carrying with it about one-third of the cellulose in the rear of the cofferdam, but leaving the forward two-thirds standing quite firmly in place (as shown on the tracings). The rents in the plating extended into the side compartments, but the cellulose therein was not disturbed. The cellulose blown out was scattered all over the deck, but although the shell exploded inside the dam, none of the cellulose was set on fire or even charred. As soon as the photographs were taken, a box-shaped front of steel plating was bolted on the face of the cofferdam and a stand-pipe about three feet long was fitted on its top. An ordinary firehose was connected to a pump, and the front filled with water. The water at once rose to the level of the shot holes, but the cellulose began to expand and no water appeared at the back. The tank was filled to the top of the stand-pipe, but still the back of the cellulose, even under this pressure of a head of 7 feet 6 inches, was not even damp. Finally, after seventeen minutes from the time the water was put on, a hole about eight inches in diameter was washed out directly in line with the shot-hole. The rest of the material still remained firmly in a ring or arch around this opening. Experiments were then discontinued and the cofferdam slewed around with handspikes to get another photograph. Even this shaking did not dislodge the arches of briquettes.
This completed the firing trials. It is interesting to note that a head of water three feet above the head of the cofferdam (the height of which was 6 feet 4 inches) gives a mean head of 6 feet 2 inches on the cellulose. As the total exposed area of the compartment was 20.8 square feet, the total pressure withstood by the unsupported cellulose was about 3 lbs. by 144 by 20.8, 8,985 lbs., which is four tons. When it is considered that this weight was borne for four minutes solely by the expansive power of the cellulose, against the walls of the dam, the result appears most remarkable and highly satisfactory in every way.
THE BOILERS AND BULKHEAD DOORS OF THE CHICAGO.
The unarmored cruiser Chicago of the United States navy was one of the original vessels of the famous “White Squadron.” She was launched in 1884, and on her trial trip she made 15 knots with 5.083 horse-power. It was decided about three years ago to make many changes in the Chicago, and these changes, which are almost completed, will convert her into a fast cruiser of 18½ knots, developing about 9,000 indicated horse-power. New engines, of course, were required, and they were built at the Brooklyn Navy Yard, as well as the boilers shown in our engraving. The Bureau of Steam Engineering adopted a combination of the cylindrical Scotch boilers and the sectional type. The engine-room is next the Tour Scotch boilers, then comes the blower room, then the six Babcock & Wilcox boilers. The Chicago will be worked under forced draught on the closed stokehold system when running at high speed. Our engraving shows a pair of the Scotch boilers, which are about 1,000 horse-power each. They are placed athwartships, and our illustration supposes the visitor to be in the stokehold looking at one pair of boilers, while the other pair is at his back. The Scotch boilers all make use of a common stack, and at the level of the protective deck the stack is crossed by heavy armor bars which preserve the integrity of the protective deck.
The Scotch boilers were built at the Brooklyn Navy Yard and are made of nickel steel, the sheets being 1 5/16 inches thick and the heads 7/8 inch thick. The mean diameter is 13 feet 8½ inches and the length 10½ feet. The three corrugated furnaces are 3 feet 5 inches in diameter and are all fired from the same stokehold. The length of the grate is 6 feet 8 inches. The outside measurement of the 417 tubes is 2inches, and they are of a thickness of No. 10 Birmingham wire gage. The heating surface of the tubes is 1,770 square feet; the heating surface of the furnace is 134 square feet; the heating surface of the combustion chamber 166 square feet, and of the tube sheets 66 square feet. The total heating surface is 2,138 2/3 square feet. The grate surface is 68.33 square feet. The boilers are covered with magnesia covering. It is expected that the Scotch boilers will drive the ship at a speed of 13 nautical miles an hour, and with the water-tube boilers it is expected that 18½ nautical miles an hour will be made. The six Babcock & Wilcox boilers have a total heating surface of 18,000 square feet and 360 square feet of grate surface, making the total heating surfaces foot up 26,550 square feet and the grate surfaces 633 square feet. The bunker capacity is 920 tons. The steam pressure is 180 pounds per square inch.
The twin-screw engines are of the horizontal triple expansion type. The cylinders are 33½ inches, 50½ inches and 76 inches, the stroke is 40 inches and the engines make 120 revolutions per minute.
We now come to another interesting feature of the reconstructed vessels—the bulkhead doors. Lord Charles Beresford says: “It is a fact that upon the loyalty of the water-tight doors, when closed, and upon the assurance that they are properly closed, depends the power of a battleship to float when wounded by ram, torpedo or a gun. It has been authoritatively stated that the cause of the loss of the Victoria was that the water-tight doors were not closed, and it has been constantly proved to be impossible to close water-tight doors in an emergency, no matter how well disciplined and how gallant the ship’s company may be. The system of closing the doors by evolution as to time invites an accident.” Some very able experts contend that there should be no doors at all, and that the main bulkhead should be intact to the main deck.
To the layman, the number of bulkheads, doors, hatches and valves is extraordinary. Take the battleships Indiana, Massachusetts, or Oregon, for instance; they have 272 water-tight compartments, and the total number of water-tight doors and hatches is 354. The number of valves for ventilating, draining and flooding hulls, including sea-valves and pump-suctions, and excluding all valves for motive power and auxiliaries, numbers 294, making a grand total of water-tight doors, hatches and valves of 648. Valves are less important than doors and hatches, but when they guard a sluiceway, the passage of a ventilating pipe from one compartment to another, or a magazine flood-cock, they involve the integrity of the ship in an emergency. It is hardly possible to exaggerate the sudden turmoil and shock of a collision in a sea-way, accompanied by fog and blackness, perhaps within as well as without the ship, the wild upheaval and stampede of being torpedoed, or the strain and jar of modern battle; and it requires about no men, excluding officers, to bring the cellular structure of the ship into operation when needed in the type of ship to which we have referred, so there is no wonder that ships go down when they have their skin punctured below the waterline, as for instance the Vanguard, Victoria, Blanco Encalada. and Elbe.
Many experiments have been tried and systems introduced for the instantaneous closing of all the bulkhead doors in an emergency. We present some engravings of one of the most successful solutions of this problem—the “long arm system” of Mr. W. B. Cowles, of the Construction Department of the United States Navy. The cruiser Chicago as reconstructed is provided with an installation of this system. Mr. Cowles considered that a practically perfect system would be to tie together in assorted bunches the widely-distributed devices in a ship, by bringing the connecting strings from each device to a switch-board for each bunch and then assemble the switch-boards into one or more central stations, from which each device can be controlled by an operator, independently, and to arrange the devices as they are needed to be operated in case of an emergency, so that this can be done with precision and full knowledge, from a point where the emergency can first be discovered. Arrangements should also be provided so that neither the emergency operation nor any other can harm the attendant or take control out of his hands, and all water-tight doors should be given an equal rank and precedence with the bulkhead of which when closed they form an integral part. The water-tight doors should be capable of closing under head or rush of water, and every bunker door should be able to close through coal. A system of this kind, placing its sole manipulation in the hands of one man, is comparable to the switch and signal tower of a railway.
There are two general schemes in the Cowles long arm system—the double line and the single line. The double line is more complicated and efficient, involving an operator at the central station. The single line answers in many cases where control valves and telltales are not required at the central station. Our illustration shows the single line system as applied on the United States cruiser Chicago.
[IMAGE: Bunker door with clear way open four inches.]
The installation consists of eleven vertical sliding doors, all in the engine and boiler compartments, made of ¼-inch steel plates with vertical angle iron stiffeners and with manganese bronze plowshares to force its way through coal. The power cylinders for each door are made of seamless brass tubes. The system is operated by a steam accumulator and duplex pump of the Worthington type. They are placed under the protective deck. The hydraulic main is 2 inches in diameter, reduced in suitable steps. The emergency gear consists of a power cylinder with a 4-inch stroke, operating the by-pass cock on the accumulator and a corresponding telltale and controlling valve in the conning tower, connected by a 1/8-inch pipe and forming a “primary circuit.” This circuit consists of two cylinders with their pistons and piston-rods connected by a double line of small piping. One cylinder, called the power cylinder, is connected with the device to be operated; the other cylinder, called the “telltale,” is placed at the point where it is intended to operate the device. These two cylinders may be at any distance apart.
The double line of piping is so arranged that the pistons in the cylinders operate in exact accord. The power cylinder does the desired work, while the telltale cylinder reveals the position of the lower cylinder and consequently that of the bulkhead door. At each door is a so-called “liberty valve,” which can be started independently of the general system. Ingenious devices are provided to tighten the doors at side and bottom. One of our engravings shows the door under a head of water, with the tightening gear slacked up, and another, a bunker door, with all the tighteners in operation.
[IMAGE: Bunker door under a head of water just before opening.]
The side tighteners consist of traveling rollers held between a wedge track and a wedge bar, each of these latter being the full length of the door. The wedge track is secured permanently to the door, and the wedge bar rides with the door throughout its travel, except during the short tightening interval at the closing end of the stroke, within which the wedge bar is held stationary on the guide, thus causing relative movement between the wedge track and wedge bar on the rollers. This movement presses the wedge bar out against the guide lip, and the wedge track, with the door and seating strip, in against the seat.
[IMAGE: Bunker door under head of water, with tightening gear slacked up.]
The doors are of ¼-inch steel plate with 2¼-inch by 2¼-inch by 3/8-inch vertical steel angle stiffeners at side and with manganese bronze plowshare and top tightener castings stiffening, respectively, the bottom and top edges of the plate; the seating strips at top and bottom are of steel 3/8 inch thick; the side seating strips, wedge tracks and wedge bars are of naval brass with Tobin bronze rollers 1½ inch diameter by 1½ inch long. The interlocking toes, pins and rollers are of steel, with adjustable manganese bronze stop-plates and fish-plate brackets. The wedges set in the plowshare are of steel, removable, and all parts of the door are screwed together throughout in such a manner that corrosion cannot affect the screws and so that any part may be renewed without injuring any other part. It should be noticed that the side edges of the door, outside of the stiffening angle, are flexible. When the tightening gear is free the door has 1/8 inch play in its guides, both side-tips of toes are easily ground and pressed down, and fall to the floor between the webs and seat.
ADDITIONS TO THE NAVY IN 1897.
The year now closing has been one of considerable activity in naval work, and although the tonnage and power of vessels actually floated falls short of that of some preceding years, the cause is easily explained, and is temporary. The engineering dispute has delayed the work in private yards, and also in the dockyards—two more battleships would have been floated had the stern frame and stem, etc., been machined and delivered in time, the under-water fittings completed, and the propeller-shaft tubes bored. But while the tonnage floated is not so great as in some previous years, there has been continued recognition of the need for sea power, and thus the Admiralty have been liberal with their orders and assiduous in seeing that the work is expeditiously done. We have already recorded the expansion of the original navy programme for the year; all the vessels have been ordered except four armored cruisers, which will probably be given out early in the year. Meanwhile we content ourselves with a consideration of the warships built and tried during the year.
There have been 45 warships constructed in 1897 for British and foreign powers, and these in fighting trim represent a value of 6,617,700l.; while in the previous year the total value was 10¾ million pounds. This decrease is largely due to only one battleship being floated, whereas in last year’s total there were included six of great size, four for Britain and two for Japan. Thus the tonnage in 1897 was only 96,786, against 155,849 tons in 1896; and even the latter was not a record, as the total in 1892 was 161,596 tons, although the average for the first six years of the decade is not over 100,000. The collective horse-power of propelling machinery for all warships, however, does not show the same falling off, aggregating 331,050 indicated horse-power, against 377,981 indicated horse-power, due to the inclusion of a large number of torpedo-boat destroyers. As in the past year, one-third of the tonnage completed was for foreign governments, principally Spain, Japan, China, and the South American republics. The totals just given are accounted for as follows:
— | Number. | Tons. | I. H. P. | Value of Ships Completed. |
Dockyard | 4 | 31,885 | 47,000 | 1,752,700 |
Private yards (H. M. S.) | 22 | 34,111 | 163,400 | 2,385,000 |
" " (foreign) | 19 | 30,790 | 120,650 | 2,480,000 |
| 45 | 96,786 | 331,050 | 6,617,700 |
In the previous year the foreign tonnage was 47,364; the horse-power, 118,364 indicated; and the value, when completed, 3,059,000l.; so that there has only been a decrease in tonnage. This is explained when it is recalled that instead of battleships costing 65l. per ton, a greater number of destroyers of 200/. per ton are included in the list.
The work of the Royal Dockyards does not bulk so largely as it might have done: two battleships are almost ready for launching. These, if they had not been delayed by the strike, would have brought the total quite up to the average, which for the preceding seven years was about 50,000 tons, against 31,185 tons for this year; while the average output for the navy from private yards is about 39,000 tons, against 34,111 tons for this year. But when it is recalled that the Royal Dockyards are so largely for repair, and especially for recuperative work in war times, the output has not the same significance; the interesting point is that there are in process of construction, including all vessels ordered and not yet tried, warships aggregating 355,620 tons and 766,800 indicated horse-power; at the end of last year there were completing, and under construction, vessels of 284,660 tons and 625,500 indicated horse-power, so that apparently there is more work now; but the rapidity of construction at the Royal as well as private dockyards will soon make a material reduction in these totals. The problems of design involved in this great fleet can only be guessed at; but the mere figures themselves suggest the work undertaken by Sir W. H. White, K. C. B., the Director of Naval Construction, and by Sir John Durston, K. C. B., the Engineer- in-Chief. Of the vessels building, 20, of 145,295 tons, with engines of 218,000 indicated horse-power, are in course of construction at the Royal Dockyards, where some 22,000 or 23,000 men are employed. The difficulties of management are great, at a time when labor is more or less in open revolt throughout the country; and the fact that there has been no real indication of cessation of work is due to the efforts of the Director of Dockyards, Mr. James Williamson. We give in the appended table the number and tonnage of the ships built for the navy in each year of the current decade:
Production of British Navy Ships, 1890-97.
Year. | Dockyard. | Private Yard. | Total. | ||||
No. | Tons. | No. | Tons. | No. | Tons. | ||
| |||||||
1890 | 8 | 22,520 | 13 | 42,475 | 21 | 64,995 | |
1891 | 8 | 68,100 | 10 | 39,150 | 18 | 107,250 | |
1892 | 9 | 50,450 | 13 | 90,730 | 22 | 141,200 | |
1893 | 9 | 32,400 | 5 | 1,910 | 14 | 34,310 | |
1894 | 8 | 26,700 | 19 | 4,825 | 27 | 31,525 | |
1895 | 8 | 70,350 | 28 | 66,412 | 36 | 136,762 | |
1896 | 9 | 71,970 31,885 | 26 | 36,515 | 35 | 108,485 | |
1897 | 4 | 22 | 34,111 | 26 | 65,996 | ||
Total. | 63 | 374.375 | 136 | 316,148 | 199 | 690,523 |
The vessels built for the British navy have already been described in Engineering, and here it is only necessary to mention them. Front the Portsmouth yard there was launched the Canopus,[1] an improved type of Renown, differing only from the Magnificent class in having Belleville boilers and a slightly thinner although specially hardened armor, which so reduce the displacement as to enable the vessel to pass through the Suez Canal and steam into some of the harbors in the East with limited depth of water. The Canopus is 390 ft. in length, of 74 ft. beam, and at 26 ft. draught displaces 12,950 tons. Her engines, being built by Messrs. Scott, of Greenock, are to develop 13,500 indicated horsepower with natural draught, giving a speed of 18¼ knots. She has the same armament as our best ships. The Andromeda, the next ship in point of size launched from the Dockyards, is a cruiser of 11.000 tons, built at Pembroke, and belonging to the Diadem or Niobe class.[2] Her engines of 16,500 indicated horse-power are by Messrs. Hawthorn, Leslie and Co. The first of the class, the Diadem, will proceed on her steam trials in January, and much interest is attached to them, as the Belleville boilers are fitted with economizers in the up-take. The feed passes through the pipes of the economizers before entering the main tubes, and experiments with separate boilers give promise of a much higher efficiency than with the ordinary Belleville boiler. The Diadem is the first ship with these improved boilers to be submitted for trial. The Vindictive is a fleet cruiser especially strengthened for ramming, and armed for a long, stern chase.[3] She was built and engined at Chatham, and belongs to the same class as the Arrogant, the result of whose trials are recorded in our table. The fourth ship on the Dockyard list is the Pomone, launched at Sheerness, and fitted with engines by Messrs. Penn, of Greenwich. The prototype of the class was the Pelorus, described in Engineering, vol. lxiii, page 385. Devonport has not launched any vessel, but good progress has been made with the battleship Ocean. The output in tonnage from each of the five Royal yards is given below:
| 1896 | 1897 | Eight Years. | Average. | |||
| No. | Tons. | No. | Tons. | No. | Tons. | Tons. |
Pots-mouth | 3 | 26,300 | 1 | 12,950 | 13 | 121,635 | 15,204 |
Chatham | 1 | 14,900 | 1 | 5,800 | 12 | 100,350 | 12,541 |
Pembroke | 1 | 14,900 | 1 | 11,000 | 9 | 78,915 | 9,864 |
Devonport | 2 | 11,600 | — | — | 16 | 52,500 | 6,562 |
Sheerness | 2 | 4,270 | 1 | 2,135 | 13 | 20,995 | 2,624 |
It is scarcely necessary to enforce the point that a very large amount of the work of the Dockyards is in connection with the trials of new ships, and repairs and overhauls for re-commission, etc. The extensive fleet of the British navy involves a very heavy expenditure under this head: this year it has been greater than usual, owing to the Review, and to the fact that as new ships could not be completed in time to relieve the ships abroad, others had to be overhauled for the service. In this way several ships have been largely renewed, amongst the number being the Mercury, Porpoise, Arethusa, Mohawk, Leander, Barracouta, Swallow, Hotspur, Raleigh and several others.
[TABLE: OFFICIAL TRIALS OF BRITISH WAR SHIPS, JANUARY TO DECEMBER, 1897.]
The British ships built in the private yards do not call for special note. The Europa and Niobe built at Clydebank and Barrow, are of the same class as the Diadem already referred to; and the Pegasus and Pyramus built by Palmer, and the Perseus launched from the Earle Company’s yard at Hull, are of the Pelorus type. The other vessels on the list are mostly torpedo-boat destroyers—the Fairfield Company having launched the Gypsy, Fairy, and Osprey; Palmer’s Company, the Flying Fish, Fawn, and Flirt; Laird Brothers, the Panther, Seal, Wolf, and Express, the latter exceptional in being a 32-knot vessel, while all the others are 30-knot craft. From the Barrow works of Messrs. Vickers, Sons and Maxim there was also launched the Leopard; Messrs. Doxford launched the Violet and Sylvia; Messrs. Hawthorn, Leslie and Co., the Cheerful; while. Messrs. Thornycroft also added to the number, which further includes a few gunboats. But after all, the chief interest in these destroyers is the result of their speed trials, and we are able to give a list which shows the power, speed, and coal consumption of all the boats of the class which have passed through official trials this year. This table scarcely calls for comment; but it will be seen that for 30 knots the power has varied from 6,606 to 5,654 indicated horse-power; but as a rule, 6,200 is about the average. The best speed got was with the Fairfield boat, 30.674 knots. Messrs. Palmer have been very successful with these craft, although the coal consumption seems higher than with some of the others. There is in this respect remarkable variation. Perhaps it may be well to state that Laird Brothers adopt the Normand type of boiler, Thornycroft and Fairfield the Thornycroft type, and Palmer the Reed type. These have all been illustrated in Engineering. It may here be remarked that the Clydebank Company have, during the year, passed through their trials several Spanish boats.[4]
We also give in tabular form the official results of the trials of other ships. The first four ships and the last on the list are alike as regards design—they belong to the Magnificent class of battleship. The cylinder dimensions, too, are the same, so that the coal consumption may be fairly compared, although it may be that the variations in the draught of the ship vitiate any true comparison of the speeds realized for the powers given. All these ships, like so many of their predecessors, have easily attained on trial the results anticipated in their design. The Terrible was, as is now world-wide known, fitted with Belleville boilers, as is also the Arrogant. These two are the only vessels on the list fitted with water-tube generators.
As to the foreign vessels, Sir W. G. Armstrong, Whitworth, and Co. launched the cruiser O’Higgins, of 8,500 tons and 16,000 indicated horse-power, for Chili; the Hai-Tien, of 4,500 tons and 17,900 indicated horse-power, for China (see page 751 ante)-, the Takasago, of 4,160 tons and 14,750 indicated horse-power, all remarkably fast steamers; and the two Norwegian battleships, Harald Haarfarge and Tordenskjold, of 3,500 tons and 4,500 indicated horse-power (page 62 and 419 ante). The Clydebank Company launched four torpedo-boat destroyers for the Spanish government, the first of which was illustrated in the first number of this year. Messrs. Laird, of Birkenhead, completed a training-ship of 1,270 tons and 1,000 indicated horse-power, for the Argentine navy, and Messrs. Yarrow built several torpedo-boat craft, principally for South American republics.
[TABLE: OFFICIAL STEAM TRIALS DURING 1897 OF TORPEDO-BOAT DESTROYERS.]
HIGH EXPLOSIVES AND MODERN WAR-VESSELS.
The old battleship Resistance has at last come to the end of her somewhat chequered career, and her 4-inch iron plates have recently been stripped off for service as targets on the excellent ground at Whale Island. She has been riddled with ordinary projectiles of every calibre, torn to pieces between decks by high-explosive shells, and sunk by torpedoes on more than one occasion, having been subsequently raised for further experimental practice upon her hull. A vast number of points have been conclusively settled during the course of the experiments which have been made with her. The futility of ordinary light armor as a preventive to the penetration of the smallest armor-piercing projectiles, even when protected by a backing of several feet of teak or oak timber, has been plainly shown. The great destruction which would be effected upon the upper decks by the smashing of the superstructure and boats thereon in action, has also been illustrated by experiments with dummies; whilst the value of a thick stratum of coal in bunkers along the ship’s side has been thoroughly tested; and, lastly, the awful havoc which would be wrought between decks by the bursting of shells filled with high explosives, has been exhibited with appalling distinctness.
