TO FIND THE GREAT CIRCLE COURSE BY INSPECTION.
By Lieutenant J. B. Bush, U. S. Navy.
If in the “astronomical triangle” PZM, for M, the celestial body, is substituted N, the place to which a vessel is bound, then the angle at Z, the “azimuth angle,” becomes the “great circle course” from Z to N.
This angle can be taken by inspection from the “azimuth tables” by substituting (i) the difference of longitude for the “hour angle”; (2) the latitude of N for the “declination,” when the “true bearing” will be the “great circle course” from Z towards N, measured from the elevated pole.
The azimuth tables issued by the Navy Department are computed for the sun only, and consequently their use for this purpose is limited to those cases where the place to which the vessel is bound is within the tropics.
An extension of these tables to greater declinations would not only increase the number of stars available for azimuths, but by making this simple method available in all practical latitudes would tend to bring great circle sailing into common use.
COALING WAR-SHIPS AT SEA.
In dwelling upon the advantages conferred upon the war-ship by the introduction of steam, it must not be forgotten that the new power imposed one very serious burden which is making itself increasingly felt as the speed and size of modern ships continue to increase. For whereas the masts and sails of the frigate were good for a cruise of indefinite length, the boilers and engines of the modern cruiser or battle-ship are available for propulsion only so long as there is coal in the bunkers. The radius of action of the steam-driven ship is determined by her capacity for carrying fuel and her distance from an available coaling station.
There are perhaps no operations of a naval war in which this limitation of the steam battle-ship has caused greater inconvenience than in the work of blockading an enemy’s port. In the days of the sailing frigate a ship could lie for months, if need be, in the blockading line, and the full strength of the fleet was maintained unbroken for months at a stretch; but in a modern blockade it would only be possible to count upon a certain percentage of the ships as available, the others being absent in turn, taking on coal at the nearest station. It has been estimated that during the blockade of Charleston in the Civil War fully one-quarter of the ships were absent at any given time for coaling purposes.
The same difficulty presented itself at the blockade of Charleston harbor during the recent naval manoeuvres. Ships whose draft was not over 15 feet entered the harbor, where the water was quiet, and were coaled from barges lying alongside in the usual way; but had the larger vessels, such as the Indiana, Maine, New York and Columbia, drawing from 20 to 26 feet, required recoaling, they would have been obliged to steam away to Port Royal or Newport for the purpose. As it was, all of the vessels that took on coal were obliged to leave their position in the blockade, and its efficiency was impaired in proportion to the number of vessels absent at any one time.
With a view to overcoming the difficulty, the U. S. S. Massachusetts was recently fitted out at the New York navy yard with a coal transporter, which will enable her to take coal either when at anchorage off a blockaded port or when steaming at slow speed in moderately calm water.
[Fig. 1.—Carriage locked to the beam, the load being raised or lowered.]
[Fig 2.—Load locked in the carriage which is free to travel along the beam in either direction.]
The Temperly Transporter is the name by which this new form of hoisting and conveying device is known. The device consists of a traveler running on a suspended beam, which reaches out over the coal barge, towed abeam at a distance of 20 or 30 feet, and is carried from one of the boat cranes of the battle-ship. This beam, which is 60 feet in length, and weighs about 3000 pounds, is suspended from a strap, attached to the crane by four steel guys, and it is prevented from swinging fore and aft by means of other guys which lead inboard and are made fast to the deck of the vessel. A novel form of self-locking carriage is employed, which travels upon the lower flanges of the beam, and is capable of traversing its entire length. The beam is pitched at an angle sufficient to cause the carriage to run out by gravity, and a single hoisting rope coiled about the barrel of the steam winch serves at once to operate the carriage and hoist the load. The rope after leaving the drum is led to a sheave which is secured at the point of suspension of the beam, from thence to a pulley at the higher end of the beam inboard, and from there it passes around a sheave in the carriage and terminates in a hook to which the bags of coal are attached.
In operation we will suppose that the carriage is at the lower end of the beam over the barge, where it is locked automatically to one of the stops on the under side of the beam, the locking gear of the carriage being then in the position shown in the first figure. After the hook is secured to the coal bag, the hoisting rope is drawn in by the winch, the load rises rapidly to the carriage, where a catch on the hoisting chain, striking a lever, automatically locks the load to the carriage and releases the car from the stop above-mentioned on the under side of the beam. This position is shown clearly in the second figure. The further inhauling of the hoisting rope causes the carriage to travel rapidly up the beam. The stops on the under side of the beam are spaced five feet apart, and the carriage is drawn up until it passes that one which is located over the point where it is desired that the bag shall be delivered. The winch is now stopped and reversed, and the carriage moves back until it is arrested by the engagement of the latch, which is shown at the top of the carriage with this particular stop. The dropping of the latch into the stop automatically releases the load from the carriage and it is forthwith lowered to the deck. The bag is then unhooked, an empty bag is put on in its place, and the operation is reversed, the empty bag being run down the full length of the beam and delivered to the barge. The whole operation is performed in less than a minute, and it requires no skill upon the part of the operator. The long reach of the beam permits coal to be taken from a vessel of any description, which may stand off from the battleship a distance of from twenty to twenty-five feet, and the operation may be carried out in any sea in which it would be safe for two boats to lie at anchor at that distance apart. As the transporter is supported entirely from the battle-ship, no part of it can be injured by the rolling from the two vessels.
It will be evident that the coaling ship may be towed at a moderate speed parallel with the war-ship, and that the operation may be carried out with equal success under such conditions. The French navy, which uses this system of coaling extensively, made a successful trial of coaling the Richelieu while she was steaming under the headway of six and a half knots an hour, and they were able on this occasion to transfer one hundred tons of coal in three hours.
After experiments extending over a period of two years, the British Admiralty has now decided generally to adopt the Temperly Transporter for use in battle-ships and first-class cruisers. It is probable that the apparatus would have been adopted before had it not been for its awkward length and the difficulty of stowing it clear of the working parts of the ship. The trials, however, have resulted in most favorable reports, and the commanding officers of the vessels in which the transporter has been tried are unanimously of opinion that the time and labor saved when coaling ship far outweigh the inconvenience occasioned by stowing the gear away. Apart from this, it has been found that the transporter will enable a torpedo-boat or destroyer to fill up with coal from her parent ship when both vessels are steaming at a fair rate of speed, providing, of course, the sea is moderately calm. During a series of tests, forty tons of coal an hour were handled in bags by this device.
LIQUID FUEL.
[Paper by R. Wallis, read at a meeting of the N. E. Coast Institution of Engineers and Shipbuilders at South Shields on February 10, 1897.]
The writer’s experience with this form of fuel has principally been petroleum residues on board of steamships, and the contents of this paper may, therefore, be taken as applying more particularly to its use in this direction.
The application of liquid fuel for the purpose of raising steam in boilers is now no longer in the experimental stage, a large number of boilers, both on board ship and ashore, being fired with this fuel, and there is no doubt that, as the numerous oil fields in the various parts of the world develop, its application will rapidly extend.
In addition to the oil wells of Southern Russia and Pennsylvania, oil has been found in varying quantities in most countries all over the globe. The late Mr. B. G. Nichol, in his paper on this subject before this Institution in 1886, mentions the countries in which petroleum had been discovered. Since that time several of these oil fields have been developed and are now producing petroleum in considerable quantities, especially those of Peru, Burmah, Sumatra, and Beluchistan.
The principal source of fuel oil is Russian petroleum residuum or “astatki”; this is the oil remaining in the distillery apparatus after the lighter naphthas and paraffines have been distilled over. Russian crude petroleum yields a very much smaller percentage of burning oils than American crude oil, as is shown in Table I, but fuel oil in Russia, where “astatki” is used for this purpose, is cheaper than in America, where crude oil is used.
The percentage of the various oils that, with the perfected process of distillation now used, could be obtained from Caucasian naphtha is as follows:
[TABLE I.]
American oils contain a very much higher percentage of burning oils, about 80 or 90 per cent., instead of only about so per cent., as above.
The first steamer to use liquid fuel was the S. S. Constantine, on the Caspian Sea in 1870, and in America it was used on the steamer Thoroughfare in 1885. The first steamer to cross the Atlantic burning oil as fuel was the S. S. Baku Standard in January, 1894.
In addition to the petroleum oils, the following oils have also been used as fuels: shale oil, blast furnace oil, creosote, green, and other tar oils.
On the table are examples of Russian astatki, American crude petroleum, crude petroleum which has been exposed in a lake to the influence of the atmosphere for twelve months, creosote oil, heavy and light tar oils.