The first of these important lessons has resulted in the substitution of carburized armor plates for ordinary steel shields to protect all the heavy and medium gun positions in recent war vessels; the second, in the covering over of the upper deck battery at the sides with plating for some distance, and the stretching across the open space thus left between of a stout steel wire netting to catch splinters; and the third, in greatly multiplying the number and increasing the size of the coal bunkers along the ship’s sides, from the main deck down to the bilge. The fourth lesson, however, remains only as a terrible, incontrovertible fact, which cannot apparently be got over. It is to this fact that we allude now.
We would invite an inspection of the hull and between decks of the Resistance in order to emphasize the remarks which we are about to make. No very heavy gun has been employed in negotiating the destruction of the helpless hulk; but 9.2-inch projectiles have passed through her from side to side, just as though she was so much putty, and even 6-inch armor-piercing shot have traversed her from stem to stern; the wrought-iron armor plates being torn off, and the skin of the ship’s side and bulkheads being swept away as though they consisted of brown paper. Then the between decks is a sight never to be forgotten—framing, splinter screens, partitions, and bulkheads have been rent into fragments by the bursting of the high explosive shells, whilst grim splashes of a yellow substance that has marked the places where shells have bursted outside the plating betoken the character of the explosive employed.
It is now an acknowledged axiom that high explosives will be employed in shells. Whether naval officers object to carry them on board ship or not, they will in future be the principal ingredient by which shells are filled for coast and siege purposes; and already the nature of high explosives to be used as a service bursting charge for high-angle howitzers in coast and siege batteries has been practically determined.
After exhaustive trials, all inventions in this direction, except wet gun-cotton and lyddite, have been discarded. A satisfactory high explosive has been defined as fulfilling the following conditions: It should be safe in manufacture, store and transport, and stable under service conditions. It should be of a convenient form for filling shell, and safe to manipulate in the process. It must be capable of standing the shock of discharge in high velocity guns, and must, on striking, detonate with violence and certainty, and without the aid of any dangerous fulminate. The explosive should be capable of having its sensitiveness increased or diminished as occasion may require, and a shell, when filled with it, should not detonate when hit by another shell. Of those high explosives experimented with, the two coming nearest to the standard are wet gun-cotton, which has been adopted by at least one European power, and lyddite, which is used in our service. Wet guncotton will not detonate in a shell struck by another shell, and in this respect is more satisfactory than lyddite; but gun-cotton, to produce its best effect, must be compressed into discs to fit the interior of the shell, and the shell must therefore be made in two parts and screwed together—a source of weakness and possible danger. Dry cotton and a a fulminate are, moreover, required to detonate it. Hence lyddite, to which none of these objections apply, will probably be adopted as the high explosive of our service.
Such being the case, it is interesting to note the character and appearance of lyddite. Under the name of picric acid it has long been known. Picric acid is a nitro-substitution compound obtained by the action of nitric acid on a variety of substances; for example, indigo, silk, acaroid, resin, etc., but on the commercial scale the substance now generally acted on by the nitric acid is carbolic acid, and the equation of the process is simple, viz.:
Carbolic acid. Picric acid.
C6H6O + 3HNO3 =HC6H2(NO2)3O + 3H2O
Picric acid may, as written above, be regarded as a picrate of hydrogen, which latter element can be displaced by a metal to form an ordinary picrate—for instance, picrate of potassium, KC6H2(NO2)3O. It is a crystalline substance of a brilliant yellow color, and is intensely bitter to the taste. It burns with a very smoky flame. It is largely used as a dye, or constituent of dyes, and has not been usually considered as an explosive. Nor, indeed, does it usually behave like an explosive under ordinary circumstances, though under special conditions easily produced, it is capable of developing its now well-known formidable explosive properties. It may be burnt away in an unconfined state in considerable quantity without explosion, but the mere contact of certain metallic salts or oxides with picric acid in the presence of heat develops powerful explosives which are capable of acting as detonators to an indefinite amount of the acid, wet or dry, which is within reach of their deto- native influence.
Lyddite has proved to be a fairly stable compound, and safe in manufacture, store and transport. High temperatures abroad, or in ships’ magazines, do not affect its condition. When carefully packed into shells it does not “set back” like the nitro-glycerine in dynamite, on the shock of discharge, and so interfere with the “exploder,” or create a condition of extreme danger, from the likelihood of a premature. Several accidents have occurred during the firing of shells charged with lyddite, from this last mentioned cause, viz., the projectile prematurely exploding in the bore of the gun. But in the majority of cases the causes of the disaster were traced to faults in the shell, and were not due to oversensitiveness of the lyddite. Shells to contain it are now made of the best forged steel, which minimizes the prospect of prematures. The action of a powder fuse will not detonate lyddite, hence an exploder containing a few ounces of a safe and stable explosive is employed. It is inserted in a hole drilled centrally in the charge. The actual nature of the exploder used by the War Department is kept secret, but many metallic oxides and nitrates will detonate when brought into contact with picric acid at a high temperature, and this fact has probably been taken advantage of by the chemical department.
Clearly, then, the high-explosive shell has a very marked future before it, for artillery fire or active service; and, as foreign governments have gone even further than we have in the development of this terribly effective projectile—for one European navy, at least, has already introduced the melinite shell into its magazines on board ship—we must be prepared for attack with high-explosive shells in the next naval action, not only from shore batteries, but from the enemy’s vessels.
This is a serious outlook. Take the cases of the Majestic, Powerful, or Diadem types. Probably the 6-inch Harveyized steel armor plates upon the 6-inch gun casemates of these vessels would break up or explode outside the majority of high-explosive shells with which they might be attacked, and the side and barbette armor would certainly be sufficient to effect this desirable end; but the whole of the upper deck battery would be at the mercy of a few high-explosive shells which would burst within it, either from contact with a 12-pounder mounting or any other cause, and the whole of the main deck space from stem to stern, except the eight closed casemates, including the entire series of officers’ cabins, would be mere shambles in a quarter of an hour. If any one doubts the probability of this, let him go over the Resistance and judge for himself. She is an object-lesson the value of which cannot be controverted.
But, it may be asked, is there any remedy for such a condition of terrible insecurity as regards the officers and crews of our war-vessels in the future should the high-explosive shell do all that is expected of it? We believe that there is a partial remedy, but we fear not one that will commend itself in the eyes of our naval constructors. Looking at the Powerful or Diadem, the enormous freeboard given to these types cannot but excite observation. Is it excessive or not? That is the question. We cannot help thinking that, in running away from the evils of low freeboard, we have now run into the opposite extreme, if only the casemates can be adequately protected with armor against high- explosive shells, whilst vessels of so high a degree of freeboard are being built. We would cut them down in future and utilize the saving in weight of material thus released to provide a more extensive system of armor protection over the reduced surface of the ship’s sides. As the Powerful and Diadem types are at present, they are merely huge targets, which will be the sport and pastime of an energetic enemy who may possess guns firing high-explosive shells; their only chance in action would be to at once crush their enemy with their own high explosives, or run away and trust to the diminishing perspective of their form as they disappear over the horizon for the chance of not being hit. As regards our battleships, it is difficult to suggest anything; but surely a milieu could be designed between the Nile and the Trafalgar, which possess almost perfect immunity from the chance of destruction between decks by high-explosive shells, and the Majestic, which has none whatever about the main deck. Here is food for reflection.—Journal of the Royal United Service Institution.
AMERICAN AND EUROPEAN ARMOR PLATE.
The following important paper on the relative qualities and efficiency of European and American armor plate for warships has recently been submitted to the United States Senate Committee an Naval Affairs, by Captain O’Neill, Chief of the Bureau of Ordnance of the Navy Department:
While the great German concern has manufactured armor for many years, that made by the so-called Krupp process, which has of late attracted attention, dates from the test of an 11.8 in. plate, at Meppen, on September 15, 1895. In order to arrive at any satisfactory conclusions as to the superiority of Krupp armor over that manufactured up to the present time in the United States, or as to their relative merits, it is necessary to make a comparison of the tests applied and the results attained in both cases.
First, it should be observed that the much-advertised Krupp plates and English plates supposed to have been treated by the Krupp process are purely experimental or special plates, and do not, as far as can be ascertained, represent service armor, though they may result in setting a standard for future manufacture. From published statements, the Krupp plate referred to showed unusually good ballistic qualities, having successfully withstood the impact of three 12-in. armor-piercing projectiles, having striking velocities of about 1,993 foot-seconds. This plate, according to the formula used for computing velocities necessary for the perforation of face-hardened plates, should have been perforated by a 712.6 lb. (12-in.) projectile, having a striking velocity of 1,829 foot- seconds, whereas it successfully resisted projectiles having 164 foot- seconds greater velocity. None of the three shots perforated the plate, but from the fact that the back bulge, due to the third impact, was 3 in. high and slightly cracked, it would appear that the limits of its resistance had been almost reached; its most notable feature was the absence of cracks. It is worthy of note that in the test referred to the projectiles used were of Krupp’s own manufacture, and, while no doubt of good quality, it is impossible to make a direct comparison with projectiles or plates made in this country. A slight degree of inferiority on the part of the projectile enables a plate to make a remarkably good showing, and the fact that the plate was tested at Krupp’s proving ground with his own projectiles is not as convincing as it might have been under other conditions; nevertheless the test and its results seem to have been accepted, and the plate is referred to as the champion thick experimental plate.
In the London Times of August 20, 1897, is a report on an 11 11/16 plate made by Vickers, Sons and Co. (English), which was officially tested at Shoeburyness on August 19, 1897. It was attacked by three 12-in. Holtzer projectiles, weighing 714 lb., with 1,861, 1,868 and 1,860 foot-seconds velocity, which only penetrated 2 5/8 in. The plate successfully withstood the attack without cracking, and made a record about equal to the Krupp plate. By calculation it should have been perforated by a velocity of 1,814 foot-seconds, whereas it was not perforated with a velocity of 51 foot-seconds greater. The plate was called a nickel Harveyed plate; but as Messrs. Vickers have adopted the Krupp process, and dwelt on its excellence for thick plates, it is extremely unlikely that for this important test a Harvey process plate was submitted. The English Engineer, referring to this test, says: “We would again finally express the wish that we could try the powers of other projectiles besides those of Holtzer; he himself has protested against his 6-in. shot delivered in 1889 being taken as a sample of what he could now supply, excellent as they were for their day. Cannot Elswick—Sir W. G. Armstrong, Mitchell and Co. supply us with some of its Wheeler-Sterling (American) shot? It is only fair to our own plates to forestall the objection, which will naturally be made abroad, to calculations based on our trials made with Holtzer shot only.” Here we have two tests of what are considered superior thick plates treated by the Krupp process, but with some doubt as to the quality of the projectiles used.
On May 29, 1897, the Carnegie Steel Company, U. S.A., presented for test at Indian Head a 12-in. experimental plate of re-forged nickel- steel face-hardened armor, which was attacked with one Holtzer and one Wheeler-Sterling 12-in. projectile. There were no cracks. The first impact was with a Holtzer armor-piercing projectile weighing 850 lbs., with striking velocity of 1,811 foot-seconds; the point of the projectile just perforated the back bulge. The projectile, which seemed to be a good one, broke up; some few fragments got through, but the bulk of it fell in front of the plate. The Wheeler-Sterling projectile of 850 lb. weight was fired with a striking velocity of 1,769 foot-seconds; it smashed on the plate, a portion of the head remaining in the impact. By the formula this plate should be perforated by a 12-in. projectile of 850 lb., with a velocity of 1,696 foot-seconds, whereas it was just defeated by a velocity of 1,811 foot-seconds—i. e., 115 foot-seconds more than that required for perforation. The Carnegie plate, to have been equal to the Krupp plate, should have defeated an 850-lb. projectile at 1,846 foot-seconds; it fell short of it by 35 foot-seconds. The angle of impact in the case of the Krupp plate was 9 deg. from the normal, while in the case of the Carnegie plate the impacts were exactly normal. The former plate was slightly cracked after three impacts, while the latter showed no signs of cracking after two rounds. All in all, it may be fairly said that this Carnegie plate is fully as good as that of Krupp. In comparing the tests, the velocities used must not alone be considered, but the striking energy due to weight and velocity, as the projectiles used against the Carnegie plate weighed 850 lb., as against 712.6 lb. of Krupp and 714 of Vickers.
None of these three were service plates. The two former are quoted to illustrate the development reached abroad with thick plates treated by the Krupp process, and the latter that reached in this country by other means than the Krupp process, showing that the difference is slight.
There is no question but that Krupp armor has been, and is, equal to, if not superior to the armor of England, France, Russia, and Austria, but it is equally certain that armor made in this country has been fully equal to any service armor made abroad.
It is reported that on account of the good showing made by Krupp with his 11.8-in. plate, he received a contract for armor for the Russian battleship Poltava, a vessel of 10,950 tons displacement, carrying a 15.7- in. belt and turrets of 10-in. thickness.; but the nature of the ballistic requirements for this armor are not given. From the fact, however, that the Russian armor made in this country was not required to withstand as severe a test as that made for United States vessels, it is reasonable to suppose that the test required for the Poltava armor was not unduly severe. The price paid for this armor was £104 15s. and £108 11s. per ton, delivered in St. Petersburg.
The advent of the Krupp plate evidently created some stir among the British armor makers, for it was soon reported that they had adopted his process, and in March, 1897, the English firm of Vickers, Sons and Co. presented for test a 6-in. plate, which was officially tested, under the direction of the British Admiralty. It successfully resisted, without perforation or serious cracking, the attack of five 6-in. Holtzer projectiles of 100 lb. weight, having a striking velocity of 1,960 foot-seconds. The plate was reported as of Harveyed nickel steel, containing 4 per cent, of nickel, but is believed to have been treated by the Krupp process, as Vickers is known to have acquired it. The test applied to a 6-in. plate in the United States is less severe than that given to this experimental plate, and heretofore has consisted of one low velocity or cracking shot at 1,472 foot-seconds, and one high velocity shot for penetration at 1,959 foot-seconds. The calculated velocity—verified by practice— for the perforation of 6-in. plates by a 6-in. projectile is 2,084 foot-seconds, and it is proper to say that while our acceptance test is lower than that applied to the Vickers plate. Six-inch plates of American manufacture, have shown on subsequent attacks that they were capable of standing much higher velocities of impact than those required or than those applied to the Vickers plate. Six-inch plates of American manufacture, not special plates, but for ordinary service or for test of projectile, have successfully resisted numerous impacts with velocities of 1,986 foot- seconds, and in January, 1897, a Carnegie 6-in. plate furnished to test projectiles received impacts from 35 6-in. projectiles, the majority of them at velocities greater than those required to insure perforation of ordinary service plate. It must again be noted that the Vickers plate was attacked by Holtzer projectiles, which renders it impossible to make an exact comparison with American plates tested with American projectiles. The most recent Admiralty requirements are that a plate 8 ft. square by 6 in. thick shall resist five Holtzer steel projectiles of 100 lb. weight at 1,920 foot-seconds striking velocity without serious cracking, but we cannot learn as yet that any contracts have been made under these requirements.
Brown and Co. on July 20, 1897, submitted two 6-in. plates, which were officially tested by the British Admiralty under the same conditions as the Vickers plate, and both successfully fulfilled the requirements. In July, 1896, a 7-in. re-forged plate, representing the 8-in. turrets of the U. S. S. Iowa, made by Carnegie, after passing the regular ballistic test for acceptance, consisting of two impacts of a 6-in. projectile at striking velocities of 1,620 and 1,816 foot-seconds, giving a penetration of 2 in. and 3 in. respectively, was further tested with ten 6-in. projectiles of 2,100 foot-seconds, giving penetration of from 2 in. to 3.75 in.
In September, 1896, the British Admiralty tested a 6-in. plate made by Cammell, under circumstances similar to the test of the Vickers plate; it was reported as of Harveyed nickel steel, and made an excellent showing, but not quite equal to that presented by Vickers. Very likely this plate was treated by the Krupp process.
Beardmore, in Scotland, is reported to have taken a contract for armor for a Danish monitor, under ballistic requirements as high or higher than the Vickers plate quoted, and is said to have thrown up the contract.
No conclusive results or wholly satisfactory information concerning the value of the so-called Krupp process can be arrived at except by means of tests made by ourselves.
The American armor makers have acquired the rights to use it, because they wish to bid on foreign contracts, and to do so must be on an equality with foreign manufacturers. They are not prepared to make armor by the Krupp process, and cannot even state approximately when they will be able to submit a trial plate—though they expect ultimately to do so—and cannot guarantee that their first effort will be successful. They say they would not be filling at the present time nor the near future to take a contract under materially more exacting ballistic requirements than the last contracts for armor made by the Krupp or any other process, nor can they name a price for such armor.
As an item of interesting information, the last bids for Russian armor, the contract for which has not yet been awarded, are given, as follows; times for delivery, fourteen to eighteen months:
Vickers, Sons and Co., £116 16s. per ton; John Brown and Co., £113 18s. per ton; St. Chamond, £98 to £109 12s.; Le Creusot, £99 12s. to £113 12s.; Chatillon, £97 5s. to £112 12s.; Marrel Freres, £106 to £76 8s.; Krupp, £112 9s.; Dillingen, £111 17s.; Bethlehem, £106 2s.; Carnegie, £106 2s.; Wilkowitz (Austria), £90 9s.
My convictions are that armor manufactured in this country is fully equal to the best service armor yet manufactured abroad; that the tests as heretofore applied have been such as to secure a high standard, and that they are as severe as those heretofore applied abroad and represent more fully the actual quality of the armor supplied, more so than does the method of testing in vogue in England; that the armor presented in this country would have withstood tests considerably more severe than those to which it was subjected, and that the tests are and have been reasonable to the contractors, and so drawn as to carefully protect the interests of the Government. In the specifications recently prepared, which it is prepared to use in case of future contracts, a new table of velocities has been inserted, making the tests more severe than heretofore.
In testing armor in this country the plates of a group are carried on together until all arc carbonized; there is usually one more plate than the number required; the inspector at this stage selects the plate which in his opinion is the poorest of the group for the ballistic test. It is understood that in England a small plate or plates of the size and thickness submitted by the armor manufacturer for the standard of his manufacture, is carried along with the group, and such plate or plates are used for the ballistic test instead of one of the plates of the group, so that their test is not as representative a one as is ours. It is the custom for the armor makers of Great Britain to submit from time to time experimental armor plates for test. Such plates are tested by the Admiralty, and those making the best records are adopted as the standards which must be reached by the manufacturer to whom a contract is awarded. This naturally leads to considerable rivalry among the armor manufacturers, and the extensive ship-building programmes always being carried on in England, and the natural desire for prestige, warrant the expenditure of time and money to develop new and improved quality of armor, and while the manufacturers may combine to regulate the cost of armor for ships of the Royal Navy, as England builds ships of war for several foreign governments, the makers of what may be termed “champion plates” naturally stand the best chance for orders, both domestic and foreign; hence the incentive to excel is very great. It will be observed that there is no fixed ballistic standard except such as is made by the test of champion plates.
In this country the conditions are somewhat different, the Navy Department having heretofore established the ballistic requirements for all armor manufactured, the last ones being based upon the de Marre formula for determining the velocities necessary to insure perforation of high carbon steel plates and backing, plus fifteen per cent, for face-hardened armor. The specifications for armor for the Kearsarge and Kentucky are based upon the foregoing, and the actual velocities used against the ballistic plates, representing groups of armor, are. in the case of thick plates, about 14½ per cent, lower than that required for perforation for the high velocity shot, and about 35 per cent, less for the low velocity shot; for thin plates the high velocity shot is about 20 per cent, less than that required for perforation, and about 30 per cent, less for the low velocity shot.
These requirements seeming somewhat irregular, the new proposition is to fire two high velocity shots, both of which have a velocity of 17 per cent, less than that required for perforation. After the first shot there shall be no through crack in the plate, nor shall the projectile or any fragment thereof pass entirely through the plate and backing, and no part of the shell is to pass, on the second shot, entirely through the plate and backing. It is believed that these requirements insure armor of as good resisting quality as is in use in any country. It is impossible for any one to say that the maximum degree of excellence has been reached in the manufacture of armor; and in this country, where the demand is so limited, the best way to encourage the development and improvement of armor would be to make the ballistic requirements as high as is prudent and reasonable, and when making contracts to offer a premium of a fixed sum on such ballistic groups as may excel, by some specified amount, the contract requirements. This is the method adopted in France; a premium of 5 per cent, on armor at £80 would be but £4 per ton, or £10,000 on 2,500 tons of armor at that price, supposing it all earned the premium. It is not unlikely that the American armor makers would be willing to accept higher ballistic requirements if they were permitted to carry along with each group special plates of 6-in. thickness to be used for the ballistic test, as it is reported is done in England, but such a measure would not be calculated to secure service armor of the best quality. At present the Bureau of Ordnance sees no good reason for increasing the ballistic requirements beyond the point proposed and heretofore stated, but does favor the payment of premiums for greater excellence. While the English firms of John Brown and Co., Cammell and Co., and Vickers, Sons and Co., the French firm of St. Chamond, and the American firms of the Bethlehem Iron Company and the Carnegie Steel Company have acquired the right to manufacture under the Krupp process, the development of that process and its status in this country at the present time is not such as to warrant its consideration in connection with the armor for the new battleships Nos. 7, 8 and 9. The future alone will reveal its value, so far as its manufacture in the United States is concerned. The proposition outlined as to premiums will probably secure the best armor that can now be made in this country for these vessels.