Comparing the value of coal and oil as fuel, it will be found to vary considerably according to the quality of the fuel and the circumstances under which each is burnt, oil doing from 1 y2 to times the work of an equal weight of coal; taking the average conditions, the results of extended experience with astatki and crude petroleum show that these oils will be found to do twice the work of coal.
Table II.
[TABLE II.]
Table II shows the analysis of various oils and coals, together with their calculated calorific and evaporative values. This shows a value for oil of only 1½ times that of coal, and therefore some cause other than that of comparative heat value must be looked for to account for the result of a value of two to one in favor of oil fuel which is found in practice. This difference may be accounted for to a great extent by the following causes:
- The combustion of the liquid fuel is complete, whereas that of coal is not; consequently in the former case there is no lost heat in smoke or soot.
- There are no ashes or clinkers, and consequently no fires to clean, with accompanying loss of heat and drop in the steam pressure; the steam pressure and revolutions of the engines being maintained at one point throughout the voyage.
- The boiler tubes are always free from soot and clean, and therefore always in the best condition for transmitting the heat from gases passing through them to the water of the boiler.
- The temperature of the escaping gases may be considerably lower than is required to create the necessary draft for coal firing. With coal, the air has to be drawn through the bars and the fire in the furnaces; by natural draft this requires a temperature of the escaping gases about 600 degrees to 700 degrees Fahr. But in the case of liquid fuel there are no bars or thick fire for the air to force its way through, and the required amount of air can be drawn through the furnaces by a much lower uptake temperature, about 400 degrees to 450 degrees Fahr. being in most cases sufficient.
- The admission of air to the furnaces being under complete control, and the fuel being burnt in fine particles in close contact with the oxygen of the air, only a very small excess of air above that actually necessary for the complete combustion of the fuel is required. With coal, in order to ensure as complete combustion as possible, a very much larger excess of air is required.
In addition to its higher calorific value, liquel'fuel has many other advantages, especially on board ship.
Stowage.—A ton of coal will occupy about 45 cubic feet oi bunker space, and a ton of oil will require about 40 to 43 cubic feet. Assuming that both coal and oil will require the same bunker space per ton, then since one ton of oil fuel is equal to two tons of coal, the bunker space necessary to steam the same distance at the same speed is only one-half. In addition to this, there is no lost space caused by the projection of frames, stringers or beams. Also portions of the ship which, if used as coal bunkers, would be inaccessible, can be utilized for the stowage of oil.
Trimming.—This is altogether dispensed with, the oil being run or pumped into the fuel tanks through a deck connection, and beyond the opening and closing of the distributing valves, no other attention or labor is necessary for the shipment of the fuel; this makes a considerable reduction in the labor, cost, and time occupied. When at sea the oil either gravitates to the furnaces, if the tanks are above them, or is pumped up if below, and no trimmers are required.
Stoking.—The sprayers require very little attention after they are once adjusted, and one man can attend to a large number of furnaces; and there being no ashes or dirt to remove, the stokehold staff can be reduced to a single man for each watch in any ordinary vessel, or in a small vessel the sprayers can be attended to by the engineer on watch in the engine- room, as is done in many of the vessels on the Caspian Sea.
There are also no firing tools to repair or fire bars and floor plates to renew, and the absence of smoke and dust enables the ship to be kept cleaner.
Regarding the various methods which have been adopted for the burning of liquid fuel, these may be divided into three systems: 1, Furnaces into which the oil is run or dropped and burnt without gasifying or spraying; 2, furnaces in which the oil is first wholly or partially gasified; 3, furnaces into which the oil is sprayed.
- This is the oldest form of burning oil, and is illustrated by the following examples:
The step or cup form of furnace, and is the latest form of a very old method of burning oil.
The pan furnace of Biddle, used in North America in 1862.
Richardson furnace, patented in 1864. The bottom of this furnace is covered with ordinary slacked lime, which is kept saturated with the oil to be burned.
Audouin furnace, first tried in 1865, consists of a large number of small tubes from which the oil is constantly dripping, and is carried into the furnace and burnt by the draft through the openings in the front.
The furnaces of St. Claire-Deville, 1868; Wagenknecht, 1870; Kamenske, 1869: MacKine, 1865; Verstract, 1868, and Paterson, 1878, are all similar to one or the other of the above furnaces. The defect of all these is that the air is not brought in close contact with the burning fuel, with the result of imperfect combustion, accompanied by dense black smoke.
- Shaw and Linton’s gas furnace, patented in America in 1862.
Dorsett and Blythe gas furnace, tried in England in i863 on board the
steamer Retriever. It may be observed that the disadvantage of all gas furnaces is that when using heavy residual oils the tarry deposits rapidly stop up the passages and pipes.
- The furnaces into which the fuel is sprayed can be divided into three distinct classes:
- Flat slit sprayers.
- Sprayers in which a jet of steam or air meets a jet of oil at an angle.
- Circular sprayers.
Several attempts have been made to spray the oil by other means than that of the steam jet in order to overcome the difficulty of making up the fresh water drawn from the boilers in the form of steam.
Air under pressure, especially if heated, has been found to give good results, but the flame is shorter, giving a more intense heat for a short distance than the flame from a steam sprayer. More air than steam is required for the spraying of the oil, and the air jets are more noisy than the steam. The danger of an explosion of oil gas in the furnace and combustion chamber when lighting up, especially if the furnace has been stopped for a short time only, is very much greater with air than with steam sprayers.
Comparing the economy of air and steam sprayers (notwithstanding the drawback of having to make up the water lost in steam used by the sprayers), the steam sprayers appear to be the most economical, and are certainly the type mostly in use. The arrangement of the whole of the steam sprayer installation is exceedingly simple and not liable to derangement or breakdown, whereas the compressed air system is complicated and the risk of breakdown increased by the addition of the air compressor.
The essential requirements in a sprayer are: 1, The oil and steam openings must be so arranged that the oil can be sprayed in the finest particles possible; 2, the steam consumption of the burner must be as low as possible; 3, the sprayer must be constructed in such a manner that it can be easily and quickly taken apart for cleaning and quickly replaced; 4, the noise should be reduced to a minimum.
During the writer’s experience and tests with a large number of sprayers, he has found that the “Rusden-Eeles” sprayer conforms more nearly to these requirements than any other. The spray is very fine; in fact, with astatki the flame can be regulated so as to have the appearance and character of a gas flame. The steam consumption is low, and the construction allows it to be quickly and easily cleaned.
In the later sprayers the blow-through cock is omitted, it being found easier and more effective to take the tube out and clean it than to blow the oil space through with the steam.
In arranging an installation, the principal points are; I, The superheating of the steam: 2, ample area in the fuel pipes, especially if heavy oil is used, and in the case of very heavy oils they may be required to be heated; 3, the supply tank should be placed in such a position as to ensure a constant and steady supply to the burner.
Brickwork in the furnaces should be arranged in a manner as to ensure the complete combustion of the fuel in the furnace and to prevent the too rapid cooling of the furnace after the flame is extinguished.
In some cases, where the boiler is placed in confined space or there is not height enough to obtain a steady pressure on the burners from the supply tank, the oil may be pumped direct to the burners if a controlling valve is connected to the steam pipe of the pump. This valve will regulate the speed of the pump automatically and maintain a constant pressure in the oil supply pipes, no matter how many sprayers may be in use.
In relighting a furnace which has been extinguished for a short time lies the greatest danger of explosion of oil gas and the accompanying back flash from the furnace doors. Any small leakage or drip of oil finding its way into the heated furnace gasifies and forms an explosive mixture with the air, and if the lighting-up torch is introduced into a furnace under these conditions an explosion is sure to take place, and the person introducing the torch is very possibly burnt. Before lighting a furnace it should be well blown through with steam and care taken to see that the steam jet is open first and the torch placed in the furnace before the oil valve is opened, in order that the spray may ignite as soon as it enters the furnace. If these precautions are. taken there is not the slightest danger of explosion, even if fuel with low flash-point is used.
The result obtained by several experimenters, that the average evaporation of liquid fuel is twice that of coal, has been confirmed by a long series of experiments conducted by the writer under the instruction of the Wallsend Slipway and Engineering Company, Limited, with various sprayers.