An experimental plate is now being made in this country, and should be ready for test in a few weeks. It is made by the Chase-Gantt process; it was cast 18 in. thick, in a mould faced with ferrochrome and some other substances. It was then forged down to 10 in. in thickness and tempered, that is, face-hardened. It is not known as yet with what degree of uniformity such plates can be reproduced, or what ballistic showing it will make, nor at what cost such plates can be produced, but probably cheaper than by the Harvey process.
It is reported from abroad that the Krupp process will be more costly than the Harvey process. The Krupp process is not patented, but is a trade secret. It is not improbable that the carbonizing is done by means of a hydrocarbon gas instead of the former method of cementation. It has been learned that the Russian government did not accept any of the bids herein referred to, and it was understood that they contemplated making the armor themselves; it is also rumored that the contract will again be placed on the market.
In 1887 and 1890 this Government offered premiums for armor possessing qualities superior to contract requirements, but the introduction of nickel steel and face-hardened plates upset calculations for the time being; the problem is now sufficiently well understood to warrant a return to that method. There is a clause in all our contracts which provides that any new or improved methods that may be developed may be required by the Government, but this implies modification in price, and is so stated.—The Engineer.
TEST OF A SPECIALLY PREPARED PROJECTILE.
An official trial of a specially prepared projectile was successfully carried out at Messrs. Vickers, Sons and Maxim’s range at Swanley, recently, in the presence of representatives of the Admiralty and War Office. The trial was of considerable interest, as it is well known that after a gun has been fired many hundreds of rounds the velocities fall off to some extent, due to erosion and other causes. The point of difference whereby this projectile differed from others was that an arrangement was screwed on to the base of the shell by which a specially prepared ring was made to expand in the eroded portion of the bore so as to overcome the injurious effect of erosion, caused by smokeless powders, as well as to prevent the shot being over-rammed, should the bore be worn by this or other causes. The general principle of the gas check depends upon the compression of this specially constructed ring by an annular copper ring, which conveys pressure to the specially constructed ring in such a manner that the specially constructed ring makes a perfect metallic seal against the bore, and completely prevents any gas at a high temperature and pressure passing the base of the shot, and hence does away with the principal cause of erosion in guns. Four rounds .were fired with this specially banded shot, and four with the ordinary service shot, and it was found that the whole of the energy of the gun was restored after upwards of 250 rounds had been previously fired. The actual ballistics obtained were 2,694 feet per second for a pressure of 13 tons with a 25-lb. charge of cordite. By increasing the charge by a moderate amount and slightly increasing the initial chamber pressure, a velocity of 2,900 feet per second could reasonably be expected. It is claimed that this simple application is capable of being applied to almost any design of shell at a very moderate cost, and by its application it is confidently expected that guns after firing many hundred of rounds will be equally efficient, as far as energy is concerned, to a new gun.— Journal of the Royal United Service Institution.
THE VICKERS 6-INCH QUICK-FIRING GUN.
It would be difficult to overrate the importance of efficiency in a 6-in. gun at the present moment. In action the heavy guns fire but slowly, their effect may be very great, but the number of rounds got off from them in a critical period may probably be too small to eliminate the elements of uncertainty. The very light quick-firing pieces are so much exposed that it is a question if they could be fought at all in close action. Consequently the fire that many officers depend on mainly is that of the heavier quick-firing guns, and in the British service these are 6-in. pieces, protected by 6 in. of steel in all our best vessels. Speed and power in our 6-in. quick-firing guns, then, is especially to be desired, and hence the importance of the 6-in. gun brought out recently by Messrs. Vickers, first tried on board the Pincher gunboat at Portsmouth on October 21 last, subsequently at Shoeburyness, and adopted for the service in January last. Its length of bore is 45 calibers, and its weight 7 tons 8 cwt. It is of wire construction, and proportioned to bear the prolonged pressure of its large charge of 25 lb. of cordite during the passage of the shot up the bore. It will be seen that the mounting carries a small curved shield of special nickel-treated steel, which has been proved to possess high resisting power, although the steel is able to be brought to the abrupt curve needed for the shield.
There are three leading features in the gun as put forward and tried: (1) great energy; (2) special breech action, giving ease and speed of working; and (3) obturation sufficiently complete to enable the metal cartridge commonly used in quick-firing guns to be dispensed with. On the day of trial at Portsmouth a muzzle velocity was attained with a 100-lb. projectile of 2,784 foot-seconds, implying a muzzle energy of 5.373 foot-tons, and a perforation of 22.7 in. of iron by Tresidder’s formula. This, it need hardly be said, is extraordinary, the greatest perforation laid down in the service table for a 6-in. gun being 13.9 in. of iron. In stating this, we feel it necessary to recognize that it is extremely difficult to maintain such a performance as the gun continues in use. Very rapid fire with very large charges of cordite involves an amount of wear that it is very difficult to resist. Messrs. Vickers, however, have confidence in having arrived at effectual means of prevention.
To come to the second leading feature, that is, ease and speed of working. The screw is made on a system embodying the Weling patent. For the interrupted thread of the French system is substituted in the portions or segments differences in radius exceeding the height of the screw thread, which may consequently be continued throughout, except where a break or interruption is made to take the segment whose thread stands highest. This succession of steps may be repeated. It occurs twice in the 6-in. gun. In the 12-in.gun the succession of steps is repeated three times. In each case there is a considerable gain in the length of screw thread bearing, as compared with the French interrupted system. The screw and mechanism of the 12-in., as may be seen, are very light compared with the large diameter of the bore. The advantage is perhaps still more apparent in the 12-in. than in the 6-in. In this three- quarters of the circumference of the screw are used for effective thread section, only one-quarter of the circumference being non-screwed. On this account the screw can be made lighter and shorter than in other types, and consequently a lighter carrier can be used, and the manipulation is rendered more easy and rapid. Further, the shortness of the screw admits of the gun itself being shortened at the breech, that is at the heaviest part, and great weight is saved which can be utilized elsewhere. Both the 12-in. and 6-in. mechanisms have practically the same system of firing gear. There is an automatic tube-ejector which throws out the primer when the breech is opened. The tube can be placed in the vent either with the breech open or closed, and in the case of a misfire it is not necessary to open the breech to withdraw the tube. Safety gear exists, rendering it impossible to fire the gun without the breech being closed and locked either on the electrical or the percussion-firing system.
Returning to the 6-in. quick-firing piece, the third leading feature in the gun is obturation dispensing with the use of a metal cartridge. This is facilitated by the shortness of screw, so that it has been found that the De Bange obturator can be rendered efficient. The advantages of this are obvious; the doing away with the metal case saves weight and magazine room, and saving of weight facilitates the rapid and easy working of the gun. There is also probably a saving in expense. No ejection of case being required, mechanism is simplified. Throughout the trials at Portsmouth and Shoeburyness the breech mechanism worked with complete ease, the tube was satisfactorily ejected automatically, and the obturation was complete. The heating of the metal was also watched, and considered to be well under the needed limit of temperature.
The Shoeburyness trial took place on January 13 in the presence of the representatives of the War Office and Admiralty. The object of this further trial was to test the accuracy of the gun after having fired upwards of 200 rounds, including the rounds fired at the proof of the gun; and also to submit the gun to a further test for rapidity, under conditions of service, using a 100-lb. shot, a cordite charge, and service primers. The trial commenced with a series of ten rounds, the result of which showed that the accuracy of the gun had not fallen off in consequence of the great amount of work already done by it. On the contrary, on two occasions the projectiles pased through the same hole in the target.
Suspension of firing then occurred, due to the weather becoming overcast, but in the afternoon it cleared, and the rapidity series was successfully completed. This series was conducted by a crew of seamen gunners specially sent by H. M. S. Excellent for the purpose, and were in charge of Lieutenant-Commander J. Murray Aynesley, the experimental officer of the gunnery school at Portsmouth. Thirty-six rounds were fired in four minutes forty-seven seconds, and this time included taking temperatures of the vent head, which operation was considered desirable, owing to the very rapid rate of fire. This rate of fire gives practically one round per each eight seconds, or at the rate of one hundred rounds in thirteen and one-third minutes, which, for practical considerations, allowing one hundred seconds for cooling during the hundred rounds—this extra time would probably be necessary for the supply of ammunition on board ship—would give a rate of fire of one hundred rounds in fifteen minutes.
For a short series of rounds such as one would expect in an engagement of, say, from ten to twenty rounds fired intermittently, an even greater rate of fire would be obtained. Analyzing the rounds fired during the trial, the maximum rate of fire attained was one round in six and one-half seconds, and eight rounds were fired each taking seven seconds, and another eight rounds each taking seven and one-half seconds. The other rounds varied from eight to nine seconds.—The Engineer.
VICKERS’ QUICK-FIRE FIELD GUN.
A trial of a quick-fire gun of Messrs. Vickers took place at Messrs. Vickers’ range at Eynsford this week, in the presence of officers representing the War Office and Admiralty. As most of our readers are aware, the difficulties of applying quick fire to field guns are—first, the fact that it is esential that the gun should not require relaying each time it is fired; and secondly, the fact that the metal cases of quick-fire ammunition add greatly to the weight to be carried, and are troublesome. The recoil in guns mounted on decks and behind breastworks is generally partly checked, and the gun probably recovers its original position and laying by the action of springs, etc. In the field this has never hitherto been completely carried out, but there are various more or less successful arrangements. Vickers claim to have achieved this so as to render raising up unnecessary, both with howitzers and high- velocity pieces. The following description is supplied: “The recoil and subsequent return of the gun to the firing position are operated by a specially constructed device fixed under the protection of the trail, which is arranged to allow both the gun and mounting to recoil, thereby making use of the whole available mass for overcoming the energy of recoil, the result being that the jump is eliminated and the gun run out into the firing position without alteration of the slight alignment. One of the special points by which the system is characterized is that it readily admits of its application to existing artillery without any serious modification to the existing type of mounting, and the mounting when altered is, within a few points of percentage, equal in efficiency to an entirely new quick-fire field equipment. The total weight of the gun and mounting complete, including mechanism, wheels, quick-firing attachment, tools, etc., is 19 cwt. The weight of the limber is not here recorded, as this depends on the weight of the ammunition intended to be carried by any particular equipment.
“Twenty-seven rounds were fired in all, with charges of 16¼ oz. of ballistite, the weight of the shell being 13¼ lb., and a velocity of 1,650 foot-seconds was obtained for a pressure of 14 tons. Two rounds were first fired to exemplify generally the working of the system, after which fifteen rounds were fired for rapidity, each round being carefully laid on the target. These fifteen rounds were fired in 67 seconds, which gives a rate of fire of 13½ rounds per minute. A second series was then fired, during which the gun was very carefully laid and was placed pointing deliberately forty degrees off the target, and the time was taken from the gun’s crew working the gun from this position into the alignment, and proceeding with the firing in such a manner as would take place when a gun was being taken into action on service, the time being taken for unlimbering. Under these circumstances ten rounds were fired in 125 seconds, or at the rate of five rounds per minute, each of the rounds being carefully laid on the bull’s-eye. Six rounds were then fired from a mountain equipment at the 1,000-yards range, when excessively good shooting was obtained, but the shooting under these circumstances is not now specially reported, as the equipment was one of which the results are well known, and which is being successfully used in Egypt, this type of gun having made excellent shooting recently at the battle of the Atbara.
“It is of interest to note that the Egyptian Government are now in possession of six complete batteries of these guns, which use shells of 12½ lb., and 20 lb. double shell when desired.
“At present metal cartridges are used, but it is claimed that they can be dispensed with, as in the 6-in. quick-firing gun, the De Bange pad being used.”—The Engineer.
A NEW METHOD OF MAKING HARD-FACED ARMOR.
Taking advantage of the fact that by suitably controlling the process of cooling, it is possible to obtain some of the newer alloys of iron with nickel, cobalt and manganese in either a hard or a malleable condition, M. Jean Werth, manager of the Société Anonyme des Hauts Fourneaux et Aciéries de Denain et Anzin, has devised a new process of making armor plate. M. Werth’s contention is that the plate should have the same chemical composition throughout, and that the hard face should be obtained entirely by a process of tempering. Ordinary carbon steel in large masses cannot be tempered satisfactorily, but when alloyed with suitable proportions of nickel, cobalt or manganese it is possible to obtain the metal in a hard state by heating it up to a bright red and allowing it to cool in the air; whereas, if heated only to a dull red and cooled, the metal will be malleable and comparatively soft. The steel used by M. Werth is open-hearth metal, free from sulphur and phosphorus. It contains from 5 per cent, to 15 per cent, of nickel or cobalt, and from 2 to 12 per cent, of manganese, whilst within certain limits silicon, chromium or tungsten may be present without interfering with the process of tempering. In its soft state such a steel has a tensile strength of 110,000 lb. to 140,000 lb. per square inch, and a strip 154 in. thick can be bent without cracking round a radius equal to its thickness. After the plate is completed, it is tempered by making it part of the side or bottom of the furnace. The face next the fire thus becomes heated to a bright red, whilst by means of water or air the temperature of the back face is kept down to 800 deg. or 900 deg. Fahr. To insure good results the heating is effected very gradually, the plate being put into a cold furnace; and by preference gas fuel is employed in the latter. Another method of effecting the heating, which is, however, only applicable to flat plates, is to immerse their front faces in a bath of red-hot lead, the temperature of which is maintained very uniform. When ready, the plate is removed from the furnace and cooled at the back, until the front face has sunk down to a temperature of 800 deg. to 900 deg. Fahr., when no further attention is required, though if warped it can now be straightened before the cooling is finished.— Engineering.
THE UNITED STATES NAVY-GOOD AND BAD POINTS.
The present war will certainly throw much light on various problems of naval architecture which are now but vaguely understood, and it may solve them completely and satisfactorily. Already the superior points of the navy have been demonstrated and its weaknesses made manifest. The most important and prominent fact has been the reliability of the ships, considered as a unit, and the capability of the several types for the work they were designed for. A continuous and hard duty for several weeks, cruising under high pressure, and repeatedly employing all the guns, has failed to show a single defect of a serious nature in either hull, machinery or armament. The protective qualities of the boats have not been tested in the slightest degree.
Too much praise cannot be extended to the designers and builders of the propelling machinery. The uncertainty which has been felt as to whether this portion of a naval vessel would stand long-continued service has been removed. That this doubt existed was shown by the statement of the late Admiral Meade, at a meeting of the Naval Architects and Marine Engineers, two or three years since, that he would like to have one of the fast cruisers attempt to follow one of the Atlantic liners in a trip to Europe, the object being to practically test the staying qualities of the cruiser. The seagoing ability of the battleships has been proved by the wonderful voyage of the Oregon, which joined the fleet off Cuba in every respect able to do her full share of the work.
The monitors were intended for coast defense. Their limited coal capacity and consequent exceedingly small radius of action make it impossible for them to be independently useful at any considerable distance from a base of supplies. This was illustrated during the movement of the fleet toward Cuba, when coaling at sea was necessary, and when the speed of the fleet had to be regulated by that of the monitors. Those characteristics also prevent the monitor class assuming a position in a naval engagement—it must be content to fight in the position its quicker enemy chooses to place it. Its seagoing ability has also been criticised. For coast defense the monitor, with its tremendous power, ample protection and small target presented, will undoubtedly prove to be of the greatest use. An unknown factor is found in the ram Katahdin. Whether this vessel will occupy a niche peculiar to itself remains to be seen.
The big guns and their turrets have worked without a hitch. At the present time the life of these guns, or the number of times they can be fired with full service charges, is not khown with any degree of certainty. It is possible that the experience now being gained may lead to experiments with guns of greater caliber length than any now employed. Experiments have been made abroad with lengths as great as 50 and 60 times the bore, but the results are more or less uncertain. The American built-up gun would appear to lend itself to this extension, and if such should prove to be the case the advantages gained would be of the utmost value. The good resulting from the use of smokeless powder has been shown by the New Orleans. According to the dispatches, the rapid dissipation of the light smoke from her guns permitted their being handled more rapidly than those using ordinary powder.
In addition to a general weakness in numbers in all the types, the American Navy is particularly feeble in torpedo boats and torpedo-boat destroyers, and in high-speed, partially-protected scouts or dispatch boats.
With so many experts watching for points of excellence or features of weakness, we may expect a thorough account at the close of the war. With the public thoroughly aroused to the necessity of possessing the best vessels, equipped in the most modern way, there can be little doubt that Congress will promptly vote the necessary appropriations.— Iron Age.
RIGHTS AND DUTIES OF BELLIGERENTS AND NEUTRALS.
At the Royal United Service Institution, on May 19, Mr. J. Macdonell, LL. D., Master of the Supreme Court, delivered a lecture on “Recent Changes in the Rights and Duties of Belligerents and Neutrals according to International Law.” Sir Robert Giffen, K. C. B., presided.
Mr. Macdonell said that when he arranged with the secretary, about six weeks ago, respecting his lecture, he did not anticipate that the subject would have the living interest which it now possessed. He proceeded to point out how international law was in a state of rapid transition, and that much that was taught in books on the subject had become obsolete. Among the great changes affecting international law were the decline in the belief in the “law of nature” and in the influence of Roman law; the doctrine of the equality of States was also no longer accepted as it once was; international law was now based on a community of civilization, and another great change was the growth of “military realism”—a spirit which found eloquent expression in much of the military literature of Germany. In dealing with the chief recent changes which have taken place in international law, he took as the starting-point the close of the Crimean war. In 1856 the great powers issued the Declaration of Paris, of which the history was still shrouded in some mystery. Neither Lord Clarendon nor Lord Cowley, the diplomatists more directly concerned, gave a full account of the negotiations; the only detached statement was one published by M. Drouyn de Lhuys, who was French foreign minister at the time. According to that statement—it was borne out by the remarks which fell from Lord Clarendon—that declaration would have been made by the bulk of civilized States whether we had acceded to it or not. Referring to the abolition of privateering, he remarked that perhaps the growing sense of humanity and the recollection of the squalid abuses connected with privateering had something to do with its disuse. But much was due to this fact—the transformation of a merchant vessel into an efficient cruiser was not so easy as it was in the days of Paul Jones or Jean Bart. When that transformation was practicable there was little in the Declaration of Paris to prevent it. Article 2 provided that “the neutral flag covers enemies’ goods, with the exception of contraband of war.” This closed a long controversy, in which England had, on the whole, consistently maintained her right to seize an enemy’s goods wherever found. It was not clear that we could have prevented a general affirmation by the civilized world of the principle, “free ships make free goods.” It was not clear that we could have maintained our ancient principle without provoking the hostility of neutral nations, and it was still less clear that we could now rescind what we did in 1856. One could not lose sight of the fact that exemption from capture on sea was probably for a long time to come out of the question. Such exemption would be in war to the supreme advantage of England, which stood to lose so much. The Declaration of Paris did not deal with contraband of war, and he could not say that as to this in recent years, either here or elsewhere, there had been any distinct change. No prize courts had for many years sat in' this country. When they went to war they would see them applying doctrines and principles of a startling character, and highly unfavorable to neutrals—doctrines and principles formed at a time when belligerents were a law unto themselves. Members of Parliament had lately asked the Government again and again whether they intended to prohibit the exportation of contraband. The Crown had power under the customs act, 1879, to prohibit the exportation of certain kinds of contraband—a power, however, which was rarely exercised. A vessel might be contraband, and the fitting of it out might also be an infringement of the foreign enlistment act, but, speaking generally, there was no power to prohibit the exportation of contraband; the risk of capture was the only penalty. The foreign enlistment act of 1870 made our neutrality law more rigorous than that of any other country. It was the outcome of the complaints of the United States Government as to the defects of our neutrality law in allowing the escape of the Alabama. The English act of 1819 was based on the American statute of 1818, but was in several respects more stringent, and, as he had said, the statute of 1870 still further increased the stringency of English law. But no change of any kind was made in the United States statute. The consequence was that many things punishable here were not so according to American law, and they were not punishable under most other systems. As they were all aware, too, our Government undertook by the Treaty of Washington of 1871 to observe in the future three rules then formulated and to bring them to the notice of other countries. No other nation had adopted these rules, which many jurists treated as unreasonably onerous to neutrals. He was inclined to think that the act of 1870 and the rules of 1871, properly understood, did not go beyond what was reasonable; but it was more heroic than prudent to admit the existence of these duties without insisting on or asking for reciprocity or giving some explanation of the sense in which we understood them. The only occasion on which these rules were construed— at the Geneva arbitration—they received an interpretation which every English lawyer repudiated. In recent wars in which maritime operations have been carried on on a large scale, the chief controversies had turned on the duties of neutrals to belligerents. The events of the last few weeks suggested several desirable modifications in the interest of neutrals. A neutral must be prepared to put up with many inconveniences from operations conducive to the termination of war, but it was plain that the present laws of war permitted of acts which might profoundly injure the neutral without, perhaps, greatly aiding the belligerents or conducing to the close of hostilities. Recalling the effect on the price of wheat here and elsewhere, the far-spreading consequences of the rise caused by vague alarms of capture, let them conceive what would follow from a blockade, maintained even for a few weeks, of the chief American ports. Suppose that in a war between Germany and Russia the ports of the latter were sealed, and that no wheat from Russia was procurable at a time when harvests in America and other countries usually supplying us with wheat were bad, should all neutrals consent to starve in order that the ring might be kept for the combatants and the game of war be played out in the good old way? For the common benefit of civilization, the maintenance and use of certain machinery, plant and services were necessary. The treatment of submarine cables in time of war was a still more difficult and important question, and one as to which international law had so far failed to give any clear guidance. No one could say with confidence what would be its development as to this point. An international convention was entered into at Paris on March 14, 1884, for the protection of telegraphic communication by means of submarine cables; but Article 15 expressly stated that the convention was not to interfere with belligerent rights. Probably effectual safety against the danger here referred to was to be found in the multiplication of lines of communication; but pending extensive developments of telegraphic enterprise it was hard to contemplate calmly the possibility of England’s being cut off from India or some of her colonies, not by her enemies, but by a State professing to be friendly to her, in order to injure some other State. It seemed to him that in any satisfactory convention there should be an article binding the signatories not to cut or injure cables connecting countries with their colonies or dependencies. That the strict enforcement of belligerents’ rights as laid down in the text-books would be here ruinous to neutrals, that the new maritime law, slowly disengaging itself from precedents and traditions, must here, as elsewhere, take greater notice of the interests of neutrals—that was the reflection with which he ended. —United Service Gazette.