The boiler, which is of the ordinary marine type, evaporated with coal fuel from 7 to 8 lbs. of water from and at 212 degrees Fah. for each pound of coal burnt, the uptake temperature being about 450 degrees Fahr. with Russian astatki. The evaporation was from 13 to 16 lbs. from and at 212 degrees Fahr. per pound of oil. The following are the average data from some experimens with a Rusden and Eeles sprayer, and a heat account from the same data:
Kind of liquid fuel, Russian astatki:
Specific gravity ................................................. 0.9
Chemical analysis (approximate) ....................... 87 per cent
Carbon ............................................................. 12 "
Oxygen ............................................................ 1 "
Temperature of stokehold.................................. 60° Fahr.
Temperature of escaping gases ........................ 450° "
Weight of steam required to spray 1 lb. of oil. 0.3 lb.
Assuming that the air contained 23 per cent, of oxygen, and that the excess of air over that required for complete combustion passing into the furnace was 20 per cent., which would be about correct, for the slightest reduction of air caused smoke to issue from the chimney:
[TABLE]
Mechanical Engineers, shows how he has successfully applied it to scrap welding furnaces.—The Steamship, April, 1897.
THE DUM-DUM BULLET.
Surgeon-Captain G. S. Mansfield, Medical Staff, has drawn up an instructive report on the experiments with the special Dum-Dum bullet carried out before the commander-in-chief in India, at Meerut, in December. These experiments, which were intended to demonstrate the amount of “set-up” and “stopping power” in the bullet, were made, says the Times of India, on the carcases of freshlv-killed sheep tied up in various positions, some with the fleece on and others with the outer skin removed. Except in one instance, the range was 200 yards, and the sheep were fired at broadside on, diagonally, and facing the shooter, in the last-named position the long axis of the body being exactly in line with the line of fire. The most remarkable result of the experiments was the large size of the “wound of exit.” One bullet fired at an unskinned sheep broadside on passed between two ribs, making an entrance wound no larger than a big pea, but after shattering one of the spinal vertebra, it smashed two ribs and produced an exit wound as large as a crown- piece. Another bullet fired under similar circumstances entered the abdomen behind the last rib, making a wound of entrance as large as a three-penny bit. On its exit a hole was torn in the opposite wall of the abdomen the size of a large orange. Yet another bullet fired at the same sheep pierced the lower jaw at its angle, making a hole in the skin no bigger than a pea, but on examination it was found that the bone was completely shattered. The report gives details of several other shots. One in particular may be noted, that in which the bullet, passing through the thigh, struck the pelvic bone, which apparently offered such resistance that an exit wound 2½ inches in diameter was the result. Surgeon-Captain Mansfield mentions as particularly important, the case of a bullet which entered through the front of the shoulder-joint by a very small opening, and, passing through the joint, completely disorganized it. The articular ends of the two bones were smashed into over a dozen pieces and there was great loss of substance. This wound may fitly be compared to a shot through a man’s wrist or knee, and under similar conditions the bullet would be certain to immediately disable him, excision of the joint, or more possibly amputation of the limb, being the only remedy available. It does not require an expert’s knowledge, says our contemporary, to perceive that such wounds, if inflicted on a human being, must necessarily put an effectual “stop” to his advance, even if they do not always prove fatal. The efficacy of the Dum-Dum bullet is specially vindicated by the character of the wounds which only affected the soft parts. From these wounds Surgeon-Captain Mansfield infers that a bullet penetrating the muscular tissue only, such as that of the human thigh, will “set up” sufficiently to cause a severe wound, quite enough to effectually stop the progress of the man or the horse struck. It has been noted that all the shots except one were fired at a range of 200 yards. The exception was that of a shot fired at 50 yards from the animal. It struck the sheep’s abdomen, soft parts alone being injured; yet though the wound of entrance was small, the bullet on emerging tore a hole the size of an orange. This shot exemplifies beyond all reasonable doubt the superiority of the new bullet over the old one. Bullets manufactured by the new method do not produce clean-cut wounds at close range, as was the case with the old bullets, but are now shown to possess an exceptional “stopping power.”—United Service Gazette, May 8, 1897.
TESTS OF ARMOR AND SHELL.
[United States.]
Built-up Armor.
Washington, D. C., May 11, 1897.—The Navy Department has made an interesting test to determine the efficiency of two thin armor plates superimposed on each other in close contact, as against the resisting power of a single plate of their combined thickness, the result demonstrating to the satisfaction of the Department that the single thick plate is a considerably more effective barrier against armor-piercing shells with service charges than the thin plates. The experiment was made for the purpose of determining whether in case the emergency should arise it would be practicable to provide certain armor for the three new battleships by having thin plates made to be used in lieu of the thick plates, which cannot be produced within the limit of cost, $300 per ton, fixed by Congress in the Navy Appropriation bill. The thin plates, it was decided, could be manufactured by any one of a considerable number of steel makers and could be produced in large quantities at short notice at $300 per ton, or less.
The tests were made at the Indian Head Proving Grounds of two nickel steel, reforged, face-hardened plates, superimposed one on the other. The gun used was a 10-inch breech-loading rifle, No. 26, on a station hydraulic mount. The charge was 237 pounds of C. G. 2 powder. The striking velocity, measured by the chronograph, was 1952 foot seconds and the striking energy was 13,223 foot tons. The projectile was a Carpenter 10-inch armor-piercing shell, No. 267 of lot 1, hardened to 0.5 inch below bourrelet, the weight of projectile being 500 pounds. The distance between gun and plate was 394 feet.
The plates were 6-inch face-hardened nickel steel plate B 525 and 5.5 inch nickel steel face-hardened plate B 504½ , both supplied by the Carnegie Steel Company. The 5.5 inch plate was the port re-entrant plate which had been recently tested. The 6-inch plate had been previously used, 20 impacts for the tests of 6-inch armor-piercing projectiles having been made upon it. The 5½-inch plate was against the structure; the 6-inch plate was outside of it and toward the gun. They were lapped over each other for a distance of 4 feet 3 inches. No greater flat surface was available, previous impacts on the 6-inch plate interfering. The results obtained, however, show that this overlapping was ample for the experiment. The contact between the two plates was as good as can be looked for in actual practice. The 5.5-inch plate next the structure had its original backing of 3.5 inches of oak and 2½-inch skin plates, and was secured to the structure by three holding-in bolts. The 6-inch plate was secured against the 5½-inch plate by timbers and bolts passing through previous impacts and a vertical timber at the end where it overlapped the 5½-inch plate, thoroughly secured by bolts above and below. All the experts present agreed that the plates were well secured together.
The impact on the front or 6-inch plate was 4 feet 1½ inches from the bottom, 2 feet 5 inches from the left edge and 2 feet 8 inches from the nearest impact—that is, the impact was about the center of the superimposed portions of the plate. The angle of impact was normal. The projectile penetrated both plates, passed through about 15 inches of sand, and coming to the surface was thrown out to the right and found at a point 70 feet to the rear and 33 feet to the right of the point of impact. The point was broken off the projectile. The number of pieces found was five, the largest piece weighing 453.5 pounds; the total weight of pieces picked up, 459 pounds. The projectile was pronounced to be of fine quality.
Effect on Front Plate.—The projectile made a clean hole through the 6-inch plate, the diameter of the hole being 10 3/8 inches. The interior surface was fused. The diameter of flaking was 14 inches; diameter of back bulge, 22 inches; the height of back bulge was 3 inches, ragged, and there was a front fringe of about I inch. A number of radial and circular cracks were developed about the point of impact. A small piece was broken out of the plate toward the nearest edge.
Effect on Rear Plate.—The projectile passed through the rear plate, making a cone-shaped hole 16 inches in diameter on the side nearest to gun, 13 inches in diameter on the side furthest from the gun. The plate was dished 2 inches. The back bulge was all broken away. A through crack went from the impact to the right edge of the plate and two concentric cracks about half way around on the left side of the hole 24 to 32 inches in diameter. The backing and skin plates were badly torn by fragments of plate.
The tests were made under the direction of Lieutenant-Commander Couden, who made the following brief report of the result to the Department: “Although a comparison is difficult to make, it would seem that this combined plate was somewhat less resistant than a single plate of the same thickness. Both these plates are of most excellent quality. The 6-inch plate has received 20 impacts and demonstrated its high resisting power and excellent quality heretofore. The rear plate has shown its quality on this occasion.”
All experts who witnessed the test unite in the opinion that the superimposed plates proved much less efficient than single plates of their combined thickness, made under similar conditions and heretofore tested under equivalent specifications.