BELLIGERENTS AND NEUTRALS.
The second and concluding lecture by Mr. J. Macdonell, C. B., LL. D., Master of the Supreme Court, on “Recent Changes in the Rights and Duties of Belligerents and Neutrals according to International Law,” was delivered on the 2nd inst. at the Royal United Service Institution. Major-General J. F. Maurice, C. B., presided.
Dealing with the recent practice of beginning hostilities before a formal declaration of war, which, it will be remembered, caused difficulty in the American-Spanish war owing to the capture of Spanish and French prizes, Dr. Macdonell pointed out that this was no new source of trouble. Although the ancients always first declared war, the Romans making the occasion one of pomp and ceremony, there was no expressed condition, and a change was introduced in the last century. Great Britain, for instance, refused to give up prizes to France, although taken before the declaration. Such declaration was no longer regarded as obligatory, and even the withdrawal of diplomatic agents might not precede the outbreak of hostilities. Such change and difference of opinion might involve great difficulties, say, with shipowners or shipbuilders, whose obligations as subjects of neutral States could not clearly be recognized. Thus, the lecturer pointed out, a shipbuilder on the Clyde might hand over munitions of war to a belligerent after hostilities had been commenced in a corner of Africa, of the existence of which place the shipbuilder had never heard. Jurists were divided still as to when some of the great wars of this century actually commenced, and thus it was a matter of great importance that some agreement should be come to. On the subject of the severing of submarine cables, Dr. Macdonell had much to say, but he was clearly of opinion that a belligerent had the right to cut a cable even if it terminated on neutral soil, and he instanced the case of Britain being at war, and using the cable which touches at Lisbon for communicating instructions to colonial ports. Obviously the enemy would cut such an important line, which led to the suggestion that it was most undesirable for us to have important telegraphic connections through such small States, which were very liable to be coerced by a powerful enemy. Our trust should not be laid in any chapter of accidents to see us through such a difficulty. The lecturer alluded to the greater humanity of the soldier and of the recognized practice of saving national and private treasures, but he disagreed with most jurists in the view that the outbreak of war made void the debts of the citizens of one State to those of the other belligerent. He urged soldiers and the jurists to combine in the preparation of a first- class comprehensive manual for international guidance.—United Service Gazette.
TRIAL OF NEW TORPEDO NETS.
The new torpedo nets tried on H. M. S. Hannibal, have been definitely adopted for service, and the Hannibal, when commissioned, will be equipped with them. They weigh about 30 cwt. per net, half as much again as the old style, but are said to be “quite as easy to handle.” I have not seen them in operation, but “quite as easy to handle” is a vague term. Ships have been known to take nearly twenty-four hours getting out their nets, while others have done it in two hours. In part, of course, this has had to do with the crew, but structural peculiarities and often individual peculiarities of individual ships have had as much or more effect. In any case, however, the Admiralty are to be congratulated on their diligence and pertinacity in seeking to solve the problem that—as mentioned last week—both France and Germany have abandoned as hopeless. It is very nearly a cardinal axiom with modern naval officers, that if a torpedo boat finds a ship she will “get home” without much trouble. Of course, the ship’s safety lies in the immense difficulty of a boat finding her in war time. I have been in a “boat” and passed within torpedo range of a ship at anchor without a soul on board knowing it; the lost chance was only discovered when the ship opened fire some while after she had been passed by the way. On the other hand, I have known a torpedo miss at a range of 30 yards, or thereabouts, that is, one-tenth of what is considered almost certain range. A ship is a very small target when a boat is steaming fast. In theory, a torpedo will travel 1,000 yards, in experimental practice it will find the target nine times out of ten at 400 yards; in manoeuvres the chances are even that it will hit at 300 yards—in war time they will be certainly half that again. But on the other hand, the ship’s chances of hitting the boat are still less, nor is it proved that one hit, or even several, will stop a boat. From the time the boat is sighted until the torpedo is fired is—despite the manoeuvre claims of two minutes under fire—seldom over one minute, and to hit a boat enough to stop her way in sixty seconds will need some very good shooting.
In connection with torpedo boat attack and defense, it is pretty generally known now that the orders for war time are—fire at every boat. Whether it be friend or foe must be discovered later. It is a regrettable thing that in our annual manoeuvres we never properly test this question of what is to happen to the friendly boat, by allotting torpedo boats to each side. In connection with this, it is currently reported in the service that a well-known torpedo officer recently informed the Admiralty that he had a device whereby a friendly boat could make its presence known on board a battleship without visible signal of any sort. The Admiralty, however, refused to allow the money necessary to carry out the experiments, so it remains a secret; presumably it was some adoption of wireless telegraphy. The French are said to be in possession of some such device.
TRIALS OF DUTCH CRUISERS.
In our issue of February 21, 1896, we gave some particulars of the water-tube boilers which were to be placed in three second-class cruisers that were then being built for the Royal Navy of the Netherlands.
[TABLE: RESULTS OF TRIALS OF DUTCH CRUISERS.]
These vessels were the Holland, Friesland and Zeeland. It will be remembered that Mr. Andrae, the engineer-in-chief to the Dutch Navy, determined to try the result of a combination of small tube or express water-tube boilers and return-tube boilers in these vessels, and selected the Yarrow boiler as most suitable for the purpose. As a consequence, Messrs. Yarrow & Co. were commissioned to construct, at their works at Poplar, one Yarrow boiler for each ship, making three in all, and these were intended to act as examples for the remaining water-tube boilers required that were to be made in Holland. We have been furnished with the particulars of the trials of these vessels, but before repeating them it will be convenient if we give some details of the vessels themselves.
The Friesland has been built and engined by the Maatshappij voor Scheeps en Werktuigbouw Fijenoord at Rotterdam, an establishment of which Mr. Croll is the director; and the Zeeland by the Koninklijke Maatschappij de Schelde at Flushing, of which Mr. van Raalte is the director; whilst the Holland was built in the Royal Dockyard at Amsterdam, and engined by the Nederlandsche Fabriek van Werktuigen en Spoorweg Materieel at Amsterdam, of which Mr. Strumphler is the director. These vessels are 306 ft. long by 48 ft. 6 in. wide and 17 ft. 9 in. deep. The displacement is calculated at 3,900 tons with 400 tons of coal on board, the total coal supply being 850 tons. The vessels are twin- screw, and have triple-expansion engines with cylinders 33 in., 49 in. and 74 in. in diameter by 39-in. stroke. The propellers are 14 ft. by 16 ft., and have 60 square feet of surface. It may be noted that the propellers of the Holland turn outwards, and those of the other two ships inwards. The boilers, which are the most interesting part of the machinery, consist, in each ship, of two of the return-tube type, having a grate surface of 126 ft. and a heating surface of 4,005 ft. The eight water-tube boilers have 322 square feet of grate and a heating surface of 16,136 ft. As stated, Messrs. Yarrow made one boiler for each vessel, the remainder being constructed by the Dutch firms. The total maximum horse-power for which the boilers of each ship were designed to supply steam was 9,250 indicated. Of this, 2,250 horse-power was to be obtained from the two return-tube boilers, and the remaining 7,000 horse-power from the eight Yarrow boilers. The weight of the return-tube boilers with water was 120 tons, and that of the eight water-tube boilers with water 88 tons. The total weight of propelling engines and boilers and water, together with pumps, fans, funnels, floor-plates, ladders, and all other things which can be included under the category of propelling machinery, was for the Holland 635 tons, for the Friesland 611 tons, and for the Zeeland 570 tons. The Holland and Friesland have Weir’s feed-pumps and feed-heaters. The Zeeland is fitted with Yarrow’s automatic feed- control arrangement, and has a Worthington pump to each boiler, but has no feed-heater. There are steam steering engines, dynamos for electric light and for search-lights, air compressors for torpedoes, steam capstans, refrigeration engines, Sturtevant blowers for ventilating purposes and to supply hot or cold air, evaporators, feed-water filters, and other auxiliary machinery and fittings.
The results of the trials are given in the annexed table. The steam pressure in both return-tube and water-tube boilers was 200 lb. to the square inch.
The object of the Dutch naval authorities in adopting the combined arrangement of boilers was to gradually accustom the stokers to the new type. In three similar cruisers being built in Holland, and which are to be launched shortly, Yarrow boilers only are being fitted; there being twelve in each vessel.
It may be interesting to compare the results obtained on the trials of these vessels with those of the Diadem, which affords an example of our most recent type of cruiser. Putting the weight of the machinery in the three Dutch vessels at 605 tons and the mean maximum horsepower at 10,260, we have 16.9 horse-power developed per ton weight of machinery. If the weight of the Diadem’s machinery was 1.437 tons, and the horse-power developed 17,262 (see Sir John Durston’s paper read at the last meeting of the Institution of Naval Architects), it will be seen that 12.01 horse-power was developed per ton weight of machinery. It must be borne in mind, however, that the Diaderh’s full- power trial extended over eight hours, while that of the Dutch cruisers was but of four hours’ duration. If every allowance be made, however, there can be no doubt that the adoption of the express type of boiler gives an enormous advantage in regard to lightness of machinery, and therefore of speed; and it may be said generally that the results bear out the wisdom of the choice of the Dutch naval authorities.—Engineering.
SHIPS OF WAR.
[Chili.]
O’Higgins.
The Chilian cruiser O’Higgins, which has just completed a series of trials, including twenty-four hours’ seagoing speed, six hours’ full speed, gunnery, turning, and other trials all of which have been carried through with complete success. The O’Higgins was designed by Mr. Philip Watts; the keel-plate was laid in April, 1896; the vessel was launched in May, 1897; and she is now about to leave for Chili, complete in every respect; the period of her completion in less than twelve months from launch is exceedingly short, when her size is considered, and the seven months’ engineering strike which intervened is taken into account.
The dimensions of the O’Higgins are: Length, 412 ft.; beam, 62 ft. 9 in.; mean draught, 22 ft. At this draught the vessel displaces 8,500 tons, and carries 700 tons of coal, a complete outfit of provisions, stores, fresh water, etc., and all ammunition, torpedoes and equipment. This mean draught was maintained during the speed trials, which were made off the Tyne in the presence of Admiral Uribe and other members of the commission of Chilian officers appointed to superintend the construction of the vessel.
The machinery has been supplied by Messrs. Humphrys, Tennant and Co., and the boilers are of the Belleville type, being thirty in number, placed in three separate water-tight compartments. Owing to a strike of firemen engaged for the trial, the Chilian officers kindly gave the services of 100 Chilian stokers—part of the crew to take over the vessel when complete—and though these men were not accustomed to stoking the Belleville boilers, the trials were nevertheless carried through with complete success, an ample supply of steam being maintained throughout.
The full power of the engines is 16,000 indicated horses, but the twenty- four hours’ trial was conducted at about three-fifths full power, and 10,000 indicated horse-power was exceeded during the whole time, giving a speed of over 19 knots. Turning circles were made after the trial to test the manoeuvring qualities, and these showed that in 2 min. 6 sec. the O’Higgins could reverse her direction, both engines running full speed ahead, the tactical diameter being 3.4 times the under-water length of the vessel, the complete circle being less than three times her length; the heel of the vessel in turning never exceeded 4 deg.
The above trial was made on April 20, the full-power six hours’ trial with natural draught being taken on the 26th. The mean of six runs over the measured mile course, taken consecutively with and against the tide, worked out at 21.52 knots, the last four runs giving a mean of 21.7 knots, which may therefore be taken as the full speed of the O’Higgins. It should be mentioned, however, that the vessel had never been docked since her launch, and though sheathed and coppered, it is probable that a certain amount of slime was adhering to her bottom, and it was afterwards found that numerous copper sheets were dislodged at the launch and repaired in dock after the speed trials.
The gunnery trials were made on two days, and finally completed after the six hours’ trial, when, amongst other severe tests, seven guns were simultaneously fired direct ahead by an electrical discharge, no damage to ship or mountings resulting, with the exception of glass. These seven guns were three 8-in., two 6-in. and two 4.7-in. A similar test was applied aft, but with one 8-in., four 6-in. and two 4.7-in. The armament carried by the O’Higgins is not only exceptionally powerful, but is exceptionally well protected, all the four 8-in. guns being separately mounted on 6-in. armored barbettes, three forward and one aft, and protected by armored gun-houses, 7 in. and 5 in. thick, which completely enclose the guns; similar protection is given to the four 6-in. guns mounted on the upper deck. The remaining 6-in. guns—making ten in all—are placed on the main deck, within six casemates whose fronts are 6 in. and rears 5 in. thick. The ten 12-pounders and ten 6-pounders are protected by the ordinary shields, three torpedo tubes are also fitted in the stern above water, and two submerged, one on each broadside. All the armament, it need scarcely be stated, has been supplied from Elswick.
Besides the protection to the guns, the O’Higgins has a 7-in. to 5-in. belt, carried along two-thirds of her water-line, of Harveyed armor 7 ft. in depth; this belt is supported on the sloping sides of a complete protective deck, which varies in thickness from in. to 2 in. The conning tower is of 9 in.-armor, and armored tubes are provided for the supply of ammunition to all the guns. The vessel is unusually well fitted in all respects, with electric light and every modern improvement, and is certainly a most powerful addition to the already powerful Chilian navy.—The Engineer.
[England.]
Diadem.
The Diadem has been carrying out a further series of experimental trials, having been required to steam for four hours with a view to ascertaining whether she could, with only 78 per cent, of her boiler heat, obtain the same power as was required of her at her full-power trial on the 26th of January. According to the contract stipulation, she then had to obtain, on eight hours’ run, a mean of 16,500 I. H. P., but, as a fact, the mean obtained was as high as 17,188 I. H. P. Drawing 24 ft. 3 in. forward and 26 ft. 6 in. aft, with 291 lb. of steam in the boilers, and with a vacuum of 27.2 in. starboard and 26.3 port, she, on the 29th of January, worked up to 116.2 revolutions starboard and 115.4 port. The conditions of this trial and the previous ones thus offered some striking differences and similarities, for while on the last occasion the whole of the 30 boilers were in use, on the new trial only 24 were lighted up. The draught of water on each occasion, as well as the vacuum, was about the same; the steam in boilers was 291 lb. at both trials, while at the more exacting test there was a slight reduction in the number of the revolutions—namely, from 119.1 to 116.3. On this occasion, however, forced draught was used for the first time, but the air pressure amounted to only three-tenths of an inch, and the total I. H. P. was 8,168 starboard and 7,693 port, giving a collective I. H. P. of 15,861. This result gave a unit of power for less than two square feet of heating surface, which is the forced-draught surface allowed in cylindrical boilers in the Navy. Contrary to the usual practice at forced-draught trials, the coal consumption was taken, and worked out at the exceedingly low average of 1.95 lb. per I. H.P. per hour, thus further showing a considerable gain by the use of the improved Belleville boilers, while the power was easily maintained. The temperature in the stokeholds and engine room was comparatively low, and there was again a marked absence of dense smoke, flame and clinker from the funnels. The trial fully demonstrated that, should one boiler compartment be disabled in action, the design power of the ship could still be reached, and though the trial was limited to four hours, it was evident that the engines and the ship could have stood the test for a considerably longer period. It was also shown by the result of the trial that in no ship has such high evaporative efficiency been realized from the Belleville boiler. At the thirty hours’ trial with four-fifths of her power some difficulty was experienced in consequence of the frequency with which the fusible plugs were blown out, but after that trial the faces of the plugs were so hammered out that none were blown from their positions during the trial on the 29th, and thus the use of the distillers for the supply of water to make good the loss of steam was obviated. As stated in previous reports, the ship was remarkably steady, no marked vibration being shown at any speed.
On the 6th ult. the cruiser continued her progressive trials in Stokes Bay. She first made four runs over the measured mile at 16 knots, then four runs at 14 knots, and, after swinging for the adjustment of compasses, four runs at 10 knots. In each set of runs the power and speed corresponded with the results that were anticipated from the model trials at Haslar experimental works. The mean of the first set of runs showed that 6,270 I. H.P. gave her a speed of 16,010 with 4,430 I. H. P., and the third set of runs gave a mean speed of 11.07 knots for 1,923 I. H. P. The trial was regarded as highly satisfactory.
On the 8th ult. she left for a further stage of her experimental trials, and anchored at Spithead the next evening. She first steamed for 15 hours with only eight boilers, and with 270 lb. of steam in the boilers and 250 lb. of steam at the engines. At this stage of the trial the revolutions were 64.3 starboard and 65.1 port, while the collective I. H. P. was 3,266. The coal consumption worked out at 2.35 lb. per unit of power per hour, which was in fairly close keeping with her preliminary 30 hours’ trial with the same power, when the consumption was 2.33 lb. During the second phase of the trial, which also lasted IS hours, there were 260 lb. of steam in the boilers, but only iso lb. at the engines. Sixteen boilers, however, were used, and it was found that with 88.9 revolutions starboard and 90.1 revolutions port, and with a collective I. H. P. of 7,119, the coal consumption was 1.94 lb. per unit of power per hour. Both stages of the trial justified the calculations of the Admiralty when the vessel was designed.
The final trial, concluded on the nth ult., was for 30 hours, with only 24 boilers in use, in order to obtain data as to coal consumption. The draught of water forward was 24 ft. 4 in. and aft 26 ft. 9 in. The steam in the boilers was at a pressure of 265 lb. per square inch, the vacuum being 26.3 in. starboard and 25.7 in. port. The mean of the 30 hours gave 106.5 revolutions starboard and 108 port, and the collective I. H. P. was 12,852. The coal consumption worked out at 1.88 lb. per unit of power per hour. In this trial the vessel developed her maximum continuous steaming power with 78 per cent, of her boiler heating surface, and it was obtained under natural draught conditions, but with the fans moving slowly to ventilate the stokeholds. Although the coal was handpicked, so much clinker was formed that after the first four hours of the run it was found necessary to clean out the fires every eight hours, but in spite of this drawback all the required results were obtained with only 2.45 square feet of heating surface per I. H. P. There was very little smoke and no flaming at the funnels. The course taken was from Spithead to Hastings, then a long run to the westward as far as the Scilly Islands, and then back to Spithead. The speed was not officially recorded, but the distance of 215 miles between Beachy Head and the Lizard was travelled in 10 hours 40 minutes, giving a speed of fully 20 knots, thus confirming the data obtained on the official runs between Ram Head and Dodman Point. The vessel has throughout the trials been uniformly successful, and though she has been favored, on the whole, with fine weather, she ran into a stiff breeze and a heavy sea early one morning, when her sea-keeping qualities were well tested, with the most satisfactory results.—Journal of the Royal United Service Institution.
Hermes.
The Fairfield Shipbuilding and Engineering Company, Glasgow, launched, on April 7, 1898, the second class cruiser Hermes, one of two of the same type ordered last spring. The keel was laid down on April 24, so that the vessel, of 5,600 tons displacement, has been launched within a year, notwithstanding the drawback of a fire which destroyed all the machinery and patterns, and delaying the work in the initial stages. This is the second cruiser launched this year, the first having been the n,ooo-ton Argonaut, and in six weeks they will launch a third— the Highflyer; while in the same period they expect to lay the keel of two 12,000-ton armored cruisers, to be called the Cressy and the Aboukir. It may be interesting to compare the Hermes with some earlier second- class cruisers, to show the great progress which has been made under the regime of the present technical advisers of the Admiralty.
[TABLE]
The design of the Hermes in one or two respects introduces improvements on the Venus class, of which the Fairfield Company built two, and of which in all, nine were constructed, the most notable change being in respect of guns and protection. In the Venus there were five 6-in. and six 4.7-in. quick-firing guns, and whereas in the new vessel it has been considered desirable in the interests of uniformity and to secure a larger supply of projectiles to make all the guns of 4.7-in. calibre; these latter fire a 45-lb. instead of a 100-lb. shot; but the difference in energy is not quite so great, the former having a penetration at the muzzle equal to 11.9 in., as compared with 16 in. of wrought iron, but there is a compensating advantage in greater rapidity of fire. In the auxiliary armament there is no change. In the Venus there was an armored cofferdam for the protection of the cylinders; but in the new ships the protective deck is raised to suit this change. The table we have given, however, shows the remarkable advance in second-class cruisers in ten years. The Hermes is 85 ft. longer than the Magicienne, 6 ft. more beam; while the displacement is almost doubled, the draught being increased by 3 ft. 6 in. This difference in weight represents superior qualities in every respect, in armament, in defense, and in radius of action. Some time age we had occasion to compare the Doris with the Latonia class (see Engineering, vol. lxi, page 776), but the ten years’ advance is still more striking.
In the first place, the increased size of the hull gives not only a steadier but a higher freeboard. The guns on the poop and forecastle of the Magicienne were 1 ½ ft. above the water-line; in the Hermes they are 28½ ft. above the load-line forward and 1914 ft. aft. As regards the attack, it will be seen that the new ships are immensely superior. They have eleven 4.7-in. quick-firers, against the six old breech-loaders. Three of the 4.7-in. guns fire ahead in line with the keel, and three fire aft. The guns on either side are built partly on sponsons on the upper deck level, the bow guns having a radius of 6 deg. abaft the beam, and the after guns of 60 deg. forward the beam. The other 4.7-in. weapons are mounted on the broadside with a large arc forward and abaft the beam. These guns are all protected by 4½-in. armored shields. Two of the 12-pounder guns fire forward and two aft, the others being on the broadside, while the most of the 3-pounder guns are in the military tops. As to the supply of ammunition, the Hermes has magazines 58 ft. long in the forward part and 42 ft. aft, in all 100 ft., while in the Magicienne the combined length was only 54 ft-. 28 ft. forward and 26 ft. aft. The increased beam (9 ft.) also adds greatly to the area of the magazines.
As to protection, there is an armored deck extending right fore and aft, curving 5 ft. below the water-line at the sides, and in the center it rises 1 ft. 6 in. above it. This deck ranges from 3 in. to 1½ in. in thickness, covering the whole of the propelling and steering machinery, boilers, magazines, etc. Reserve bunkers are on the protective deck over the machinery space and, whilst affording a water-line belt of coal protection, they give additional security in the event of damage, as they are subdivided into water-tight compartments. An armored conning tower of Harveyized steel is placed forward, fitted up with the usual means of navigating the vessel and directing operations while in action. The whole of the connections with the conning tower are protected by a steel tube extending to the protective deck. The Harveyized armor for the tower was supplied by Messrs. William Beardmore and Co., Glasgow. Bridges are fitted both at the fore and after ends for navigating the vessel under ordinary conditions, with the usual compasses, steering wheels, etc. Three search-lights are operated from these bridges.
As to the hull, it may be said that it is built of Siemens-Martin steel throughout, on the usual principle adopted in warship construction. There is a cellular bottom extending the full length of the engine and boiler spaces, and before and abaft these the water-tight flats of the magazines, etc., continue the double-bottom construction right to the stem and stern. Under the protective deck the side compartments for the full length of the boiler spaces are utilized for stowing coal, the normal capacity being 550 tons, although this quantity may be doubled by carrying fuel on the protective deck, as already indicated. The hull is subdivided by longitudinal and transverse bulkheads into numerous water-tight compartments, the water-tight doors being worked from the main deck as well as from below. The stern-post, struts, stem and rudder are of phosphor-bronze. The stem is of the usual ram form, and the structure behind is especially strong and efficiently connected to the general framework of the vessel, w'ith a view to the contingency of ramming. The rudder is of the balanced type, and controlled by Harfield’s compensating gear below the protective deck. The vessel, being intended for foreign service and long cruises at sea, in which the maintenance of a uniform speed becomes essential, has been completely covered to above the load water-line with teak of a minimum thickness of 3½ in. and coppered. To secure steadiness of gun platform, so necessary in a vessel intended for war purposes, bilge keels 23 in. deep have been fitted for a length of 140 ft.
As to the machinery, it is still more interesting to compare the ship now launched and the predecessors of the same class, the Marathon and Magicienne, built ten years ago, and the Venus and Diana, completed in 1896. The table appended shows the leading dimensions in the respective classes.
[TABLE]
The first striking feature is the increase of steam pressure which has characterized all the ships built during the last four years, and is entirely due to the adoption of the water-tube steam generators. The Hermes has the Belleville boiler fitted with economizers, whereas the Marathon had double-ended multitubular boilers, and the Venus and Diana single-ended multitubular boilers. The result of the increased steam pressure is reflected in the ratio of the volumes of the high- and low-pressure cylinders, which, in the case of the Magicienne, is one to 4.917; in the Venus one to 5.028; and in the Hermes one to 6.81. The Hermes has two low-pressure cylinders to each set of engines, which is now the universal practice in the navy. In the matter of framing and material there has been no important change.
The increase in pressure, and the adoption of water-tube boilers, of course, has had a material influence in the reduction of weight. The total weight of the machinery in the case of the Venus and Diana was 920 tons, and in the case of the Hermes 870 tons; and it will be seen that whereas the Venus only developed 9,600 horse-power under forced- draught conditions, the ship now building will under natural-draught conditions develop a power of 10.000. The reduction in weight is entirely due to the boilers, and notwithstanding the increase of power, the complete boiler installation in the Hermes weighs only 450 tons, against 555 tons in the Venus.
There are 18 Belleville boilers in the Hermes, with nine elements in the “steam generator,” the tubes in this case being, as is usual, of solid-drawn steel, and 4 in. external diameter; while in the economizers there are nine elements, the tubes being 2¾ in. external diameter. The space between the two forms the combustion chamber. In this type of boiler the width of the fire-grate is 8 ft., and the length of the fire-bars is 5 ft. 6 3/8 in. The boilers are arranged in separate compartments, there being six in each boiler-room, arranged athwartships with the tubes running fore and aft; there are three funnels which are carried down to the top of the economizers. In each stokehold there is fitted a Weir’s feed-pump, compressed air blowers for supplying air to the furnaces and combustion chambers, and fans for ventilating the stokehold, but the stokeholds are open. The coal bunkers are arranged on either side of the stokeholds, with an athwartship bunker at the forward end.
Turning now to the engines, it may be said that the cylinders are separate and independent castings bolted together, each fitted with a cast-iron barrel or liner, and arranged for jacketing in all cases. The cylinders and valves are arranged as follows, starting from the forward end: Flat slide valve, low-pressure cylinder, high-pressure cylinder,
piston valve; piston valve, intermediate-pressure cylinder, low-pressure cylinder, flat valve. The two forward cranks work opposite to one another, and are arranged as close to each other as the centers of the cylinders admit. The other pair are similarly arranged, and have the cranks at right angles to the forward cranks. All the valves are controlled by the usual double-eccentric and link-motion gear. In front the cylinders are supported on forged steel columns, while at the back the usual cast-iron A frame is adopted.
The condensers are of brass and placed in the wings, the steam being condensed outside the tubes. The two centrifugal pumps are of gun- metal, and each is worked by an independent engine, but a cross connection has been arranged so that either or both condensers may be supplied with cooling water from either pump. The feed, bilge and hot-well engines are also independent, and an auxiliary condenser is fitted in each engine-room with separate circulating and air-pump for the auxiliary machinery.
The shafting is of forged steel, the cranks being 13 in. in diameter with an 8-in. hole, the line shafting is 12 in. in diameter with an 8-in. hole, and the propeller length is 14¼ in. in diameter with a 9-in. hole. The propellers are of gun-metal, each having three adjustable blades, the diameter being 12 ft. 9 in., and the pitch 13 ft. 6 in., and when running at a speed of 180 revolutions per minute the ship is expected to attain a speed of 19½ knots.—Engineering.
Europa.
H. M. first-class cruiser Europa is one of four vessels which follow, as it were, in the wake of the Powerful and Terrible, of which the Diadem is a type. The two sister ships are the Niobe and the Andromeda. The latter was launched in April last year at Pembroke, the Europa in the previous month at Clydebank, and the Niobe at Barrow on February 20th, so that they all took the water within little over two months. They are all of 11,000 tons displacement, 435 feet long by 69 feet beam, with a draught of 26 feet. They indicate 16,500 horse-power, and are propelled by twin screws. Their boilers are of the Belleville type.
The armament consists of sixteen 6-inch quick-firers, fourteen 12- pounder and twelve 3-pounder guns, and three torpedo tubes, two of which are submerged. The guns are protected by 4½-inch armor, and there is a 4-inch deck armor. The normal coal supply is very large, viz., 1000 tons, and their maximum speed is 20.5 knots. They cost over £560,000 each. There are four other ships in hand very similar to them— the Argonaut, launched at Fairfield in January last; the Amphitrite, being built at Barrow; the Ariadne, at Clydebank; and the Spartiate, at Pembroke. It is expected that these four vessels, which are of the same displacement, will have a greater speed by one-quarter of a knot, gained by running the engines faster.
The Europa left Portsmouth on the 3rd inst. for a thirty hours’ run at 12,500 indicated horse-power, and arrived at Plymouth on Saturday night. She drew 24 feet 6 inches forward and 26 feet 6 inches aft. The steam pressure was 265 pounds, and the vacuum 24.8 inches and 25.5 inches in starboard and port engines respectively. The engines developed 12,379 indicated horse-power and 103.8 revolutions with a coal consumption of 1.94 pounds per unit of power per hour. During the trial she made four runs over the deep-sea course between Rame Head and Dodman Point, when, with 103.6 revolutions and 12,441 indicated horse-power, she realized a speed of 19.331 knots. The Diadem, the pioneer ship of the class, built and engined by the Fairfield Company at Glasgow, at her corresponding trial averaged 19.79 knots over the deep-sea course with a coal consumption of 1.59 pounds per unit of power per hour and 12,776 indicated horse-power. After coaling at Plymouth, the Europa left again on Tuesday morning for an eight hours’ full-power trial, in which she made two runs over the deep-sea course. She had 279 pounds of steam in her boilers, and with 113 revolutions and 17,137 indicated horse-power she achieved a speed of 20.4 knots, but the mean of the eight hours gave a collective indicated horse-power of 17,010. The Diadem at the corresponding trial, with 17,188 indicated horse-power, gave a speed of 20.6 knots on the deep-sea course.—The Engineer.
Furious.
The Furious, cruiser, has completed the second of her coal consumption trials, which was 30 hours at 7003 horse-power. The course was from Start Point to the Scilly Islands, and the runs were made under the best conditions for steaming. The mean results were: Steam at engines, 210 pounds starboard, 210 pounds port; cut-off in high-pressure cylinders, 55 per cent starboard, 54 per cent port; vacuum, 27.8 inches starboard, 27 nches port; revolutions, 127.4 starboard, 128.4 port; mean pressure in cylinders—high, 72.2 pounds starboard, 73.3 pounds port; intermediate, 32 pounds starboard, 37.4 pounds port; low pressure, 15.9 pounds starboard, 14.4 pounds port. The indicated horse-power was—high pressure, 962 starboard and 986 port; intermediate, 1113 starboard and 1312 port; low pressure, 1452 starboard and 1330 port; total, 3527 starboard and 3628 port, making an aggregate horse-power of 7155. The coal consumption' per indicated horse-power was 2.098 pounds, and the average speed 18.7 knots. In coal consumption and speed the trial was exceedingly satisfactory. The next trial will be at 10,000 horse-power.
The third of the series of trials of the cruiser Furious took place at Plymouth. On this occasion the trial was for eight hours at 10,000 horsepower. Com. R. B. Colmore was in charge. The conditions as regards sea and weather were again favorable. The following were the mean results of the eight hours: Steam pressure at boilers, 256 pounds, reduced to 231 pounds in the starboard engine and 236 pounds in the port engine; vacuum 28 inches starboard, 27.1 inches port; revolutions 139.3 starboard, 142.3 port; the indicated horse-power was 5178 starboard, 5094 port—a total of 10,272. The average speed was 20.1 knots, which was satisfactory, being slightly better than that attained by the sister ship Arrogant on a similar trial a few months ago.—Engineering.
The Hogue.
The cruiser Hogue, which has just been ordered from Messrs. Vickers, Sons and Maxim, of Barrow-in-Furness, will, when ready to leave her builders, be sent to Devonport for completion, and to be permanently attached to that command. The Hogue is one of four vessels of the same type recently designed by Sir W. H. White, K. C. B., as an improvement on the Diadem class. She will be armored, and of the following dimensions: Length, 440 feet; breadth, 69 feet 6 inches; mean load draught, 26 feet 3 inches; displacement at load draught, 12,000 tons. She will thus be 5 feet longer and have a displacement of 1000 tons more than the Diadem, whilst she will be 60 feet shorter and of 2200 tons less displacement than the Powerful type of cruiser. The Hogue will have an armament much heavier than that carried by the Diadem, although the number of guns will be less. The armament, as at present arranged, will consist of two 9.2-inch breech-loading guns, twelve 6-inch and seventeen 6-pounder and 3-pounder quick-firing guns, and two submerged Whitehead torpedo tubes. She will be fitted with water-tube boilers and engines of 21,000 indicated horse-power, and is calculated to run at a speed of 21 knots an hour. Her bunkers will be capable of stowing 800 tons of coal, but this can be doubled if necessary by utilizing the wing and other spaces around the engine and boiler-rooms. The vessel will cost, when complete, about .£650,000, of which sum no less than £260,000 will be spent on her by April next. An important feature in her construction will be her armor, this being the first armored cruiser designed since the Orlando type in 1885. Her bottom will be sheathed with wood, the material for which will be prepared at Devonport and sent round to the contractors to be fitted in place.—The Engineer.
Violet.
The new torpedo-boat destroyer Violet has completed her second stipulated three hours’ 30-knot trial at Portsmouth successfully; the vessel encountered a beam wind, but on the whole the weather was favorable; the mean of the six runs on the measured mile showed that with 381 revolutions and 6600 I. H. P. the vessel had a speed of 30.014 knots; the highest speed attained during three hours was 30.8 knots, and the mean of the entire run was 30.16 knots, which was obtained with 381.2 revolutions and 6630 I. H. P.
Flying Fish.
The new torpedo-boat destroyer Flying Fish had her final steam trial at Portsmouth recently, when, with 6454 I. H. P. and 392.5 revolutions,she obtained a mean speed on a three hours’ run of 30.371 knots; the mean of six runs on the mile was a speed of 30.172 knots, with 390.7 revolutions; after the speed trial the vessel tried her steering machinery ahead and astern, both steam and hand gear being tested, and afterwards she had her starting and stopping trials, all of which were satisfactory.
Terrible.
A further sixty hours’ trial of the Terrible, first-class cruiser, was made on the 25th, 26th, 27th and 28th of last month, during her voyage from Portsmouth to Gibraltar, at two-fifths authorized natural draught power. A start was made off St. Catherine’s at 2.30 P. M. on May 25th, and terminated at 10.30 A. M. on May 28th, after completion of which the ship was kept running at the same power until she reached Gibraltar in sixty- eight hours. The results, which are pronounced very satisfactory, are given in the accompanying statement:
Report of a 60 Hours' Trial of H. M. S. Terrible at 10,000 I. H. P.
Draught of water.......................... Forward 28 ft. 2 in. Aft 29 ft. 5 in.
Steam in boilers = 230 lb. Starboard. Port.
Vacuum....................................................... 26.6 in. 26.5 in.
Revolutions per minute................................. 81.1........ 81.42
Cut-off in H. P. cylinder, percentage of stroke....36.4 31.7
Mean pressure—High................................... 49.29 57-38
Intermediate............................................... 23.77 22.14
1st low............................................. 9.48 9.50
2nd low............................................ 9-49 9.22
Indicated horse-power—High..................... 1568.9 1825.8
Intermediate............................................. 1798.8 1682.5
1st low....................................................... 846.5 850.9
2nd low...................................................... 847.0 825.9
5061.2 5185.1
Total power.............................................. .....10,246.3
Total distance run............................................ 1020 knots.
The average speed of the vessel was seventeen knots, and the coal consumption per indicated horsepower per hour for all purposes 1.89 pounds, whilst the gross total indicated horse-power developed was 10,246.3.—The Engineer.
Ariadne.
The Clydebank Engineering and Shipbuilding Company, Limited, Glasgow, launched on April 22nd the Ariadne, a first-class cruiser of practically the type of the Europa, which was delivered for trial to the Admiralty a few days ago, and is now being prepared at Portsmouth for sea. The Ariadne is 462 feet 6 inches over all, and 435 feet between perpendiculars; her beam, extreme, is 69 feet, and her displacement 11,000 tons. There is a double bottom the full length of the machinery and boiler spaces, and, fore and aft, steel water-tight magazine flats continue the protection. Above the protective deck over the boiler spaces, and below alongside the boilers, are side compartments for the stowage of coal; and with the cross bunkers there is formed as complete a protection as is possible to the boilers. At the normal draught the coal capacity is 1000 tons, but there is provision for double that quantity of fuel should the necessity of carrying it arise. The subdivision of the hull by longitudinal and transverse bulkheads is exceptionally complete, and with so many water-tight compartments the vessel is as nearly unsinkable as a warship may be. In the bulkheads openings have been cut only where they are likely to be absolutely necessary, and the water-tight doors which have been fitted may be worked both on the spot and from the main deck. As is usual in warships that are sheathed, the stem, stern post and shaft brackets are of phosphor-bronze. The hull, up to about 6 feet over the water-line, is sheathed with teak planking, which, when the Dockyard takes the vessel over, will be coppered. There are bilge keels about 210 feet long and 3 feet deep. The rudder is a casting of phosphor-bronze plated with naval brass, and may be worked either by screw-steering gear actuated by duplicate engines, one in each engine-room, or by hand. All the steering apparatus is below the protective deck, which has a thickness ranging from 4 inches amidships to 2½ inches at the ends, extends the whole length of the vessel, and covers completely the machinery, boilers and magazines. The conning tower is of Harveyed steel, and the steering gear, shafting, voice tubes, etc., are protected as far as the protective deck by a steel tube 7 inches thick. The navigating bridges are as in other ships of the navy, but in the Ariadne the after one is higher, in order that the view of officers may not be obstructed by other deck erections and fittings. When the vessel is completed her armament will be: Four 6-inch quick-firing guns with shields—two on the upper deck aft and two on the forecastle deck; twelve 6-inch quick-firing guns in armor casements of Harveyed steel—eight on the main deck and four on the upper deck; fourteen 12-pounders and a large number of smaller and machine guns. There will also be two torpedo tubes, discharging under water forward. The complement of the vessel is about 700 officers and men, and, in addition to the accommodation for them, there is a suite of rooms for an admiral. The machinery consists of two sets of tripleexpansion engines fitted in two water-tight compartments; each set has four inverted cylinders working on four cranks. The high-pressure cylinder is 34 inches in diameter, the intermediate 55½ inches in diameter, and each of the low-pressure 64 inches in diameter. All are adapted for a stroke of 4 feet. The cylinder covers are of cast steel, and the pistons, of conical shape, are also of cast steel. The high and intermediate cylinders are fitted with piston valves, and the low-pressure with treble- ported slide valves, with a relieving ring at the back, all the valves being worked by the usual double-eccentric and link-motion gear. Reversing is effected by means of double-cylinder steam engines, with gear of the all-round type, hand-gear also being available. The sole plates are of cast steel, and the cylinders are supported by cast-iron columns at the back, and forged-steel columns at the front. The main condensers are at the back of the engines, and constructed of cast brass in oval form; they are fitted with brass tubes 5/8 inch in diameter. The condensing water is supplied by four centrifugal pumps of gun metal, fitted with independent engines. Steam will be supplied by 30 water-tube boilers and economizers. The boilers are arranged in four groups, each group fitted in a water-tight compartment. They are designed to work at 300 pounds pressure, reducing valves being fitted to reduce the steam pressure to 250 pounds at the engines.—Engineering.
Goliath.
On March 23rd the first-class battle-ship Goliath, the first keel plate of which was laid on January 4th, 1897, was launched at Chatham. The Goliath is 390 feet long between perpendiculars, has an extreme breadth of 74 feet, and a mean draught of 26 feet, and her displacement will be about 13,000 tons. This draught gives her a freeboard of 22 feet 6 inches forward, 19 feet amidships, and 19 feet aft. The side protection extends for 196 feet of the middle of her length, and from 5 feet below the waterline to 9 feet above it, the armor plating being of Harveyized steel 6 inches thick, while a belt of 2-inch nickel-steel armor runs right away in a broad streak along the water-line from the citadel to the stem and protects a width varying from 12 feet 6 inches to that of the whole depth of the stem below the main deck. This 2-inch, or 2½-inch, belt, including the skin plating of the ship, represents at least 6 inches of ordinary wrought-iron armor, and will constitute a formidable obstacle to projectiles from small Q. F. guns and is sufficient to burst common shell from guns of large calibre. The bow plating of the Goliath has, however, a very important duty to fulfill, independent of that of meeting the attack of small quick-firers. She has a cigar-shaped snout, and is supported internally by the 2-inch steel-armored deck and the elongated stiffening plate below, the breast hooks lending similar aid near the water-line. In the Resolution all these features are also found, but they are only held together by the steel framing of the ship and by the ordinary skin of 20-pound steel plates. The Goliath, on the other hand, has a double wall of nickel steel supporting the framing, 4 inches in combined thickness, and from 30 feet to 35 feet in depth. This could not possibly be turned aside by impact with the hull of an enemy, but would enter it like a cold chisel, and, after ripping open the plates, its very shape would facilitate the withdrawal of the ram uninjured. The filling in of the 3-foot spaced bulkheads with cork is also an additional safeguard, for it makes the stem a solid but elastic feature right back to the main collision bulkhead. The hollow stems of earlier vessels were always a source of possible danger. Then, again, in the ship now under consideration the doublebottom system is carried forward to the very forefoot itself. The longitudinals of the bracket framing are extended by intercostal portions to frames immediately behind the stem casting, thus preventing any working of the structure or of the armor plates covering it. At both ends of the armor belt rounded armor bulkheads are fitted of the same material, 12 inches, 10 inches, 8 inches and 6 inches thick. The barbettes at the forward ends of the battery are circular in plan, and are armored with Harveyized steel, the upper tier of plates being 12 inches and the lower 6 inches thick. The conning towers are circular in form, and both are 9 feet 6 inches thick. From the base of each tower a forged steel communicator tube of 4 inches internal diameter descends, the thickness of the forward one being 8 inches and of the after one 3 inches, inside of which are led the controlling shafts of the steering engines, engine-room, telegraph rods, and all the important voice tubes. The protective deck between the armored bulkhead is made of two thickness of half-inch steel plates, with additional 1-inch plates on the sloping sides. Beyond the limits of the side armor are a lower deck, protected by two thickness of i-inch plates. The armament of the ship will consist of four breechloading 12-inch 46-ton guns, on turntables, in circular redoubts, with all- around loading mountings, made by Messrs. Whitworth & Co., and they will be protected by shields, having 8-inch Harveyized steel in front, sides and rear, the floor plates being of 2-inch nickel steel and the crown plates of 2-inch mild steel. There are also twelve 6-inch Q. F. guns, eight being in 6-inch casemates on the main deck, while four are similarly protected on the upper deck. The four end main-deck casemates have novel features, in that the guns can fire right forward and right aft respectively. Of ten 12-pounders (12-cwt.), six are placed on the upper deck amidship and four on the main deck fore and aft. Each of the fighting tops of the ship is armed with three 3-pounder Hotchkiss guns, the shelter deck forward with two 12-pounder boat and field guns, and the shelter deck aft, on the boat deck and bridges, with eight Maxim guns and six Howitzer guns. The ship is also fitted with four submerged tubes for 18-inch torpedoes, two on the broadsides forward and two aft. She will carry fourteen 18-inch and five 14-inch torpedoes, these latter for firing with dropping gear from the ship’s steamboats.