A test was made at Bethlehem during the past week of the 10-inch face-hardened armor of the battle-ships Kentucky and Kearsarge. These plates are nickel steel, double forged, and the ballistic plate was backed by 12 inches of oak and 2½-inch skin plates. Three rounds were fired, with the following results:
First Round.—Eight-inch armor-piercing shell; striking velocity, 1476 foot seconds. Plate uncracked; projectile broke up, head remaining sticking in plate; estimated penetration, 2 inches.
Second Round.—Eight-inch Holtzer armor-piercing shell; striking velocity, 1752 foot seconds. Plate uncracked; projectile broke up, head remaining sticking in plate; estimated penetration, 3 inches.
Third Round (supplemental).—Eight-inch Holtzer armor-piercing shell; striking velocity, 2078 foot seconds. Plate uncracked; projectile broke up, head remaining sticking in plate; penetration unknown.
While the tests at Indian Head of the two thin plates can hardly be compared with those at Bethlehem of the 10-inch plate, yet in whatever relation exists between the two the superiority of the thick plate is claimed by experts to be clearly apparent.—Iron Age.
At the Indian Head Proving Grounds a charge of 300 pounds of guncotton was recently exploded between two ££-inch iron plates, which were parallel and fifty feet apart; one was 15 and the other 35 feet from the explosive. It was expected that the detonation would injure the plates, but it did not A great hole, however, was blown into the ground. It seems to be settled that high explosives must be nearer than 15 feet to injure a ship.
Experiment with Gathmann Shell.
Experiments which the Bureau of Ordnance of the Navy have been making at the Indian Head Proving Grounds with a shell intended to permit the use of high explosives in ordinary guns came to a somewhat disastrous end on Wednesday, June I, by the bursting of the shell in the gun, which in turn was torn to pieces with a tremendous explosion. The witnesses of the trial escaped unharmed, though pieces of the burst gun and shell fell around the tug upon which the ordnance officers were watching the test. The officer who discharged the gun escaped only because he had sheltered himself behind an embankment instead of resorting to the usual corner of the bomb-proof, where the force of the explosion was so great that it collapsed a small wooden building used to shelter the instruments. The shell was a Gathmann shell, loaded with over 300 pounds of gun-cotton, and it is supposed that it was made to withstand the shock of the explosion of the powder charge in the gun, which in this case was much less than usual, the pressure being about three tons instead of 15 tons to the square inch. The gun destroyed was jacketed tube, intended for a 13-inch gun, but so far only bored out as a 12-inch tube. The ordnance officers have never been satisfied as to the possibility of using gun-cotton in this way, but made the experiment by direction of Congress, which set aside an appropriation for the purpose.
Test of Jovite in Projectiles, and of Corn Pith in Cofferdams.
Important information in regard to three features of naval ordnance and construction was obtained to-day, June 12, as a result of tests made at the Indian Head Proving Grounds.
In the first place the officials demonstrated that jovite, the new high explosive, when loaded in a service armor-piercing projectile, could be safely fired from a high power gun through Harveyized armor, and would explode in the rear of the target. For the first time since the adoption of semi-armor piercing shells in the navy, one of 10 inches in caliber was fired through a Harveyized plate, the thickness of which was slightly greater than half the shell’s caliber, and exploded in the rear. In addition, the trials to-day showed the ability of corn pith when placed back of armor to keep out the water, provided the armor and structure behind it are not greatly overmatched by the penetrating projectile.
The tests were made as the result of a recommendation by Chief Naval Constructor Hichborn that two cofferdams, one protected by 4-inch armor and the other by 5½-inch armor, be tested in order to ascertain whether or not corn pith could be depended upon to prevent water from entering a ship through a shot hole.
The cofferdam protected by 4-inch armor was first fired at with a 6-inch capped armor-piercing projectile with a velocity of 1800 feet per second. It made a clean hole in the armor, perforated the entire structure and the butt ten feet in the rear, and was picked up seventy feet away in excellent condition. The size of the hole in the rear of the cofferdam was about ten inches, through which very little water escaped.
Then a six-inch armor-piercing projectile, containing jovite and fused, was fired at the target with a velocity of 1865 feet per second. It was desired by the authorities that the shell should explode in the cofferdam. The shell failed to do as anticipated, but perforated the target and exploded fifteen feet from the face of the target. This is the first time an armor-piercing projectile has been safely exploded, powder failing to take such action.
The men on duty at the proving grounds hunted for some of the pieces of the projectile, but were unsuccessful. This showed that the projectile had been blown into small pieces, and had it exploded on shipboard the result would have been disastrous. No cracks appeared in the armor.
After these two shots were fired a box-like arrangement fitted in front of the four-inch plate was closed and water poured in. It was found that the water leaked from the shot holes in the rear of the target at the rate of about sixteen gallons per minute.
Attention was then directed to the target protected by five and a half inch armor. A 10-inch semi-armor-piercing shell was loaded with eighteen pounds of black powder and fired at the target with a velocity of 1650 feet per second. The shell perforated the target, practically demolishing the rear of the cofferdam and exploded just on the edge of the butt. The hole in the rear of the cofferdam was about four feet in diameter. —New York Herald.
[England.]
Trial of Vickers Six-inch Armor Plate.
We have succeeded in obtaining the following authentic details of the remarkably successful trial of the Vickers plate tested on board the Nettle at Portsmouth on the 19th of March last. The dimensions of the plate were 8 feet by 6 feet by 6 inches. It contained among other elements, 4 per cent, of nickel. There was originally a hair line about the center of the plate. The mounting and backing were as usual, the thickness at the top and bottom was 4 feet 10 inches, and at the center 5 feet 10 inches. The plate was secured by eight bolts.
The attack was made entirely with 6-inch Holtzer armor-piercing steel projectiles, fired with a charge of 48 pounds of EXE powder, which gave a muzzle velocity of about i960 foot seconds. The striking velocity was practically the same, the plate being fixed at only a few feet along the deck.
The first shot was delivered near the right-hand bottom corner. The projectile broke up, leaving the point embedded, and apparently fused into the plate. When the point was jarred out by the 6th shot the depth of indent was found to be 2¼ inches. There was slight scaling round the point of impact. At the back was a bulge 1 3/8 inch high, and 12 inches by 12 inches in area, with one crack. There may be noticed on the face certain white radiating splashes. These always seem to indicate complete disintegration of the shot. In former days they furnished evidence that the attacking projectile had been of chilled iron; but latterly, since the faces of plates have been specially hardened, steel projectiles have sometimes broken up in such a way as to exhibit these splashes.
The second round was delivered near the left-hand bottom corner. The result closely resembled that of the first round. Apparently, judging from the front, a larger part of the shot’s point was embedded. There is more scaling, but no splash. The shot, however, seems to have flattened more, the bulge at the back being only ¾ inch in height, and having no crack in it.
The third round struck towards the left top corner, the shot breaking up in much the same way as before. There was a little more scaling off of the surface, and a hair crack was developed from point 2 to the left of the plate. After the point of this shot jarred out, the depth of the injury was found to be 1¾ inches. The bulge at the back was 1 inch high and 13 inches by 13 inches across.
Round 4 struck the near right top corner. The general result was as before; the shot spread as much as 2, but more of the mass lodged probably, as the bulge at the back was 1 1/8 inch high and 14 inches by 14 inches across. There was rather more scaling round the shot, and the hair crack from 2 was rather more developed.
Round 5 was delivered near the center. The effect was again much as before, the shot breaking up in the same way. It was after this round that the point of No. 3 was dislodged, leaving the rest of the lodged portion of the head in a ring round it. The bulge at the back was 1 inch high, and both its horizontal and vertical cross measurements 14 inches.
This completed the proof test, which had been most successful in all respects. At the request of Messrs. Vickers a sixth shot was planted in the plate between rounds 5, 2, and I, that is, a little below the center. The same general effects were again produced, though they were rather greater, the surface of the plate was “driven in locally,” and local cracking produced with irregular scaling about 2 inches deep, forming a sort of crater between rounds 2 and 6. The point of No. 1 was jarred out by this shot. The bulge at the back was 1½ inches high, and measured across 13 inches and 14 inches, and there was a crack made. Altogether, the slightly increased effect of this round only shows what we well know, that the molecular action in the metal of the plate extends further than could be seen from inspection.
As to ballistic results, the velocity is not measured, but is approximately i960. This implies a striking energy of about 2665 foot tons, and a perforation by Tresidder’s formula of about 13.45 inches of iron, or 2.24 times the thickness of the actual plate. Supposing the plate to weigh 5.275 tons, which is what we calculate from its dimensions, the energy per ton of each blow is 505 foot tons, and the total of the six blows 3030 foot tons per ton. This shows a more severe test than plates of this thickness have been hitherto subjected to. On these thin plates the shock of resisting strain never comes to a large amount, on account of their area being large in proportion to their thickness, but, as pointed out in the case of the Cammell and Brown plates similarly tried, the perforation attack defeated, works out very high. We wish, however, in order to enable a complete comparison to be made with foreign plates, one or more Wheeler-Sterling projectiles could be fired in our Nettle tests. As they are now supplied by Elswick, this might be easily done. We would conclude by congratulating first Messrs. Vickers, and then not only our three Sheffield makers, but England as a nation, on the excellence of the 6-inch plates now being delivered. This Vickers plate we are specially glad to describe, because it had an extra round fired at it, and is a singularly excellent plate.—The Engineer.
SHIPS OF WAR.
[United States.]
Trial of U. S. S. Iowa.
The U. S. battle-ship Iowa, constructed by the Messrs. Cramps, at Philadelphia, was given her official trial in Long Island Sound over the Cape Ann course on April 6, the weather conditions being most favorable. The stations were 6.6 miles apart, and the course was thirty-three miles north-northeast from the first station, about five miles southeast of Thatcher’s Island to the sixth station, about a mile to the eastward of Boone Island buoy and return. The elapsed time for the first half was 1:57:23. Average speed, 16.873 knots; for second half, 1:55:24; average speed, 17.27. Average speed for the entire distance, 17 knots; elapsed time, 3:52:47.
The official speed as subsequently reported by the trial board, with all allowances for tides and other interfering conditions, was 17.871 knots.
The boilers showed an average pressure of 152 pounds, all that could be expected with the inch of air pressure allowed in the closed fire-rooms. Both engines ran with remarkable uniformity, the revolutions of the screws not falling below hi per minute nor rising above 113½, and averaging 112 for the run.
The speed was also remarkably uniform between the several marks along the course, and shows that the vessel scarcely made any spurts, but kept close to her best work all the time, the variations being almost wholly due to the changing depth of the water.
After the trial her turning powers were tried. She answered her helm readily, and showed the possibility of turning a circle of less than 400 yards. She was also very steady in trimming, and her greatest angle of heel was only two degrees. The absence of vibration, even when the ship was driven at her highest speed, was very marked. In fact, the vibration could hardly be felt except at the extreme bow and stern.
Holland Submarine Boat.
The Holland submarine torpedo-boat was launched successfully from the yards of Mr. Lewis Nixon, at Elizabethport, N. J., on May 17.
The boat was towed into the adjoining slip, where she will remain until her private trial trip, after which she will be sent to Washington.
The date of her private trial trip has not been made public. An official public test will be made soon, Mr. Holland said, when an engineer officer from each government will be allowed on board. Mr. Holland, speaking of his boat just launched, was quoted as follows:
“The craft is 53 feet 3 inches long, with a diameter of 10 feet 3 inches amidships, a 4-foot screw protecting extension, and the moulded diameter is 10 feet 3 inches. She can travel under water 8 hours at 8 knots, and 10 knots on the surface. It will take barely one minute to submerge the boat, and not much longer to raise it to the surface of the water.
“The armament consists of three torpedo-tubes, one at the upper bow of the boat being an aerial torpedo thrower, with a range of one mile. Six projectiles weighing 180 pounds, with charges of 100 pounds of explosives, are to be stored for this gun.
“Almost directly beneath the torpedo-thrower is an expulsion tube for Whitehead torpedoes. Only three of these torpedoes will be carried, as each one weighs 850 pounds. At the stern of the boat is a submarine gun which, with a 100-pound charge of explosive, can hurl a 400-pound projectile 100 yards or more under the water. Five of these projectiles will be carried. The craft will be worked by six men.
“Now, I have this boat and one somewhat similar, which is being built at Baltimore. The latter boat is much longer than this one, and for that one reason more interest is centered in it.”
TRIAL TRIPS OF GUNBOATS.
The Wilmington and Helena.
The gunboat Wilmington, built by the Newport News Shipbuilding & Dry Dock Company, made a very successful trial trip on March 27. The course was in Long Island Sound, from Horton’s Point to Cornfield lightship and return, a distance of twice 27 knots. She drew 8 feet 2 inches forward and 9 feet 1 inch aft. The engines made a mean of 267 revolutions per minute; the maximum was 277. Steam pressure was 189 pounds. The contract speed was to be 13 knots, but she made 15.07 knots, earning a bonus of $41,512.
The Helena eclipsed the performance of the Wilmington, making the official speed of 15.49 knots per hour. She carried 180 pounds of steam and her engines made an average of 279 revolutions on the official run.
The Annapolis.
The new gunboat Annapolis, which is the first to be completed of the six composite hull boats ordered by the Government early in 1896, was given its official trial of four hours at full speed on Long Island Sound on April 22. This gunboat is notable as being the first U. S. Government vessel of large size to be fitted with boilers of the water-tube type exclusively. Other vessels have been built within a few years ij which the Scotch type and the water-tube boilers have both been used in connection with each other.
The Annapolis was built at the Crescent Ship Yard, Louis Nixon, Manager, Elizabethport, N. J., and the boilers were furnished by the Babcock & Wilcox Co. of New York City, whose works are also at Elizabethport. The same type of boiler has also been adopted for the gunboat Marietta.
In this boiler the water tubes are all straight, placed at an angle of 15° with the horizontal, and expanded at each end into forged steel headers. Openings are provided in these headers opposite the ends of the tubes, through which a thorough examination of each tube may be made, and the tubes cleaned and renewed when necessary. By means of a steam jet inserted between the headers all deposits of soot may be removed from the exterior of the tubes. Surmounting the sections of tubes is a steam and water drum 42 inches diameter and 10 feet long; all openings leading into and out of drum are 4 inches diameter. Steam to 200 pounds pressure can be raised from cold water in half an hour, this being a most important feature in boilers for a war-ship. The boilers are designed for a working pressure of 250 pounds.
The principal dimensions of the Annapolis and of its steam equipment are as follows:
Length, 204 feet; width, 36 feet; depth, 23 feet 3½ inches; displacement on a draft of 12 feet, 1000 tons; boilers, two, each 94 square feet of grate and 3600 square feet of heating surface; ratio of grate to heating surface, 1 to 38.3; engine, triple expansion, with cylinders 15, 24½ and 40 inches diameter, 28 inches stroke; contract speed of vessel, 12 knots with 800 IHP. The builder’s trial showed that 900 IHP could be developed under natural draft, with a short funnel.
On the official trial forced draft in the ash pit was used, each boiler being supplied by air from independent Sturtevant fans, the average air pressure in the ash pit being limited to 1 inch of water.
During the 4-hour trial the steam pressure averaged 226 pounds per square inch, the minimum being 218 and the maximum 240 pounds. The draft pressure in the ash pit averaged 0.90 inch on the port side and 0.91 inch on the starboard side. The speed trial over a measured course of 48 knots, marked by nine stake boats, gave a speed in the eight divisions of the course ranging from 12.7 to 14.18 knots per hour, averaging 13.43 knots.
The maximum IHP developed by the main engine was 1400, the average being 1320, at 147 revolutions per minute. The collective IHP will average about 1360. Dividing 1320 IHP into 3600 square feet heating surface gives one IHP for each 2.73 sq. ft. of heating surface. Dividing it by 94 square feet of grate gives 14 IHP per square feet of grate. During the test under forced draft the smokestack did not become hot enough to burn the paint off it.
At the end of the test of four hours at full speed the helm was put hard to port and to starboard without reducing speed, and the little vessel made circles with a diameter of 400 feet. In turning she heeled only 3.5 degrees.
The Nashville.
The new light-draft United States gunboat Nashville made her official trial on Long Island Sound on May 4, and earned for her builders, the Newport News Shipbuilding and Dry Dock Company, a bonus of near $60,000, her speed greatly exceeding that which was guaranteed, and for which the Government will reward her constructors. Her average speed throughout her trip was 16.7 knots, while but 14 knots was required. The course was laid from Stratford Light to Horton’s Point, a distance of 30 miles in a straight line, and return. There were six stake boats, consisting of the tugs Leyden and Narkeeta, the lighthouse tender Cactus, and the torpedo-boats Stiletto, Porter, and Ericsson, which were anchored at distances of five miles along the course. The total time consumed in the run was three hours and forty-seven minutes. After the speed test the gunboat was put through several tests to show her seaworthiness, all of which were successful.