The propelling machinery of the Goliath, which has been constructed by Messrs. Penn and Sons, of Greenwich, are of the vertical inverted expansion type, the cylinders being 30 inches, 49 inches and 80 inches in diameter respectively, and 4 feet 3 inches stroke. The main and auxiliary condensers in each engine-room are of brass. There are also in the engine-rooms two evaporators and distillers, four fire and bilge engines, four main centrifugal pumps, two hot-well pumps, one drain tank pump, two dynamos and engines. Three main and three auxiliary feed pumps are in the boiler-rooms. The ship is also fitted with two refrigerating machines, capable of reducing the temperature of a chamber of 1800 cubic feet capacity to 15° Fahr. after 12 hours working. Six search-lights are carried, one on the platform high up on each mast and two on each of the bridges. There are six positions for steering by steam, viz., forebridge, both conning towers, tower deck forward, and in both steering compartments. There are twin screws, 17 feet in diameter, and arranged so that the pitch can be varied. The I. H. P. of the engines is to be 13,500; speed of ship, 18½ knots. The ship carries 16 boats.—Journal of the Royal United Service Gazette.
Woodlark.
The official two hours’ trial of the Woodlark, one of the shallow- draught armed river steamers recently ordered by the British Government, has lately taken place on the Thames. The vessel, which has been built by Messrs. John I. Thornycroft & Co., is 145 feet long and 24 feet broad. The draught of water was not to exceed 2 feet when loaded with 30 tons dead weight, and the speed under these conditions was to be 15 miles per hour. The mean draught of water on trial was found to be 1 foot 11½ inches, and the vessel covered 30¾ statute miles in two hours. She is armed with Q. F. and Maxim guns, and the sides above the waterline and the deck in the wake of the machinery are protected with Cam- mell’s bullet-proof steel plating. The Woodlark is fitted with Thorny- croft’s twin screw-turbine propellers in raised tunnels, and is the fastest of the gunboats of this class hitherto constructed. Her speed astern was found to be 4.34 miles per hour, and she proved to be under control when going astern.—Journal of the Royal United Service Institution.
Angler.
The official trials of the Angler, torpedo-boat destroyer, were reported at Chatham on Saturday, April 14th inst., as follow: Speed of ship, 29.879 knots; steam pressure in boilers, 212 pounds per square inch; air pressure in stokeholds, 3.4 inches; vacuum in condensers, 25.7 starboard, 24.8 port; revolutions per minute, 396.2 starboard, 388.6 port; mean indicated horsepower, 3003 starboard, 2859 port—total, 5862. The consumption of coal per indicated horse-power per hour has not yet been worked out.— Engineering.
Wolf.
H. M. S. Wolf has completed her official full-power speed trials on the Clyde, in the presence of the Admiralty representatives. Six runs were made on the measured mile with the following results:
Steam. Time. Speed, lb. min. secs. knots.
First mile..................................... 211 1 58 1/5 30.46
Second mile................................... 212.... 1 56 1/5 30.98
Third mile...................................... 222.... 1 55 1/5 31.25
Fourth mile.................................... 215.... 1 54 3/5 31.41
Fifth mile........................................ 223.... 1 55 1/5 31.25
Sixth mile....................................... 208.... 1 55 3/5 31.14
The mean speed thus realized was 31.2 knots. After completing the six miles the vessel was taken outside the Cumbrae to complete the three hours’ steaming at her contract speed of 30 knots, which was easily obtained, the results at the finish showing a speed of considerably over a quarter of a knot in excess of the contract. After completion of this trial, the usual steering trials at full speed ahead and astern were carried out, and the stopping, starting and reversing of the engines demonstrated for efficiency. The Wolf is the tenth 30-knot destroyer that Messrs. Laird have now completed for the British Admiralty.—Engineering.
Powerful.
Various and numerous inaccurate statements concerning the performance of the Powerful on her voyage to China have been diligently put in circulation by those who can find no good thing in her. One writer went so far as to say that the port engines will have to be lifted out of her and almost rebuilt. Last week we gave an explicit contradiction to those rumors. Mr. Allan, M. P. for Gateshead, did excellent service on Monday night by putting certain questions about the ship to Mr. Goschen. As far as construction is concerned the replies made by the First Lord of the Admiralty were quite satisfactory. There had been some heating of bearings in the course of a steam trial after leaving Mauritius—we gather that the white metal ran and had to be replaced. For five days the ship ran under easy steam with one screw until the bearings had been re-lined, and since, there has been no trouble. So far so well, but the consumption of coal seems to be very heavy. She had 2800 tons on board when leaving Portsmouth, at Las Palmas she took in 800 tons, at the Cape 2286 tons, at Mauritius 800 tons, at Colombo 2115 tons—or a total of 8300 tons, costing no less than £11,000. We do not know what power she exerted, nor what was her steaming time, all that will come out by- and-by, no doubt; but the figures given work out with rather remarkable results as compared with her trial trip performance. This it is known that the ship can steam 14 knots for about 5000 indicated horse-power. At 2 pounds per horse per hour, this gives us per day, say, no tons; this, divided into 8000 tons, gives us, in round numbers, 72 steaming days of 336 miles per day, or, in all, over 24,000 miles—or more than round the world. This apparently shows that she burns much more than 2 pounds per horse per hour, even after due allowance has been made for auxiliary engines.
Gun and Steam Trials of H. M. S. Illustrious.
H. M. S. Illustrious, a battle-ship of the Majestic class, has completed her trials, and is preparing for commission. The results of the gunnery trials mark a very pronounced step in advance, for as a consequence of the introduction of many mechanical devices, the 12-inch 46-ton breechloading guns were fired with a rapidity which almost justifies their being classed as quick-firing weapons. The guns are of the ordinary service type, firing an 850-pound projectile at a muzzle velocity of 2367 foot- seconds, equal to an energy of 33,020 foot-tons; and yet so complete is the operative mechanism that the only manual effort involved is the lifting of the charge in halves, each weighing 83 pounds, from the pockets in the loading hoist on to the loading tray. The two guns in the after turret were fired three times in 107 seconds from the first discharge to the last; the time between the second and third rounds was only 49 seconds, and this was accomplished by the ordinary crew from H. M. S. Excellent after only two or three days’ practice. Doubtless, the ship’s own company, when they get accustomed to the work, will improve upon this performance; but, as it is, it means that from the forward and after turret, trained on the enemy, 10,200 pounds of shot can be delivered in 107 seconds, and there is no reason why this rate should not be continued. This, when the energy (396,240 foot-tons) is noted, constitutes a vigorous attack which no ship could survive. While the gun and turret mechanism was designed by the late firm of Sir Joseph Whitworth & Co., at the Openshaw Works, prior to the amalgamation with the Armstrong Company, there is a certain appropriateness in the association of this advance in progress with the name of Armstrong, for it was Lord Armstrong who advocated and introduced the rapid-firing type of gun into naval warfare for guns of lighter calibre. Its immense importance was fully demonstrated during the recent conflict between China and Japan, and now the united firms have attained a like result with guns of large calibre, for, considering the weight of gun and ammunition, the rate of fire attained on these trials may, as we have said, be classed as “quick firing.”
As we have said, the 12-inch guns of the Illustrious are similar to those in the other ships of the class—of 46 tons, wire-wound, and of Woolwich pattern, with the Woolwich hand-breech mechanism, which latter differs from the type previously employed. The older breech-loading guns, it will be remembered, had a mechanism with two distinct operations—the rotating of the screw plug by a Stanhope lever, and its withdrawal by the operation of a crank handle which first drew the plug to the rear, and afterwards swung the block and carrier ring about the axis pin, clear of the box. The new mechanism has a continuous motion operated by a handwheel, and effects the same functions as the old gear, but in a much shorter time; about 8 seconds when the gun is about the horizontal position, but a longer time is taken when the gun is being run in or out at the same time, or is at elevation.
Two guns of this type are fitted en barbette forward and two aft, both with armored protecting hoods, and the mountings for the Illustrious, as well as those for the Caesar, were supplied from the Openshaw Works. They resemble in general idea the mountings fitted to the Barfleur, Centurion, and Renown, and fully described in Engineering,[5] but many modifications have been introduced, and to these special reference may here be directed. The Centurion class carried 10-inch guns, and the operations of loading, etc., were performed primarily by hand gear, whereas in the new ships hydraulic power is used, the weights to be dealt with, both in respect of gun and ammunition being considerably heavier. The point of similarity between the two types of ships is that the shell chamber is carried underneath the gun platform, as described in our article on the Barfleur’s gun mounting. The “ready supply” of ammunition is carried in this shell chamber and conducted directly to the loading position by hoists, so that the essential principle of all-round fire and loading at any position of training is maintained. In the Centurion class the weapon was balanced about its trunnions; but in the new ships, with the heavier ordnance, the gun and slide are balanced about the trunnions of the slide, so that the effort of elevating is minimized, a necessity in the case where the hand gear has to be resorted to in the event of any mishap to the hydraulic mechanism. The whole system of mounting, too, is balanced about its centre of rotation to meet the same desideratum. The centre of gravity coincides as nearly as possible with the centre of rotation, so that any heeling of the ship, permanently or temporarily, does not affect the force to be exerted in training the gun.
The powder is carried, as usual, in the magazines, from whence it is brought to the shell chamber by hoists working in a fixed central tube. Other hoists in the same tube bring shell, should the supply in the shell chamber become exhausted. The powder and shells thus brought up the central tube are transferred, as in the case of the ships of the Centurion class, to the hoists in the rear of the guns, which hoists act as loading trays when in their proper position. But in the case of the Illustrious the hoists are operated by hydraulic power instead of by hand or electrical power. The transport of shell in the shell chamber is also effected by two hydraulic power cranes, which transfer the shell from the bins or pockets and deposit them upon the loading trays on the upper hoists. The charges brought up at the last moment through the central tube are of sufficiently small weight to be readily handled and quickly transferred to powder pockets in the loading hoists, from which hydraulic rammers on the turntable push the shell and charge into the gun. In the event of the whole hydraulic system being disabled, the guns can still be loaded by hand power, an upper loading position and loading tray being provided for each gun within the hood, and simple means are adopted for hauling the shell from the shell chamber, or the magazine, to this upper loading position, when, as in the case of the Centurion class, they can be pushed into the gun by hand rammers.
The rotation of the turret is effected by hydraulic turning engines, so arranged that when the hydraulic power is cut off from the engine, a powerful brake holds the turning mechanism and prevents further rotation. On the gun platform is an auxiliary hand pump, which can be operated by the gun’s crew and thus run the gun in and out, elevate the gun, or open the breech, to which the hydraulic mechanism is applied. The brake system for controlling the recoil of the gun is independent of the run in and out system; the brakes are self-contained and control the recoil very much in the same way as in an ordinary hydraulic recoil mounting, while the run in and out system is connected with the service pressure from the main pumping engines, and serves for manoeuvring the gun on its slide in either direction, or this may be done by hand gear, but much more slowly. In this connection it may be stated that the slight break-down in the case of the Caesar a few weeks ago, about which so much was made in the daily press, was not in connection with the general design of the mounting at all. The Caesar had long since successfully passed through her gunnery trials, but on the occasion of the commissioning trials in January, it was decided to try experimentally a new form of valve on the run-out cylinder, but this proved unsatisfactory. The valve fitted on the Illustrious differs from the form experimentally tried; and, indeed, the Caesar was fitted with the same valve as the Illustrious with equally good results.
In addition to the hand gear for the breech mechanism, hydraulic gear is fitted, the hand gear being arranged so that it can be disconnected. The hydraulic is more rapid in its operation; the breech can be opened or closed when the gun is at its maximum elevation—13½ deg.—in 5 seconds. Not only so, but the operation of opening or closing can proceed during the period when the gun is being brought to the loading or firing position, which effects a saving in time in the manipulation of the gun. In effect these hydraulic operations render the 12-inch gun with its high ballistic qualities a quick-firing weapon; no effort being involved on the part of the gunner, except in the pulling of the levers, admitting water pressure to the rams operating the mechanism. The control of the mounting is effected, as usual, from two sighting stations, one on each side, to which positions are, brought the various levers and handwheels for training and elevating the guns, as well as the automatic sights. The operating levers for controlling the hoists, rammer and running in and out of the gun are conveniently placed in rear of the sighting station of the gun platform within the view and control of the captain of the turret. Auxiliary elevating levers are also provided on the gun platform, and there is a complete duplicate service of hydraulic pressure pipes in addition to the usual central pivot supply.
At the official trials last week several rounds were fired first from the guns in the fore barbette, to test the effect on the decks of the ship. The first shot was fired from the right gun at 80 deg. before the beam, with an elevation of 1½ deg. The left gun was next fired with a reduced charge on the same bearings. In the third round the right gun fired a reduced charge with ½ deg. elevation, and in the fourth round the left gun fired a full charge at 1½ deg. elevation. The fifth and sixth rounds were fired right ahead with about ½ deg. of elevation, and as it was found that no material damage was done to the decks, further trials on this score were deemed unnecessary. The two guns were next fired with the hand gear alone in use, both guns being fired simultaneously, the left gun at extreme depression and the other at extreme elevation. The object of the trials of the two after guns was to determine the time required, and in this respect an unparalleled record was made. The guns were fired simultaneously, and the time which elapsed from the firing of the first to the discharge of the third round was 107 seconds, during which six shots of 850 pounds were fired. For guns of such calibre this may be regarded as extraordinary, and is a speed which has never been approached in any navy. The time between the second and third rounds was 49 seconds, and these results, as we have already stated, were obtained with an ordinary crew from H. M. S. Excellent after a few days’ drill. It must be borne in mind too, that with this all-round system of loading, the gun, once it has been trained, can be kept on the enemy during the whole operation of loading, and therefore no time is lost in bringing to “bearing” between each discharge, so that for all practical purposes the rapidity of fire on trial was under conditions of warfare. The loading, too, was done with the gun at an elevation of 13½ deg. Representatives were present from both Elswick and Openshaw on behalf of the contractors, and the trials, it may be added, have given great satisfaction to the authorities and all concerned.
[TABLE]
Prior to the gun trials the Illustrious completed her steaming trials in the English Channel and North Sea; these were somewhat protracted owing to difficulties experienced with the Martin’s system of induced draught fitted. The engines were constructed by Messrs. Penn & Sons, Greenwich, who were represented by Mr. J. Dixon, to whom we offer our congratulations on his appointment as manager at Messrs. Penn’s. The engines are of the triple-expansion type, with cylinders 40 inches, 59 inches and 88 inches in diameter by 4 feet 3 inches stroke, and were designed to develop 10,000 indicated horse-power on an eight hours’ natural draught trial, and 12,000 indicated horse-power on an induced- draught trial of four hours’ duration. The designed speed for the former power was 16½ knots, and for the latter17½ knots, which has easily been realized with other ships of the same class, so that there was no need to ascertain the speed on this occasion. The twin propellers have four blades, the diameter being 16 feet 11¾ inches and the mean pitch 19 feet 9 3/8 inches. The results on the three trials are given in the table above.
The New Armored Cruisers.
The Admiralty have this week given out the orders for the four armored cruisers which it was decided to build in July of last year, when the treasury made a supplementary grant to the Navy. Messrs. Vickers, Sons and Maxim, Limited, will build one of these vessels at Barrow-in- Furness, the Fairfield Shipbuilding and Engineering Company, Limited, will construct two, and the Clydebank Company, Limited, have been given the contract for the fourth.
The new vessels differ from the eight ships of the Diadem and Ariadne classes in having a side armor for the greater part of the length, and as more powerful machinery is arranged for, the speed will be greater. Their armament, too, will be the same as in the Powerful and Terrible, so that while intended for cruisers they almost rank as battle-ships, and will be able to take a place in the line of battle. The cost, completed, including guns, will work out to about 630,000l., while the Powerful and Terrible cost 750,000l., and the Diadem class an average of about 575,000l.; so that in view of the superior qualities over the latter, especially in respect of protection and speed, it will be recognized that Sir William White and Sir John Durston, the two technical officers chiefly responsible, have arranged a type of ship which will not only be efficient, but represent good value for the taxpayer’s money, a point never forgotten at the Admiralty. The following table gives a comparison between the three latest types of modern cruisers:
— | “Cressy” Class. | “Ariadne” Class | “Powerful" Class. |
Length, between perpendiculars | 440 ft. | 435 ft. | 500 ft. |
Beam | 69 ft. 6 in. | 69 ft. | 71 ft. |
Draught | 26 ft. 3 in. | 25 ft. 3 in. | 27 ft. |
Weight of hull | 7860 | 6975 | 8480 |
Displacement | 12,000 | 11,000 | 14,200 |
Side Armor | 6 in. | — | — |
Casemates | 6 in. | 6 in. | 6 in. |
Protective deck | 3 in. and 2 in. | 4 in. and 2½ in. | 4 in. |
Armament | Two 9.2-in. B-L.; | Sixteen 6-inch | Two 9.2-in. B-L.; |
Indicated horse-power | 21,000 | 18,000 | 25,000 |
Speed | 21 | 20$ | 22 |
Normal coal capacity[6] | 800 | IOOO | 1500 |
The details of construction are similar in all three types—double-bottom cellular system with longitudinal frames, extending up to the protective deck, or 5 feet below load line, to which the protective deck is connected, and on which the side armor in the Cressy class is constructed, as in all our battle-ships. This double construction gives a great security to the ship. All the ships are sheathed with teak 4 inches thick and coppered.
The armor belt extends for about 230 feet of the length of the ship, and is 240 pounds thick with 4 inches of backing. This belt is 11 feet 6 inches deep, extending 5 feet below and 6 feet 6 inches above the load line, the ordinary shell plating above that being 22½ pounds thick; but as in previous cruisers, all the 6-inch guns are within 6-inch armored casemates. The belt extends to within 120 feet of the stem and 90 feet of the stern, and there extends athwart the ship a bulkhead of 200 pounds in thickness. And here it may be said that all the armor is of nickel steel hardened by the new process, which gives a resistance to penetration by projectiles quite double that possible six or seven years ago, so that the 6-inch armor here is far superior to the 10-inch armor in some comparatively recent ships. The side armor does not, as in all previous ships, terminate at the bulkheads; but is continued, although of less thickness, right to the ram, as in the new battle-ships of the Canopus class. This is of 2-inch nickel steel in addition to the shell plating, so that at least all explosive shells will be kept out of the ship. At the stern, abaft the armored bulkhead, the shell plating is greatly increased in thickness, and the protective deck reinforced with the same object in view. Here the protective deck is 80 pounds thick; whereas within the citadel, formed by the side armor and bulkheads, it is 60 pounds. The main deck is also of more than usual thickness—40 pounds—to assist in protection; while, as usual, the coal bunkers are arranged on either side, from all of which it will be appreciated that while giving adequate weight for a high speed, and without relinquishing one jot or title of the elements of strength, the director of naval construction has given a protection equal to our latest battle-ships and superior to nearly all preceding ships. As to the arrangement of decks—protective, lower, main, upper and boat deck—the vessels are all alike; the Powerful and Terrible only have poops.
The main armament consists of two 9.2-inch 22-ton breech-loading guns, each mounted in barbettes, with 240-pound nickel steel hardened, and with a gun shield of 6 inches thickness. These barbettes are within the armored bulkheads, and the 12-inch conning tower, with 3-inch armored communication tubes, is further aft. There are two bridges and two conning towers, one forward and the other aft. These main guns have an arc of training of 135 deg., and will probably have an angle of elevation of 13 deg. For bow fire there is on the main deck a 6-inch gun on either side, and above, on the upper deck, on either side of the forecastle another, so that four 6-inch guns fire in line of the keel to 28 deg. abaft the beam. The 9.2-inch gun aft is on the upper deck—there being no poop, while four 6-inch guns also fire astern to 28 deg. forward of the beam. There are two 6-inch guns firing on either broadside with an arc of 120 deg. In addition, there will be twelve 12-pounder guns, two of which augment the bow fire and two fire astern. There are five other machine guns. There are two masts, but the tops only carry search-lights.
The appearance of the ships will be pretty much the same as that of the Diadem, with four funnels for the four boiler-rooms, each of which is 32 feet 6 inches long, the three after being 44 feet broad with two rows of four boilers, and the forward compartment 34 feet broad with two rows of three boilers. This is practically the same as in the Diadem, and here also special attention has been paid to ventilation, a large number of fans being provided with electric motors.
As to the machinery, the following dimensions may be tabulated:
— | “Cressy” Class. | “Ariadne” Class. | [7]“Powerful” Class. |
High-pressure cylinder... in. | 36 | 34 | 45 |
Intermediate-pressure cylinder.. “ | 59 | 55½ | 70 |
Low-pressure cylinder | 68 | 64 | 76 |
Low-pressure cylinder.... “ | 68 | 64 | 76 |
Stroke | 48 | 48 | 48 |
Revolutions | 120 | 120 | 120 |
Indicated horse-power | 21,000 | 18,000 | 25,000 |
Number of Belleville boilers | 30 | 30 | 48 |
Heating surface........... sq. ft. | 51,500 | 45,900 | 69,453 |
Grate area................... “ | 1,650 | 1.449 | 2,192 |
Pressure at boilers...... lb. | 300 | 300 | 260 |
Pressure at engines..... “ | 250 | 250 | 210 |
Weight of machinery.... tons | 1800 | 1550 | 2250 |
Indicated horse-power per ton | 11.61 | 11.8 | 11.11 |
Square feet of heating surface per indicated horse-power | 2.45 | z-55 | 2.77 |
Indicated horse-power per square foot of grate | 12.7 | 12.4 | 11.40 |
The engines are, as in previous cases, to be of the inverted direct- acting type, each set having one high, one intermediate, and two low- pressure cylinders. In the Cressy class one of the low-pressure cylinders is to be placed forward of the high-pressure and the other aft of the intermediate cylinder. The crankshaft will be in two interchangeable parts, each part having two cranks placed directly opposite. The Yarrow- Schlick-Tweedy system is to be adopted in some of the ships. The propellers work inwards, and the starting platform is to be at the centre of the ship. The cylinders will be supported in the front by wrought- steel pillars, the back columns will be cast iron, connected together at the top with suitable tie-plates. The frames for the main bearings will be of cast steel tied together, each set of engines being independent of each other. The valves of the high-pressure and intermediate cylinders will be of the piston type, one to each cylinder. Those for the low- pressure will be of the double-ported flat form (one to each cylinder), with a relief ring at the back. All the valves will be actuated by means of double eccentrics and link motion, separate provision being made for adjusting the cut-off in each cylinder. The valve setting will be arranged so that the power developed by the two low-pressure cylinders combined shall equal that of the high or intermediate cylinders.
Each set of main engines will have one vertical air pump worked by means of links and levers from the high-pressure crosshead. The main condensers are to have a total cooling surface of 21,000 square inches. The two auxiliary condensers will have 3000 square feet of heating surface. There will be four circulating pumps with 48-inch impellers, the duty being 1400 tons from the bilges per hour.
The crankshafts are to be of 19 inches external diameter with a 10-inch hole, the crankpins of 21 inches external diameter with 12-inch hole, those for the high-pressure and intermediate-pressure engines being 24 inches long, and for the low-pressure, 16 inches. The main bearings are to have a total length of about 14 feet, and the thrust surface will be 2500 square inches. The propeller shaft is to be 19½ inches external diameter, with a 10½-inch hole. The propellers are to be about 18 feet in diameter.
As indicated in the table, there will be 30 boilers of the Belleville type with economizer; the heating surface in the steam-generating tubes will he 33,500 square feet and in the economizer small tubes 18,000 square feet, a total of 51,500 square feet; the grate surface being 1650 feet. The tubes will be solid drawn, 4½ inches external diameter for the generators and 2¾ inches for the economizers. The fans for the stokehold will be of the double-breasted type; 12 of them will be 6 feet 6 inches in diameter and four of them 6 feet in diameter. The two pumps for the hot well will be of the crankshaft type, while there will be eight feed pumps. The capacity provided for feed water is 116 tons. The grease extractor will have 15,750 square inches of filtering area. There will be four fire and bilge pumps having a duty of 100 tons per hour.
Of the other auxiliary machinery, it may be said that there will be four evaporators of 108 tons capacity, two distillers of 54 tons capacity, three electric-light generators, two steering engines, two sets of air-compressing pumps and four reservoirs, two boat hoists, two refrigerating engines of the cold air type, coal hoists, ash hoists, etc., as usual.—Engineering.
Official Speed Trials of War-Ships.
An official return shows the speed trials of warships. Of torpedo destroyers, fifteen have passed successfully through the trials during the past year, one of them being a 27-knot boat, while the others are 30-knot design. Messrs. Laird, of Birkenhead, and Messrs. Palmer, of Jarrow-on-tyne, appear on the list for five boats each, Thornycroft for three, and the Fairfield Company for the fifteenth 30-knot boat. In each case the boats had to run for three hours for speed, and again for three hours at full speed to ascertain the consumption of coal, and it was a condition that should the average rate of consumption exceed 2.5 pounds I. H. P. per hour an extra load would have to be carried in the speed trial, this extra load to be equivalent to the excess in consumption over a given period. Only five out of the fifteen boats seem to have come within the 2½ pounds, the highest rate of consumption having been 2.77 pounds, in the case of one of Palmer’s boats; but it is difficult to understand how in the case of Thornycroft’s three boats there should be such variation as 2.08 pounds in one case, 2.2 pounds in another, and nearly 2.6 pounds in the third, when all three boats, engines and boilers were the same. The difference is equal to over 1¼ tons per hour, and it is probably attributable only to the stoking. Laird’s boats’ consumption varies less, between 2.41 and 2.53 pounds per I. II. P., while Palmer’s varies between 2.42 and 2.76 pounds. The Fairfield Company’s Osprey appears as burning 2.58 pounds per I. H. P. per hour. As to power, this necessarily would be affected by weather, etc., but there are also wide variations. The highest is 6606 I. H. P. for 30.142 knots in the case of Laird’s boat, the Panther, but Fairfield is not far behind with 6588 I. H. P., but for this she has the best speed on the list. One or two of the boats, especially those of Thornycroft, got their speed for less than 6000 I. H. P., but for this she has the best speed on the list; the lowest was 5654 I. H. P. for 30.184 knots. Messrs. Lairds boats range about 6000 to 6200, with the exception already given. The highest speed was got with the Fair- field boat, which made 30.674 knots when developing 6588 I. H. P., and on another trial 30.427 knots for 6412 I. H. P. So that the high power was in their case well justified by events. Palmer’s Chamois comes next with 30.396 knots for 6265 I. H. P.
Ships Under Construction.
The following vessels will be under construction or completing during 1898-99: 12 battle-ships, 16 first-class cruisers, 10 third-class cruisers, 6 second-class cruisers, 10 third-class cruisers, sloops, 4 twin-screw gunboat destroyers.
[France.]
Amiral de Gueydon.
The dimensions of the new first-class armored cruiser Amiral de Gueydon, which has lately been commenced at Lorient, are as follows: Length, 448 feet 6 inches; beam, 63 feet; with a displacement of 9515 tons. She will be driven by three screws, and the engines are to develop 20,000 I. H. P., giving a speed of 21 knots. Her Niclausse boilers will be placed before and abaft the engines, the latter being constructed at the works of Chantiers de la Loire at St. Denis. There will be a waterline belt of hardened steel 6 inches thick, extending from the stem to near the stern, which will be closed by a transverse 3-inch armored bulkhead; above the 6-inch belt will be a second narrower belt of 3.9-inch steel protecting the cofferdam; there will also be two armored decks. The armament will consist of two 19.4-centimetre (7.6-inch) guns, of 93-96 model, in turrets, one forward and one aft, with an arc of fire of 270 degrees; eight 16-centimetre (6.3-inch) Q. F. guns of the same model in armored casemates, so arranged that four can fire ahead and four astern.—Journal of the Royal United Service Institution.
Bouvet.
The new French battle-ship Bouvet is complete, so far as outward appearances go. She is more like the Carnot than her other nominal sisters, but the similarity is only general and at first glance. In the Carnot the big gun in the side turret stands on a sort of redoubt, in the Bouvet it is balanced on an armored pillar. Probably the construction is identical in each case, and the redoubt of the Carnot may have no protective value—it is one of those things that information is not given away about, and on which the foreigner can only speculate. As it stands in the Bouvet, however, the construction looks singularly faulty; in order to obtain an end-on fire from half the entire armament the guns in question have been placed where quite a medium shell would surely put them out of action for good and all. The two smaller guns that help to fill this nest—they are in little turrets fore and aft of and below the larger gun—would share the same fate; in fine, a rational distribution of armament has been sacrificed in order to obtain an end-on fire— on paper. In action these guns, fired right ahead or astern, would probably blow away smaller turrets that project on the beam and quarter, in any case the blast would make matters singularly unpleasant for the guns’ crews. The Bouvet has little in the way of military tops; such as she has are placed low down; higher up there are only search-light platforms. The stern is built up and quite as high as that of our Majestic’s; in the Carnot, Martel and Massena it is low. The bow gun is about 30 feet above the water-line. Still higher, on a light superstructure, the 3.9-inch quick-firers are carried; two on each side are directly over the amidships side barbettes, and certainly look as though they would be incommoded in action by the fire of the big gun just beneath them. The new French armored cruiser d’Entrecastaux is practically complete. She is best described as a small edition of the Charlemagne—a small edition, that is, in the same sense as our Powerful is an adaptation of the Majestic type to a cruiser design. The most noticeable feature of the d’Entrecastaux is the arrangement of the funnels, the aftermost of the three being set back by the mainmast, with a large gap between it and the second. The tops of the funnels also have, for a warship, a somewhat eccentric appearance, being much like those of railway locomotives. Some Scandinavian monitors are the only other warships in existence with funnel tops of this inverted bell shape, but in the case of the monitors they are still more pronounced.—The Engineer.
[Japan.]
Asama.
On Wednesday, March 23rd, there was launched from the Elswick shipyard a first-class armored cruiser for Japan. At the luncheon, after the launching had been successfully accomplished, Sir Andrew Noble made a speech, from which we are tempted to reproduce the following extracts, as they explain very fully the characteristics of the vessel and her armament:
The vessel, he said, that they had seen launched by Madame Arakawa was, he ventured to think, a remarkable one. Her length was 408 feet, her breadth 67 feet, her mean draught 24 feet 4¼ inches, and her displacement 9700 tons. Her machinery was of the twin-screw triple-expansion type, built by Messrs. Humphrys and Tennant, with a maximum indicated horse-power of 18,000, while her armament was very powerful, he might say remarkably so. It consisted of four 8-inch breech-loading quick-firing guns, fourteen 6-inch quick-firing guns, twelve 12-pounder quick-firing guns, seven 2½-pounder quick-firing guns, and five torpedo tubes, four being submerged, the latter being the class with which, as he had had occasion before to remark, they had achieved a remarkable success. But if he came to the Asama’s defensive powers, they were nearly as remarkable. She had at her water-line a belt of Harvey steel 7 inches thick, her citadel was 5 inches thick, whilst her barbettes were 6 inches thick. Her conning tower was 14 inches thick and her casemates were 6 inches thick. Her protective deck was 2 inches thick from end to end. Both in the public press and elsewhere the question of cruisers and armaments had excited much attention of late, and so many comments had been made that he felt impelled to make a few explanatory remarks himself. In the first place, as he had said, the whole of her armor was Harveyed, and they must remember that Harveyed steel was at least equal to one and a half times the defensive power of compound armor. The radius of action of the Asama was about 10,000 knots at her most economical speed, and that was more than ample radius of action for the duties she was likely to be called upon to perform. As regards her armament, perhaps the most convenient way of expressing the Asama’s very great power was by comparing her with the armament of the Powerful, which was one of the fastest cruisers in her Majesty’s service. The main armament of the Powerful consisted of two 9.2-inch breech-loading guns, twelve 6-inch quick-firing guns, fourteen 6-inch quick-firing guns, and eighteen 12-pounders, whilst the armament of the Asama amounted to four 8-inch quick-firing guns, fourteen 6-inch quick-firing guns, and twelve 12-pounder guns. But they would observe that the whole broadside of the Powerful throws only a weight of shot at a single broadside amounting to 1472 pounds, while the broadside of the Asama amounted to no less than 1775 pounds. They would remember also that the Powerful was a vessel of, he thought, 14,500 tons displacement, whilst the Asama was only of 9700 tons displacement, and her maximum speed was 21½ knots. Turning to the guns, those 8-inch guns of the Asama had a maximum muzzle velocity of 2560 feet per second; but, for reasons which he should come to presently, it was not desirable that that high velocity should generally be used. It was a mistake to suppose that such high velocities were new. That firm had turned out and armed many ships with guns of a velocity of over 2500 feet per second. Further, they made experiments to show that with the new explosives that were now in general use elsewhere, it was possible to get, taking the 6-inch guns as an instance, a velocity of about 3000 feet per second. But it would be in the highest degree unwise to use those very high velocities, except for very exceptional occasions, the reason being that the erosion was so extremely rapid that in a very few rounds the velocity falls off enormously, to the extent of 300 feet or 400 feet, and in comparatively few more rounds the gun becomes unserviceable and requires relining, simply because the surface of the bore is swept away by the heat and pressure of the charge. It was also a mistake to suppose that it was a novelty to fire those high velocity quick-firing guns without the use of brass cartridge cases. The Elswick firm had turned out quick-firing guns of all sizes for some years without cartridge cases. But the point was, perhaps, too technical to dwell upon there. Both cartridge cases and guns without cartridge cases had their defects and had their advantages. With very high velocities it was, perhaps, preferable to dispense with the cartridge case, but that was a question that was open to discussion.—The Engineer.
United States Built Cruisers for Japan.
Of the two cruisers being built in the United States for Japan, that under construction at the Union Ironworks of San Francisco, Cal., and soon to be launched, is typical. She is a substantial duplication of the Buenos Aires, built at Elswick in 1895 for the Argentine Republic, with some modifications in armament, and may be said to be a development of the Yoshino. The general features and principal dimensions are: Length on load water-line, 405 feet 2 inches; beam, extreme, 49 feet; normal draught, 17 feet 7.25 inches; normal displacement, 4760 tons; normal coal supply, 350 tons; total bunker capacity, 1000 tons; estimated maximum indicated horse-power, 15,000; estimated maximum speed, 22.5 knots; complement, 405.
The ship has a double bottom extending from bow to stern and reaching well up above the water-line. There are something like fourteen main water-tight compartments, and numerous minor subdivisions. There will be a cofferdam on each side running well forward and aft, but it is 28 not the purpose of the Japanese to fill the space with cellulose at present. A protective deck, reaching from side to side, and running from the stem to the stern, completely covers the vitals. On the flat portions this deck is ¾ inches thick, but on the slopes at the sides it is increased to 4½ inches. All woodwork is to be fireproofed by the present prevailing electrical process. The ship will be driven by twin screws, actuated by two sets of triple-expansion engines of the four-cylinder type, having cylinders of 40 inches, 60 inches, 66 inches and 66 inches diameter respectively, with a common stroke of 36 inches.
Steam will be supplied by eight boilers, four double-ended and four single ended, having a total grate surface of 792 square feet, and a total heating surface of 22,440 square feet; working pressure about 180 pounds. There are two engine-rooms and four fire-rooms, the latter being closed when under forced draught. The bunkers are so arranged that the coal comes in directly on the fire-room floor.
The principal offensive power of the ship is centered in a very formidable battery of quick-firing rifles. In the main battery there are two flinch and ten 4.7-inch rapid-fire rifles; and in the secondary battery there are twelve 12-pounders and six 2½-pounders. One 8-inch gun is mounted on the forecastle deck, the other on the poop deck, and each has a commanding arc of fire of 270 deg. The gun crews are protected by shields on each piece. These 8-inch guns are of the Armstrong type, and, together with the rest of the batteries, will be purchased in England and placed on board the ship when she reaches Japan. The 4.7-inch guns are mounted in sponsons on the main deck, and are sheltered by shields and the 3-inch sponson armor. The forward gun on each side and the after gun on each side have separately an arc of fire of 130 deg., the forward guns being able to fire dead ahead and the after guns being able to fire dead astern. The rest of the 4.7-inch rifles, and such of the 12- pounders as are sandwiched between on the main deck, have arcs of fire of 100 deg. The 12-pounders have the same 3-inch sponson armor about them. The four remaining 12-pounders are mounted forward and aft in sponsors near the bow and stern. The 2½-pounders are placed on the hammock berthing and up in the military tops. The 8-inch and the 4.7- inch rifles will be supplied with ammunition by electrical hoists, while the supplies for the smaller guns will be raised by whips from the magazines. A torpedo outfit of five tubes has been called for, two on each broadside and one in the stem, but there is reason to believe the bow tube will be removed. The value of such tubes has long been known to be more than questionable.
The ship will be lighted by electricity, and ventilated by natural and artificial means; and the fittings, so far as consistent with the Japanese regulations, will conform to the best American practice. The contract price is reported to be something like £205,000.—The Engineer.
[Russia.]
Pereswiet.
The new first-class Russian battle-ship Pereswiet was launched at the Baltic Works on the Neva in the presence of the Czar and Czaritza and a large concourse of distinguished spectators, including the members of the foreign Diplomatic Corps and many foreign officers. The keel of the Pereswiet was laid down in November, 1895. Her chief measurements are: Length, 434½ feet; width of beam, 71½ feet; depth below water-line, 26 feet; and displacement, 12,694 tons. She has three screws, and will be fitted with three vertical engines of triple expansion, each calculated to develop 4800 indicated horse-power, with 30 Belleville boilers in six groups, having a total heating surface of 43,418 square feet. The turrets for 10-inch guns are being made at the Nevsky Works, and the carriages for the smaller artillery at the Oboukhoff Works.—Engineering.
[Spain.]
Pelavo.
The near approach of war has naturally caused the utmost activity in the Spanish Navy, and the most earnest efforts are being made to get every available vessel into commission with the least possible delay. The ironclad Pelayo, at the time the Cuban question reached an acute stage, was in dock at Toulon, where she was being refitted with a new boiler installation, Niclausse boilers being substituted for those already in the ship. In such a crisis no attempt could be made to carry out complete trials; and a full-power trip was the most that could be done, but the conditions under which it was made, and the results given by the new boilers, seem sufficiently remarkable to merit notice.
The pipe work was not completed till the evening of April 6, and up to that time it had only been possible to raise steam in two out of the 16 boilers. Owing to the want of steam pipes the remaining 14 had never even had a fire below them. There was no time to try them, however, and early on the morning of April 7 the Pelayo sailed with all her boilers under steam. In two hours after leaving she attained her full speed of 16 knots with natural draught, all boilers being at work, and she maintained this speed during four hours. The horse-power developed was 8000. The boilers throughout worked satisfactorily, and the pressure was maintained with ease, although the stokers were exclusively Spanish merchant sailors, mobilized in readiness for war, who for the most part had no knowledge of boilers; the complement also was very incomplete.
The results were so satisfactory that the Spanish commissioners decided to accept the machinery at once, and towards four o’clock in the afternoon the Pelayo continued her voyage to Carthagena, after landing the contractors’ representatives.
The Niclausse boiler is in use on several other Spanish war vessels, among which may be mentioned the cruiser Cristobal Colon, of 14,000 horse-power, and on many ships of the French and other navies. The run above described well maintains the reputation of its previous performances, the most striking of which was the recent test of the French cruiser Friant, under what were intended to be actual service conditions. It will doubtless be remembered that she was suddenly ordered to leave Quiberon, run to Cape Finisterre at 17 knots, then cruise in the Atlantic for six days and nights at 16 knots, watching for an imaginary enemy, and finally return to Quiberon at 17 knots. This she successfully accomplished without any special preparation. The present performance is, perhaps, even more remarkable, seeing that only two of the boilers had been under steam before; and it speaks well for the quality of material and accuracy of workmanship employed, that the whole 16 worked without hitch at full load from the moment of first lighting the fires under them; while the ease with which the pressure was maintained, in spite of the utter inexperience of the stokers, is conclusive evidence of the steaming powers of these boilers.
The following is a brief description of the boiler installation on the Pelayo, with leading particulars and dimensions: There are 16 boilers in all, divided into four similar groups, two forward and two aft. The two forward groups are separated from each other by longitudinal watertight bulkheads; and the after groups are divided in the same way. Each group thus consists of four boilers, which are arranged in pairs; the two pairs are placed back to back with no space between, and the fronts run athwartship. This arrangement, which is only possible with boilers permitting all operations, whether of working or overhauling, to be performed from the front, is very economical of space.
It will be seen from the above that each group has two stokeholds, each stokehold serving for two boilers. These stokeholds are very large, because the length of the Niclausse boilers is much less than that of the old cylindrical boilers. Thus the forward and after stokeholds of the two after groups are 20 feet and 8 feet 8 inches wide respectively, and are of the full half-width of the ship; there is a passage from the forward to the aft stokehold in each group 2 feet 2 inches wide between the boilers and the side. The forward and after stokeholds of the two forward groups are 20 feet 9 inches and 8 feet wide respectively. It is evident that a portion of these spaces is available as auxiliary store-rooms, etc., since a width of 7 feet 10 inches is sufficient for the withdrawal of the tubes and other operations. There are two funnels, one for each pair of groups. Each boiler consists of 15 headers, each containing 18 tubes. The tubes are of steel, all lap-welded, except those of the lower rows, which are weldless; their external diameter is 3.2 inches, and their thickness .137 inch; they slope to the rear at an inclination of 1 in 10, and are fixed in the headers by metallic-coned joints, like all boilers of the Niclausse manufacture.
The steam and water drums are 9 feet long and 2 feet 8 inches in diameter, and the headers are attached to them by the ordinary double cone joints. On the top of each drum is a small steam drum inches high in which is the intake of the steam pipe. The other end of this pipe is connected to the steam outlet on the drum which supplies the steam pipes both for the main engines and the auxiliary machinery. Within the drums are placed the mud catchers, the guide pipes for the descent of water into, and ascent of steam from such header, two feed pipes, and the cock to which the steam jet used in cleaning the outside of the tubes is connected to the outside of the drums are the safety valves, the “Soupape avertisseuse,” water-gauge fittings, pressure gauge, two feed valves—one to the pump on the main engine, the other to the auxiliary pumps— a blow-off cock, a “robinet de plein,” and an automatic feed regulator. The bottoms of the headers of each boiler are connected by a pipe with a blow-off cock discharging into the main blow-off. Each boiler has three fire doors, three ashpit doors and two main doors in the front of the headers. For the safety of the stokers, in case of a tube bursting, the fire and ashpit doors open inwards, and consequently close automatically under internal pressure; the fire doors are also balanced.