The Nashville is schooner-rigged, and is interesting because of her peculiar machinery arrangements. She has twin screws and two sets of quadruple expansion engines. The cylinders of these are arranged in fore and aft lines, with the low pressures towards the bow. The purpose is to disconnect these big cylinders by a shaft coupling when the vessel is on ordinary cruises, making the engines triple expansion, and as thus arranged they can be worked with small consumption of coal at about eight knots speed. By coupling the low-pressure cylinders with the others the speed may be run up to fourteen knots, though at the expense of much more coal. At cruising speeds an economy closely approximate to that of careful merchant steamers is expected. Her smoke-pipes are very tall, reaching almost to the top of her masts.
Aside from these novel machinery arrangements, the features of the Nashville are as follows: Length, 220 feet; breadth, 38 feet 3 inches; displacement, 1371 tons; complement, 150 men; battery, four rapid-fire 4-inch rifles on the main deck, four of the same in armored sponsons on the gun deck, four 6-pounder Hotchkiss guns and a number of i-pounder and Gatling guns.—Seaboard.
The Wheeling.
The official trial trip of the gunboat Wheeling took place on Saturday, May 29, on a twelve-mile course in San Francisco bay. She ran four hours at 231.4 revolutions a minute, with a steam pressure of 180 pounds, giving a speed of 12.75 knots per hour. Her working was entirely satisfactory, less coal per horse-power being required than by her sister ship, the Marietta, and the engine and fire-rooms were cooler.
The Vicksburg.
The gunboat Vicksburg, sister ship of the Newport, had her official trial trip on May 29 off Bath, Me., and developed a speed of 12.68 knots an hour, which is about four-tenths of a knot better than the Newport made over the same course.
Trial Trips of the Porter.
The torpedo-boat Porter withstood a very severe test June 10, with the Board of Inspection and Survey on board of her, running her final trial before acceptance by the Government. She started at six o’clock in the morning from the foot of East Twenty-sixth street and returned to the same wharf at half-past six o’clock in the evening, having steamed around Long Island in twelve and one-half hours. She averaged about twenty knots for the run and varied from fifteen to thirty knots speed in both rough and smooth water.
Probably no other torpedo-boat ever had such a severe test, and certainly the Porter came through it splendidly, for she clearly demonstrated that she could make much more speed than she was contracted to make. This trial, however, was not for speed, and the steam pressure was limited to 200 pounds, instead of the 225 pounds that her boilers may carry.
She also demonstrated that her water-tube boilers can steam with salt water in them, though it was thought not advisable to carry more than one hundred pounds of steam under these circumstances.
Following are the particulars of her run: At six o’clock she left the wharf under one boiler, making fifteen knots up the East river, under the auxiliary stop valves. The Porter has two sets of stop valves, the main valve being a twelve-inch and the auxiliary stop being one and a half inches in diameter. At forty-four minutes past six she connected a second boiler, and for a time made twenty knots with 160 pounds of steam and one-quarter of an inch of air pressure forced draught.
At ten minutes past eight she opened the main stops and made twenty- five knots, with one inch of air pressure and 150 pounds of steam.
At half-past nine she connected the third boiler, and for fifty minutes, between Stratford Shoal and Falkner’s, made thirty knots, with 200 pounds of steam and one inch of air pressure.
At the end of another fifty minutes, being out of sight of suitable ranges to get the actual speed for an hour, one boiler was cut out, and the Porter proceeded through Plum Gut and around Montauk Point at twenty-one knots, heading for Sandy Hook Lightship at half-past eleven, with Montauk light abeam.
A stiff breeze was blowing, with quite a heavy sea and white-caps.
To Fire Island she averaged eighteen knots, when a leak was developed in the main feed pipe which could not be controlled, so that all the fresh water was lost, and the vessel was obliged to drop to one boiler and use salt water therein, in addition to the evaporators and distillers.
The leak having been repaired, the Porter left the navy yard at seven o’clock, June n, to complete the final trial for acceptance. She first went over to Communipaw for a small supply of coal, and at nine o’clock went alongside the dock at East Twenty-sixth street, where the Board of Inspection and Survey boarded her. She then steamed down to the lower bay, where the tests took place. These tests were eminently satisfactory.
All the torpedo-tubes were tested, torpedoes being successfully fired from each of the three tubes at a boat sent out from the Porter as a target. The turning circle of the Porter was determined with both engines going ahead at full speed, making seventeen knots, with the helm hard over. The diameter of her circle under these conditions was found to be about 1000 feet, a very small area for such speed.
Then the little boat squared away, and while going ahead at seventeen knots the engines were suddenly reversed. She stopped almost instantly, and was going full speed astern before she had gone one-half her length. Then the experiment was reversed, and the result astonished even those who have served in her since her commission. The little craft shook herself, stopped, and went ahead in less than one-quarter of her own length.
The time necessary to shift the helm by steam, from hard a-port to hard a-starboard, and the reverse, while going ahead at full speed, was found to be six seconds, and the same time is required for the return to hard a-port.
It was noted with curiosity that the Porter heels toward the center of her turning circle when the helm is put over. Other steam craft heel the other way under similar conditions. The hand-steering gear was tested from both forward and aft and found to be most satisfactory.
During the entire run of the day only one boiler was in use, and that one was the boiler in which salt water had been used during the Porter’s run around Long Island on Thursday. This boiler worked well, and a careful examination shows no bad effects resulting from the use of the salt water.—New York Herald.
[Chili.]
The O’Higgins.
The Chilian cruiser O’Higgins was launched from the yard of Sir W. G. Armstrong, Whitworth & Co., Elswick, on May 17. The vessel is named after an Irishman who was the founder of the Chilian Navy, and ex-President Admiral Montt spoke of him also as the founder of the republic. The principal dimensions of the cruiser are: Length, 412 feet; breadth, 62 feet 9 inches; mean draft, 22 feet; displacement, 8500 tons. Her armament will consist of four 8-inch, ten 6-inch, four 4.7-inch, ten 12-pounders, ten 6-pounder quick-firing guns, four machine-guns, and three torpedo-tubes. The total coal capacity is 1200 tons, and the guaranteed speed is 21¼ knots.—United Service Gazette.
[England.]
The Europa.
H. M. S. Europa was launched March 20 at the Clydebank Shipbuilding Company’s works. She is a first-class cruiser of the Diadem class, of 11,000 tons displacement, 435 feet length, 69 feet beam, and 25 feet 3 inches mean draft. Two sets of triple-expansion engines to develop 12,500 I. H. P. at natural draft, 16,500 with forced draft, giving a maximum speed of 21 knots. Coal capacity 1000 tons at normal draft; total capacity, 2000 tons. These vessels carry batteries of sixteen 6-inch and fourteen 12-pdr. R. F. guns, besides 12 3-pdrs. and numerous machine-guns. There are four funnels and two military masts.
The Pyramus.
H. M. third-class cruiser Pyramus, of Pelorus type, was successfully floated out of the Jarrow dock on May 15.
Launches and Trial Trips of Destroyers.
The destroyer Chamois, on May 7, during her full speed preliminary run, maintained for three hours a mean speed of 30.336 knots with 386 revolutions per minute.
The Whiting, on her official trial, May 10, maintained for three hours a mean speed of 30.167 knots with 392.7 revolutions per minute. At the latter portion of the trial, when the tide was stronger and the boat had become somewhat lighter, a speed of 32.8 knots was attained.
The Earnest, on her official trial, May 24, maintain for three hours a mean speed of 30.12 knots.
The Griffon, on her three hours’ coal consumption trial on May 25, maintained 30.02 knots. On her full-power trials, June 1, six runs over the measured mile resulted in a mean speed of 30.12 knots.
The Flirt was launched at Jarrow, May 22, and the Wolf at Birkenhead, June 2.
The Turbinia.
A further series of trials of the torpedo-boat Turbinia began on April 9th by Professor Ewing, F. R. S., and concluded on Wednesday, April 14th. The full speed trials were taken on Saturday, when the mean speed of 32¾ knots on the measured mile was realized. On several of the days the sea was rough, but throughout there was no perceptible racing of the screws, and the engines worked with perfect smoothness and a complete absence of vibration. On Wednesday the 14th the turning and circling tests were satisfactorily carried out, and a test for acceleration showed that the boat could be started from rest to 28½ knots speed in 20 seconds and brought to rest from this speed in 35 seconds.—Engineering.
[France.]
The Jena.
The dockyard authorities at Brest have received orders to proceed with the construction of the new battle-ship, designated in the estimates as A3, which is to be called the Jena. She will be laid down on the slip from which the Gaulois was launched last autumn, and will be the largest ship yet built at this yard. She will be somewhat larger than the Gaulois and her sisters, the Charlemagne and St. Louis, as the following comparison between the dimensions of the ships will show:
[TABLE]
The ship will have three screws, steam being provided by twenty Belleville boilers, which will be fitted to burn either coal or petroleum. If necessary, the ship will be able to carry 1100 tons of coal, which will give her an extra radius of action of 1800 miles, or 7000 miles in all. Protection will be afforded by a complete water-line armor belt, with light armor over the other works, and two armored decks, but the thickness of the armor has not yet been settled. The armament will consist of four 30.5-centimeter (12-inch) guns, in two turrets, one forward and one aft; in a central battery between the turrets will be eight 16-centimeter (6.3- inch) Q. F. guns, four firing from the beam to right ahead, and the other four from right astern to abeam; above, on the superstructure, will be eight 10-centimeter (3.9-inch) Q. F. guns similarly disposed for the end-on to beam fire; there will also be sixteen 3-pounder, five 1.5-pounder Q. F. guns, and thirteen i-inch magazine guns, with six torpedo-tubes.
Lavoisier.
The third-class cruiser Lavoisier was launched at Rochefort on 18th April; her dimensions are as follows: Length, 326 feet 8 inches; beam, 35 feet 8 inches, with a displacement of 2300 tons. Her engines are to develop 6600 I. H. P., and her estimated speed will be 20 knots. Her armament is to consist of four 14-centimeter (5.5-inch), six 10-centimeter (3.9-inch), eight 3-pounder, and six i-pounder guns, all Q. F., with four torpedo-tubes.—Journal of Royal United Service Institution.
[Germany.]
The Victoria Luise and the Hertha.
The second-class cruiser L was launched March 29 at the works of the Weser Company, and was christened Victoria Luise. The sister ship, K, christened Hertha, was launched April 14 at the Vulcan dockyard, Stettin. The third vessel of this class, Ersatz Freya, is still on the ways.
These cruisers are built entirely of steel, 344 feet long, 57 feet extreme beam, with a mean draft of 20½ feet and a displacement of 5650 tons. They are driven by three screws, the three separate engines giving a total of 10,000 indicated horse-power, capable of producing a speed of 18½ knots. The coal capacity is 500 tons at normal draft. The armament will consist of two 8.2-inch Q- F. guns, one forward and one aft in 4-inch armored hooded barbettes, eight 6-inch Q. F. guns, four on the main deck in 4-inch armored casemates, two with an arc of training from right ahead to 35° abaft the beam, and two with an arc of training from right astern to 35° before the beam, and the other four on the upper deck. Also in armored casemates ten 3.4-inch Q. F. guns (20-pounders), ten 3-pounder Q. F. guns, and four machine-guns with three submerged torpedo-tubes, one in the stern and one on each beam. There is a 4-inch armored deck, and the heavier guns have separate armored ammunition tubes, all the armor being of Krupp’s nickel-hardened steel. The total complement will be 439 officers and men.
Station Cruiser G.
The new station cruiser G is to be built at the Germania yard at Kiel, which was lately taken over by the Krupp firm at Essen. Like the earlier fourth-class cruisers, the new vessel is intended for foreign service, but it is is of an improved type, her dimensions being as follows: Length, 325 feet; beam, 36 feet; mean draft, 14 feet, with a displacement of about 2600 tons. The hull will be of steel, wood sheathed; there will be a two-inch armored deck and an armored conning tower. The engines are to develop 6000 I. H. P., giving a speed of 20 knots. It is proposed to lay down four vessels of this type as soon as the money can be voted for them.
[Italy.]
St. Bon.
The battle-ship St. Bon, named after Admiral St. Bon, was successfully launched on May 29th. She is a sister ship of the Emanuele Filiberto and was built at the Royal Dockyard at Venice. Her principal dimensions are as follows: Length, 345 feet; breadth, 70 feet; mean draft, 24 feet 9 inches; displacement, 9800 tons. The two sets of vertical triple expansion engines were built by the Ansaldo firm, and with 13,500 indicated horse-power will give a speed of 18 knots. There are 12 cylindric boilers with 36 furnaces. The total coal capacity is 1000 tons, given a steaming radius of 7500 miles at 10 knots; besides this, liquid fuel can be carried in the double bottoms. There is a complete armor belt along the waterline of Terni nickel steel plates varying in thickness from 4 to 9.8 inches, the armor of the redoubt and barbettes 9.8 inches; the battery is protected by 5.9 inches. The armament consists of four 10-inch breech- loading rifles, two in the forward barbette and two aft, eight 6-inch R. F. guns in the redoubt, each gun being further protected by steel splinter bulkheads, eight 4.7-inch R. F. guns, also six 57 mm. guns, as well as numerous rapid-fire guns of smaller caliber. All these guns were built at the Armstrong establishment at Pozzuoli and at the Spezia arsenal. There are one stem and four broadside torpedo-tubes. The complement will be six hundred men and officers. In launching this ship the custom of breaking a bottle of wine over the bows was departed from. The Crown Princess Helen followed an old Venetian custom, securing to the ship a gilded bronze ring about 5½inches diameter, engraved with a suitable inscription, by means of a silk ribbon of such a length that during the launching this ring would touch the water first. The ring will be preserved in the Royal Arsenal.
Auxiliary Cruisers.
The following-named vessels are destined as auxiliary cruisers in case of war: The Nord America, length, 445 feet; displacement, 4826 tons; Vittoria, length, 400 feet; 4300 tons; 4500 indicated horse-power; Duca di Galliera and Duchessa di Genova of the Veloce Company; the Regina Margherita, length, 375 feet, 4000 tons, 3687 indicated horse-power; Elettrico, Candia and Malta, all of the Company Navigozione generale. The vessels are each to be armed with light rapid-fire batteries.
[Japan.]
Trials of the Fuji.
The battle-ship Fuji, built at the Thames Ironworks, on her first trials of six hours’ steaming, averaged 16.937 knots with 10,200 indicated horse-power. The later trials for full speed gave a mean speed of 18.655 knots with 14,100 horse-power, the vessel being down to her deep-load draft. The steering gear, supplied by Davis & Co., enabled the helm to be put from hard-over to hard-over in 16 seconds.
The Latest Japanese Battle-ship.
Within the past two months the Thames Ironworks and Shipbuilding Company have contracted to build for the Imperial Japanese Government a still larger and more powerful battle-ship than the Fuji, a vessel, in fact, which in her offensive and defensive powers will constitute one of the most formidable armor-clads yet constructed for any navy.
As the displacement of the largest armor-clads of the British Navy— those of the Majestic class—when fully equipped, but without their coal— 900 tons—on board is only 14,000 tons, the new Japanese vessel, which is to have a displacement of 14,850 tons, with a coal capacity of 700, will have 150 tons more weight in her hull than any of the battle-ships of the class mentioned.
The dimensions of the new vessel are to be: Length between perpendiculars, 400 feet; over all, 438 feet; breadth, 75 feet 6 inches; water draft, 27 feet 3 inches, and displacement as given above, viz., 14,850 tons. She will be constructed on the double-bottomed system, with water-tight flats at her ends, practically making her double-bottomed throughout. Her side protection will consist of a lower armor belt, made of Harveyed nickel steel, carried from stem to stern, 8 feet 2 inches deep, and 9 inches thick throughout the length of the engine, boiler and magazine spaces, tapering to 4 inches at the ends. Above the lower armor belt, and for a length of 250 feet amidships—which length encloses the two barbettes for the big guns—an additional belt of 6-inch armor is to be worked to the height of the main deck. Rising from the lower edge of the main armor belt to a height on the middle line of the ship of about 3 feet above the water-line, and extending from stem to stern, there will be a complete armor deck of steel 3 inches thick on the flat part and 5 inches on the slopes, tapering at the ends. From this deck, and at either end of the 250 feet armor belt, which forms the sides of and is equal to the length of the citadel, the two barbettes, which are to be circular in form and protected by 14-inch armor, rise through the main deck, and continue to a height of 4 feet above the upper deck. A curved thwart- ships bulkhead of steel 14 inches thick will be worked from above the protective deck to the height of the main deck, and between the main and upper decks steel screen bulkheads will also be fitted, extending from the barbettes to the ship’s sides.