The following are the principal particulars and dimensions of the installation: Number of boilers, 16; number of furnaces per boiler, 1, total 16; number of heaters per boiler, 15, total 240; number of outer tubes per boiler, 270, total 4320; number of inner tubes per boiler, 270, total 4320; diameter of outer tubes, 3.22 inches; diameter of inner tubes, 1.57 inches; length of outer tubes, 7 feet 1 inch; length of inner tubes, 6 feet 11 inches; grate area per boiler, 53.25 square feet, total 852 square feet; heating surface per boiler, 1760 square feet, total 28,160 square feet; heating surface -f- grate area = 32:1; floor space occupied per boiler, 76.25 square feet, total 1220 square feet; grate area per square foot floor space, .7 square foot; heating surface per square foot floor space, 23 square feet; horse-power, 85; water space per boiler, 120 cubic feet, total 1920 cubic feet; steam space per boiler, 25.4 cubic feet, total 4064 cubic feet; number of fire doors per boiler, 3, total 48; number of ashpit doors per boiler, 3, total 48; number of funnels, 2; pressure, 170 pounds per square inch; weight of boilers, including framework, setting, valves and cocks, tubes and headers and drums, 255 tons; weight per square foot of heating surface, 20 pounds; weight per square foot of grate area, 620 pounds; weight of boilers as above, including water and all accessories, 345 tons; weight per square foot of heating surface, 27.4 pounds; weight per square foot of grate area, 900 pounds.
The foregoing particulars possess a special interest at the present time, when the Pelayo will unfortunately be employed on active service.— Engineering.
Spain’s Armored Cruisers.
The admission of vessels into the category of armored cruisers is governed so much by individual fancy that the term is in many cases very misleading. It might well be divided into at least three subheads, or else abolished altogether, for at present variations are so great that comparisons between ships designated as “armored cruisers” are well nigh impossible. There are cruisers, all called “armored,” without any other distinction: (1) With armor on both guns and belt; (2) with armor on belt only; (3) with armor on the guns only. To the latter class the Spanish cruiser Carlos V belongs, but as a general—and quite unreasonable—rule ships with armor for the guns only, like our Powerful, are classed as first-class protected cruisers, while a thin 3-inch belt will dignify them with the title of armored cruiser. If we compare the majority of Spanish cruisers, the Vizcaya and Infanta Maria Teresa class with their battle-ship Pelayo, we see that the sole difference between them is that where the Pelayo has a belt all around her the Vizcayas have a partial belt for three-quarters of their length and bulkheads. The Pelayo has, of course, four big guns against their two, but then she is the bigger ship.
In both cases the guns are identically protected, a narrow barbette, with nothing below save an armored hoist. In each case a thin shield covers the gun breech—a foolish thing probably, since it is just sufficiently thick to burst a shell and far too thin to keep anything out. Before Yalu the Chinese removed these shields from their battle-ships, and there was probably wisdom in so doing, though we must bear in mind that the Japanese have since replaced them in the Chin Yen. Probably, however, the new shields are of tougher armor, but on that no details are available.
We find, therefore, that to all intents and purposes the Spanish Vizcaya class are battle-ships of the second class, slightly armored, it is true, yet with more armor than the Italian Lepanto carries, since that “ironclad” has no belt at all. A vessel which—save that she has a 2-inch armor over the quick-fire guns—is identical to the Italian Lepanto in the arrangement of armor is the Carlos V. She has no belt, but a very thick deck—6-inch —her big guns in fore and aft barbettes alone are armored. The arrangement of guns is, of course, quite different to the Lepanto’s, but the “idea” in both ships is similar. This idea is that a belt of coal and cellulose, with a thick deck below it, is quite equal to a heavy belt of armor. So far as protecting the engines goes this is true; and it may prove true in other ways. At the best, a belt is only a strip, liable to penetration above and below in a seaway.
The Cristobal Colon could, and no doubt will, “lie in the line” if there is a naval action; she is proof against every sort of shell. Except her and the Pedro d’Aragon, now building, which carry io-inch guns, all the Spanish armored cruisers carry a couple of n-inch guns, very good pieces, able to penetrate all the armor on the American battle-ships’ guns.
The American armored cruisers are quite different; they are really armored cruisers. Their belts, instead of being 12-inch steel as in the Vizcayas, are of 3-inch steel only; their big guns are only of 8-inch calibre. Now, an 8-inch projectile is quite useless against the belts of the Vizcayas, or against their barbettes, and in engaging such ships shell fire alone could be depended on to do anything. Of course shell fire is the staple attack, but the Brooklyn and New York can do nothing against the Spaniards with their comparatively feeble 8-inch shell that the Spaniards cannot do against them with a far more powerful gun. It is rank heresy maybe, but we cannot but hold that there is a tendency to unduly glorify the small quick-fire gun or the medium-sized 8-inch. The chances of hitting are, of course, greater with the smaller weapon, both from its extra rapidity and its extra numerical quantity; but when the big shot does hit its effect will be, of course, far greater. However, the metier of the Spanish and American armored cruisers is quite different, and it is profitless to compare them. Spain’s force is really a number of second-class battle-ships—known as “armored cruisers”—and these will be pitted against a much smaller number of first-class American battle-ships. The “many eggs in one basket” is, when all things are considered, the best for battle-ships. America therefore, apart from other considerations, should win. It is not very safe to prophesy anything, but the probabilities are either a “walk over” for one side or else an absolutely indecisive but sanguinary result. There is not likely to be a mean between these extremes.
The other principal data with regard to the vessels referred to above are as follows: The Vizcaya is an armored cruiser, launched at Bilbao in 1891, carrying two 11-inch guns in two barbettes, and ten 5.5-inch guns, besides smaller weapons. Her displacement is 7000 tons, her length 340 feet, breadth 65 feet, and maximum draught 21 feet 6 inches. She is propelled by twin screws, her engines developing 13,000 horse-power. Her normal coal supply is large, namely, 1200 tons, sufficient to take her nearly 10,000 miles at 10 knots. Her maximum speed is 21 knots. With the exception of the Pelayo, she and the vessels of the same class are the most heavily armored in the Spanish navy. They have belt armor 12 inches thick, extending from bow to stern, but tapering off at the extremities; their big guns are protected by 10½ inches of armor, and the deck plating is 3 inches thick. The Infanta Maria Teresa, also built at the same time and in the same yard, develops rather more power, but is armed and protected in the same way, and is of the same dimensions. Both ships have six torpedo tubes. The Almirante Oquendo, Cataluna, Cardenal Cisneros, and Princessa de Asturias are all very nearly the same in dimensions, and all carry the same guns and armor, so that these six ships form a valuable squadron, and as the slowest of them can steam 20 knots, they ought, if combined, be able to give very good account of themselves.
The Cristobal Colon, originally Giuseppe Garibaldi II, is of rather less displacement—6840 tons—and indicates 14,000 horse-power, but makes only the same speed as the Vizcaya class. Her main armament consists of two 10-inch guns and ten 6-inch, and six 4.7-inch and four torpedo tubes, so that she is powerful in this respect. She is protected by a 6- inch belt of Harveyed steel, and her guns are similarly provided. Her deck plating is 1½ inches thick. Her normal coal supply is 1000 tons. She was launched at Sestri Ponente in 1896.—The Engineer.
[United States.]
Kearsarge and Kentucry.
The U. S. battle-ships Kearsarge and Kentucky were successfully launched from the yards of the Newport News Shipbuilding Company on March 24. The Kearsarge was christened with a bottle of champagne, the Kentucky with water from a cut-glass bottle, but several enthusiastic Kentuckians hurled some bottles of good old whiskey against the sides of the Kentucky at the same time. The following are some of the principal facts concerning the ships: Each of the vessels is 385 feet long, 72 feet 2.5 inches beam, 14 feet 3 inches freeboard forward, and 12 feet 3 inches freeboard aft. Their draught, with 410 tons of coal on board, is 23½ feet; their displacement is 11,525 tons. In their turrets they will each have four 13-inch and four 8-inch guns. There will be four torpedo tubes, two on either broadside. The armor will be of solid nickel steel, Harveyized. The lower part of protection will have armor 15 inches in thickness. The armor of the turrets will also be 15 inches, except immediately in front, where it will be made 17 inches. In addition to these heavy guns a battery of fourteen 5-inch rapid-fire guns, a numerous battery of smaller 6-pounder and 1-pounder guns will be carried, such guns being placed wherever they can fire to advantage. The protection of the hull to the water-line region will be effected by means of a side armor belt of a maximum thickness of 16½ inches, with a mean depth of 7J4 feet, so disposed in reference to the load line that the vessel with 410 tons of coal on board will have 3½ feet of this belt armor above the water, and with 1210 tons of coal on board will have 2 feet above the load line. The belt will extend from the stem to the after barbette, and will maintain the maximum thickness from the after end of the belt to the forward boiler-room bulkhead, whence it will taper gradually to a thickness of 4 inches at the bow. The conning tower will have armor 10 inches thick, with a tube 7 inches in thickness leading down to the armor deck for the protection of the voice pipes, telegraph, steering rods, etc. The vessels will be driven by triple-expansion engines actuating twin screws, the engines having a collective horse-power of 10,000 when making about 120 revolutions a minute. Five boilers, three double-ended and two single-ended, in four water-tight compartments, will generate the necessary steam at a pressure of 180 pounds to the square inch. The vessels will carry a supply of coal of 1210 tons.—Engineering.
Alabama.
The United States battle-ship Alabama, the first to take the water of the three new vessels of her type, was successfully launched at noon on Wednesday, May 18, from the yard of the William Cramp & Sons Shipbuilding Company, Philadelphia. The naming ceremony was performed by Miss Morgan, daughter of the senior Senator from Alabama. The building of the Alabama, as of that of her sister vessels, the Illinois and the Wisconsin, has been delayed over a year by the failure of the last Congress to make provision for the supply of their armor plate. Otherwise the battle-ship would now have been fitting out for service instead of being launched.
The general dimensions of the Alabama are as follows: Length over all, 374 feet; breadth, 72 feet; freeboard forward, 20 feet; freeboard abaft the after turret, 13 feet 3 inches; draft, 23 feet 6 inches; displacement, 11,525 tons. The guaranteed speed is to be 16 knots and the estimated horsepower 10,000. The main battery consists of four 13-inch guns in two turrets and fourteen 6-inch rapid-fire guns, of which ten are mounted on the gun deck—eight in broadsides between the turrets and two forward of the fore turret, to fire straight ahead—and four are mounted in a small redoubt on the casemate deck, two on each side. The secondary battery embraces seventeen 6-pounder rapid-fire guns, six 1-pounder rapid-fire guns and four gatlings.
The armor, armament and speed of the Alabama, with a displacement of 11,525 tons, compare favorably with that of the latest type of battleships built abroad with a displacement of 15,000 tons. The maximum thickness of armor on the water-line is 16½ inches, tapering to 9½ inches at the bottom of the belt. The casemate armor is 554 inches thick and the superstructure armor is of the same thickness. The armor of the 13-inch gun turrets is 15 inches thick, except the port hole plate, which is 17 inches. The armor of the barbettes on which the turrets rest is 15 inches thick. The thickness of the protective deck armor on the flat over the citadel amidships and also forward and aft is 2¾ inches, and the thickness of the slopes forward and aft of the amidship citadel is 4 inches. The conning tower is cylindrical and 18 inches thick. The total weight of armor and bolts is 2720 tons and the protective deck armor 593 tons. The weight of armament with normal supply of ammunition, which is two-thirds of the full war supply, is 864 tons. The two engines of the Alabama will be of the vertical three-cylinder type, operating twin screws. She will be equipped with eight single ended boilers, placed athwartships.—Iron Age.
U. S. S. New Orleans (Amazonas)
The United States Government have been buying or trying to purchase ships of war in various directions, and with varied success. The Brazilian Government have sold two, probably at a considerable profit, namely, the Amazonas and her sister the Almirante Barroso. The former has been lying off Gravesend all the week.
The Amazonas was built at Elswick, and is a very fine vessel. She has a displacement of 3600 tons, is 330 feet long, 43 feet 9 inches beam; her mean draught is 16 feet 10 inches, her horse-power 7000; she carries for her size a tremendous armament, including six 6-inch quick-firers, four 4.7-inch quick-firers, ten 6-pounders, four Maxims.
A 3-inch protective deck extends from stem to stern, and additional protection to the machinery and boilers is afforded by the reserve longitudinal bunkers, which carry coal to a height of about 6 feet above the water-line. The Amazonas attained a speed of 20 knots with natural draught, and 21.05 knots with forced draught. The gun positions are protected by 4½-inch armor. A very powerful fore-and-aft fire can be obtained, as two of the 6-inch guns are in shields on the poop and forecastle, and the other four are sponsoned out, two forward and two aft. The 4.7-inch guns are carried in recessed ports, so as to be clear of the fire of the larger pieces. The ammunition is supplied through hoists worked by electric motors.—The Engineer.
Features of the New Battleships.
Secretary Long has just published a circular which defines the characteristics of the three seagoing coastline battle-ships authorized by the new naval appropriation law. It is proposed that the new ships shall have a load water-line of 368 feet; the breadth at water-line will be 72 feet; and the mean draught at the normal displacement 23½ feet; the normal displacement is to be 11,500 tons and the total coal capacity 1200 tons. The hull is to be of steel, with a double bottom, and is to be subdivided by watertight compartments. The hull at the water-line is to be protected by an armor belt of a maximum thickness of not less than 16½ inches and a mean depth of 7 feet 6 inches. This belt is to extend at least from the stem to the after barbette and to maintain the maximum thickness through the engine and boiler spaces. From the boiler space forward it may be tapered to a uniform thickness of 4 inches. The transverse armor just forward of the boiler space and at the after end of the belt will not be less than 12 inches in thickness. Throughout the length of the vessel a protective deck is to extend. Where this deck is worked flat the total thickness will not be less than 2¾ inches, and where worked with inclined sides the slope will be 3 inches in thickness forward and 5 inches in thickness aft. A cellulose belt is to be fitted along the sides for the whole length of the ship. The barbettes for the 13-inch guns will have armor 15 inches thick, except in the rear, where it will be reduced to 10 inches. The turret armor is to be 14 inches throughout. The ship’s sides, from the armor belt to the main deck, will be protected by not less than 5½ inches of steel armor from barbette to barbette. Coal is to be carried back of a portion of this 5½-inch casing armor.
In a suitable position will be a conning tower of not less than 10 inches in thickness, having an armored communication tube 7 inches in thickness. Four 13-inch guns will be mounted in two heavy barbette turrets on the midship line, one forward and one aft. There will be ten 6-inch rapid-fire guns in broadside on the main deck, four on the upper deck within the superstructure, and a secondary battery of twenty-four rapid- fire and machine guns. The 6-inch guns on the upper deck will be protected by 5½-inch armor. There will be two submerged torpedo tubes. The torpedo compartment will be fitted up for the storage of eight 17- foot torpedoes and appliances and means for operating and handling the same.
The vessels will be driven by twin screws. The engines will be of the vertical triple-expansion four-cylinder type, two in number, one on each shaft, and they will be placed in separate watertight compartments. The eight boilers are to be cylindrical and single ended. They are to be placed in four separate watertight compartments, and will work at a pressure of 210 pounds. If on trial the average speed shall equal or exceed the speed at sea of 16 knots an hour for four consecutive hours, the vessel will be accepted as far as the speed is concerned. If the speed falls below 16 knots and exceeds 15 knots an hour, the vessel will be accepted at a reduced price, the reduction being at the rate of $25,000 per quarter-knot, if the deficiency of the speed lies between 16 knots and 15½ knots, and at the rate of $50,000 per quarter knot between 15½ knots and 15 knots. If the speed falls below 15 knots an hour the vessel will be rejected or accepted at a reduced price. No sail will be carried, but two military masts are to be fitted with fighting tops.—Scientific American.
The Destroyers and Torpedo Boats.
The Naval Construction Board has prepared the specifications of the proposed destroyers and torpedo-boats to be built in accordance with the authority conferred by the naval appropriation act. Twenty-eight boats— 16 torpedo-boat destroyers and 12 torpedo-boats—will be built and bids will be invited on the basis that the destroyers shall be of not less than 400 tons nor more than 435 tons displacement, capable of making a speed of not less than 30 knots an hour, and that the torpedo-boats shall not be less than 150 nor more than 170 tons displacement, capable of making a speed of not less than 26 knots an hour. One of the most important requisites of the proposed vessels is that the destroyers shall be able to make a high speed in a heavy seaway and torpedo-boats a high speed in a moderate seaway. The disablement of the boats is guarded against by a provision that the engines and boilers shall be in separate compartments. The destroyers are to have a minimum coal capacity of 100 tons, which will give them a steaming radius of 5000 miles. The torpedo-boats will have a coal capacity of 40 tons, and their steaming radius will be about that now possessed by the torpedo-boat Porter, which is with the division of the North Atlantic Squadron near Porto Rico.
The torpedo-boats are to be supplied with an unusually formidable armament. They are to be equipped with 3-pounder semi-automatic rapid-firing guns and three torpedo tubes, while the destroyers will be given batteries including two 12-pounder and five 6-pounder semi-automatic rapid-fire guns and two torpedo tubes. The total cost of each destroyer is fixed at $295,000 and of each torpedo-boat at $170,000. A balance of $140,000 will remain from the appropriation to meet minor expenses incident to the preparation of plans and other details for the proposed vessels. The contracts will provide penalties for each quarter- knot below the contract requirement and for every day’s delay beyond the time limit to be fixed. It is proposed that the destroyers shall be furnished to the Government within 18 months and the torpedo-boats within 12 months.—Iron Age.
New Monitors.
Plans are being rapidly pushed by the board for the monitors whose construction is authorized by the naval appropriation act. The designing of these vessels is proceeding under the direction of Chief Naval Constructor Hichborn. On account of the small appropriation made by Congress for each of these vessels—$1,250,000—it has been determined to limit their size to 2500 tons displacement, and to supply each ship with a single turret to be placed in the forward part of the vessel. It has not been definitely decided whether to equip them with two 12-inch or two 10-inch breech-loading rifles. The superstructure of the vessels will extend from the turret nearly to the stern, and rapid-fire guns will be placed on this to be directed against torpedo-boats that may attempt to attack the ships. The turret will be so arranged that the guns can be trained over an arc of at least 300 degrees, so that they can be fired in almost any direction except dead astern. These vessels will not be as efficient as the double-turreted monitors, but they will be very effective harbor defenders, and the Department proposes to make them as powerful as possible with the money granted by Congress. They will probably require two years to build.—Iron Age.
Holland Submarine Torpedo Boat.
It is reported that this boat recently made a run of one and a half miles under water, remaining under the surface for twelve minutes. This is the longest run under water which the boat has yet made, and it is stated that she behaved herself very satisfactorily in every respect. A few of the leading particulars of this vessel will be of interest. She is 55 feet long, 10 feet 3 inches in diameter, and of 75 tons displacement. The steel hull is cigar-shaped, and the boat is propelled by a single propeller. The motive power equipment consists of a 50 horse-power gasoline engine and dynamo, the latter being directly coupled through a clutch at each end of its shaft to the propeller shaft and to the gas engine respectively. A storage battery of 60 special type chloride accumulators is installed, the total weight of the battery being 45,000 pounds. The cells are constructed of steel, lined both inside and out with lead, and are stated to be capable of discharging at 300 amperes for six hours or at 1000 amperes for half an hour. The arrangement of gearing permits of the propeller being run by the engine or of the cells being charged, except, of course, when the boat is submerged, when the motive power is supplied from the cells to the dynamo as a motor. Enough fuel is carried in the cellular bottom to propel the boat on the surface for 1000 miles at eight knots. The dynamo is a 50 nominal horse-power machine, weighing 3500 pounds; the armature speed is 800 revolutions per minute; there are two commutators and a double-wound armature; an overload to 150 horse-power is possible without detriment. The normal speed of the Holland is nine knots, at an expenditure of 50 horse-power. A 10 horsepower motor with a 7 horse-power Ingersoll air compressor is installed for supplying air at 2500 pounds pressure to the reservoirs. The compressed air is used to propel the torpedoes, emptying the water ballast tanks, steering and for supplying respiration. A ½ horse-power motor is used to force the foul air into the water when the craft is submerged, and another of the same capacity to ventilate the battery when charging. The boat is caused to sink by an alteration of the pitch of horizontal diving rudders. When above the surface the craft is steered by observation through the port holes of the conning tower; when below the surface, or nearly so, by compass or by a camera-lucida arrangement fitted in a tube. The Holland’s armament consists of an 18-inch torpedo tube opening at the bow of the boat, and three Whitehead automobile torpedoes are carried aboard. There is also an 8-inch aerial torpedo gun at the bow, and pointing aft a submarine gun, both of the latter capable of discharging 8o-pound dynamite shells at high velocities. All the guns operate by compressed air, and can be discharged when the boat is submerged. The crew consists of five men.—The Engineer.
[1] See Engineering, vol. lxii, page 152.
[2] See Engineering, vol. lxi, pages 776 and 831, vol. lxii, page 538, and vol. lxiii, pages 278 and 309.
[3] See Engineering, vol. lxii, page 708.
[4] See Engineering, vol. lxiii, page 12.
[5] See Engineering, vol. lvii, pages 358 and 415.
[6] The coal supply can be greatly increased, on emergency, to 2000 tons in Cressy and Ariadne, and 2500 tons in Powerful classes.
[7] The designed results are given for comparison. These were exceeded just as the results in the Cressy class may be.