The armament of the new battle-ship will consist of four 12-inch 40- caliber breech-loading guns, two being in the forward and two in the after barbette; fourteen 6-inch 40-caliber quick-firing guns in armored casemates of 6-inch Harveyed nickel steel, eight being on the main deck and six on the upper deck, the casemates being made water-tight on their inner and outer sides, thus serving to protect the gun crews from explosive shells entering between decks, and preventing water finding its way there should a gun port become damaged. Supplementing the above detailed armament there are to be twenty 12-pounder quick-firing guns placed on the upper deck, eight 47-millimeter guns on the upper and main decks and military tops, and four similar sized guns on the bridges. There will also be fitted five 18-inch torpedo ejectors, one in the stem above water and four submerged, the usual torpedo-nets completing the defensive gear.
The steering of the vessel will be effected by steering gear, on Cameron’s self-regulating principle, worked by steam-steering engines in duplicate, as a preventive in case of the possible failure of one set, the controlling gear being on Messrs. Brown’s telemotor principle, controlling the helm from pilot house, forward bridge, after pilot house and bridge, and from the protective deck forward.
The propelling machinery of the new ship, which will be of 14,500 indicated horse-power, will consist of two complete sets—in separate engine- rooms—of three-cylinder triple-expansion twin-screw engines, the diameters of the cylinders being 34 inches, 53 inches, and 84 inches for high, intermediate, and low pressure respectively, with a piston stroke of 48 inches. They will be supplied with steam by twenty-five of the latest type of Belleville boilers, having an aggregate heating surface of 40,000 square feet.
The ship will be lighted throughout by electricity, the installation consisting of four sets of combined engines and dynamos—three of 400 amperes and 80 volts each and one of 200 amperes and 80 volts, the latter of the direct current type. Nine hundred incandescent lamps of 16-candle power each will be provided for lighting saloons and cabins, store, engine, and boiler-rooms, magazines and coal bunkers, etc. Six search-lights, each of 20,000 candle-power, having mirrors 24 inches in diameter, will also be provided.
The complement of boats carried by the new battle-ships will be fourteen, and will include two 50-feet vedette boats, fitted with the Thames Ironworks water-tube boilers; one 42-foot launch, and one 30-foot steam pinnace, each of which will carry Whitehead torpedoes, and be fitted for mining and countermining.
The ship will have a complement of men and officers to the number of 741, which will include an admiral and thirty-eight officers. The contract time for the completion of the vessel has been fixed at twenty-seven months.—Engineer.
The Japanese Government have entered into a contract with Messrs. Yarrow & Co., Limited, of Poplar, for the construction of four torpedo- boat destroyers of 31 knots speed.
[Norway.]
Tordenskjold.
From the Walker shipyard of Sir W. G. Armstrong, Whitworth & Co., there was launched on the 18th of March, for the Norwegian navy, the armor-clad ship Tordenskjold. The vessel is a sister ship of the Harald Harfaagre, which was launched on January 4 last from the same yard. There is an armor belt 7 inches to 4 inches in thickness; the conning tower is protected with 6-inch armor plate, and she has a ram. The armament, differing somewhat from that of her sister ship, will consist of two 8-inch quick-firing guns, six 4.7-inch quick-firing guns, six 12-pounder quick-firing guns, and six 1½-pounder quick-firing guns.
[Russia.]
Great activity continues to reign in all the Russian dockyards. At Nicolaieff, a second-class battle-ship, a sister ship to the Rotislav and Sissoi Velikie, of 8800 tons displacement, has been laid down. In addition, two first-class battle-ships of 12,480 tons are to be commenced, of which one is to be ready for launching next year, and the second in 1900.
The construction of the battle-ships Poltava, Petropavlovsk and Sevastopol, each of 10,960 tons, is rapidly approaching completion, and the armored coast-defense vessels Apraxin, of 4126 tons, and the gunboat Khrabry, of 1500 tons, will be shortly ready for sea.
At the New Admiralty Dockyard, St. Petersburg, the squadron battleship Osliaba, of 12,840 tons, 14,500 horse-power, and 15.5 knots; the first-class cruiser Aurora, of 6630 tons, 12,000 horse-power, and 21 knots, are nearly ready; the gunboat Gilyak, of 810 tons, and an armored coast-defense vessel of 4126 tons and 5250 horse-power, are building. At the Galierny Ostrov, the ocean cruisers Diana and Pallada, each of 6630 tons, 12,000 horse-power, and 21 knots. At the Baltic Works, the squadron battle-ship Pereswiet, of 12,480 tons, 14,500 horse-power; in France, the cruiser Svetlana, of 3828 tons, 9000 horse-power, and 20 knots. Besides the aforementioned vessels, there are also building in the Baltic two torpedo-cruisers to be named Abrek and X, and fifteen torpedo-boats.
The old armored battery Netronj-Menia is to receive new boilers and be fitted for petroleum fuel. Two new sea-going torpedo-boats, Nos. 133 and 134, have completed their trials off Cronstadt; they averaged a speed of 24.5 knots, and are fitted with Du Temple water-tube boilers. These boats are two out of ten constructed by the Moscow Company on the Neva; two other larger boats, 180 feet long, have been ordered at the Creighton Works at Abo. Further experiments with the Masut (a petroleum mixture) fuel have been carried out in the first-class torpedo-boat Viborg, and as a result all torpedo-boats fitted with locomotive boilers are to be fitted to consume this fuel. Torpedo-boats with water-tube boilers have not as yet been so fitted, but in all the new boats the necessary arrangements are to be made.
The new first-class battle-ship Tri Sviatitelia has undergone her twelve hours’ full speed trial, which was completely successful. The engines worked smoothly throughout, developing considerably more than the contract horse-power, and gave the ship a speed of 18 knots instead of 16, for which the vessel was designed. The engines were built by Messrs. Humphrys, Tennant & Co., of Deptford, who have built the engines for so many of the Russian ships.
[Spain.]
OSADA.
The Clydebank Engineering and Shipbuilding Company, Limited, on March 16 launched a twin-screw torpedo-boat destroyer named the Osado, constructed for the Spanish Government. The Clydebank Company some time ago received orders to build for the Spanish Government a number of vessels of this class, and recently they delivered the Furor and Terror, after they had gone through speed trials very satisfactorily. The vessel now launched will be similar to the Furor and Terror, and will carry the same armament, but the tonnage will be somewhat greater, and she is to steam two knots faster. While resembling in appearance the destroyers built at Clydebank for the British Government, these vessels have some necessary modifications in arrangements and fittings, principally with the view to making them suitable for service in very hot climates.—Engineering.
The New Cruiser Rio De La Plata.
The Spanish residents of Rio De La Plata have determined as a token of their loyalty to and love for Spanish Government with a ship-of-war. Her name is to be Rio De La Plata, and she is to be built at the Forges et Chantiers Works. She is to be a cruiser of 1750 tons displacement, to make a speed of 16½ knots natural draft and 21 knots with forced draft. The triple-expansion engines to develop 7100 horse-power, steam to be furnished by four Normand boilers. The coal capacity of 270 tons to give a steaming radius of four thousand sea miles at 12½ knots speed. The protective deck to have a thickness of .4 inch thick on top and .8 on the sides. The vessel is to have two masts with fighting tops, a steel conning tower, a sharp ram, to be provided with three search-lights and full electric lighting plant. The armament to consist of Hontoria guns, viz.: Two 6-inch, four 4.7-inch, six 57 mm. rapid-fire guns, besides two 37 mm. Hotchkiss revolving guns, four 25 mm. machine-guns and two fieldpieces. There will be two torpedo-tubes and six torpedoes.—Diario de Cadis.
The Cristobal Colon.
This armored cruiser of 6840 tons, built by Ansaldo firm of Genoa, had her trial trips on the 27th and 28th of April. With natural draft, and with 98 to 100 revolutions, she made an average speed of 19.56 knots per hour. During the sixth hour coal consumption trial, during which she made a speed of 18l/2 knots, the consumption of coal was 1.62 pounds per horse-power per hour.—Le Yacht.
Maxim Guns for the Navy.
The latest model of the seven mm. Maxim machine-gun is to be generally introduced into the Spanish Navy. The armored cruiser Carlos V is to be at once supplied with these guns.
[Sweden.]
A New Submarine Boat.
Engineer Nordenfeldt has built a new submarine torpedo-boat, the preliminary trial trips of which both at the surface and at a depth of 30 feet were begun a short time ago. The boat is cigar shape, has a length of 65 feet and a maximum diameter of nearly 12 feet. The motive power is steam, the diving apparatus is automatic. The crew will consist of three men. Trial trips of one hundred and fifty miles will be made between Stockholm and Gothenburg.—Le Yacht.