The three fundamental factors entering into battleship design are armament, protection and speed, and any nation, which in time of war seeks to control the high seas, must have obtained a logical balance between these three factors, in the individual units that constitute that nation's more or less homogeneous battle fleet, if the primary object for that fleet's existence is to be achieved. The battleship, or line-of-battle fleet, is the backbone of any nation's naval strength. It is the trunk of the tree of strength, and the cruisers, scouts, destroyers, dirigibles, airplanes, submarines, auxiliaries, and the remainder of the naval establishment, are merely branches, necessary for its growth, maintenance, and protection, but contributing but a very small part to the actual first-line fighting strength.
The factors—armament, protection, and speed—are the true fundamentals or foundations upon which battleship design must be built, but a discussion of all, or even any one factor alone, will suffice to bring into consideration many other variables upon which theory and successful practice depend. It will show that efficient battleship design does not lie wholly within the province of the sea-going naval officer or of the naval architect, but that it has features which are common to both. This invasion of two fields, in a sense widely separated, makes it necessary for the two classes to collaborate, each giving exhaustive study to the problems of the other, in order that the most efficient unit will be the result.
The strategists of a nation are entrusted with the formation of the plans for use in probable naval campaigns, and in formulating these plans, they must decide upon the number and the military characteristics of the individual units to be employed, in order that such plans may be crowned with ultimate success. These strategists are men, and being men, are merely human. The human brain never has been and never will be entirely infallible. Many grievous mistakes have been made, not alone in policies, but in the design of the tools by which these policies are to be carried out, even after exhaustive study of all the available data bearing upon the subject has been made. War Colleges are the medium through which the game of war is studied. The solution of strategic problems, both by the employment of the active fleet itself, and by the use of constructive ships upon the game board, tends to magnify certain weak points, both in the plans and in the tools with which they are to be carried out, and serves to crystallize certain other disputed questions that become truisms as the game progresses. Thus, as Cyprian Bridge says in substance, "When the military characteristics of a proposed type are finally submitted to the designer proper, the design when finally worked out should embody and express in concrete form the tactical ideas and intentions of the epoch."
The desired military characteristics as submitted to the designer should include the type of ship, the speed, the radius of action, the character of the battery, the degree of protection desired, and the relative importance of the main features of the proposed type. The problem thus presented will admit of many solutions, and there may be many variations in the final design. Thus, to pick the best from among the many legitimate variations, is another problem, upon the solution of which the strategists and the naval architects should combine. This is a condition of affairs in many cases not achieved, due to lack of collaboration, with the result that the final design does not fit exactly into the niche selected for it in the first line of defense.
Nations whose geographical position and national policies arc such that a sufficient and highly efficient navy is a necessity and not a luxury, are at all times either attempting innovations or improving existing designs. The men of science and the naval strategists who are responsible for their respective nations' naval development, are striving at all times to keep just a little in advance of other nations in the field of warship design and their eyes are forever cast over the entire naval architectural world for either proof or disproof of certain questions, questions that may have taken no more concrete form than mere theory. As all warships are designed for use in possible battle, actual war experience furnishes the most positive proof of either the merit or the demerit of certain questions. Action in battle, when all attendant circumstances have been sifted to the bottom, remains the Supreme Court, and its verdict in almost all cases can be accepted as final; not always, to be sure, as witness the adoption of the ram as a method of offense after the Battle of Lissa, and its retention for so many years afterwards. The possibilities of the gun as the primary weapon of offense should have been realized even at that date of its development, and the ram should not have been adopted, for as Naval Constructor R.D. Gatewood has said, "Under modern conditions the gun is the principal weapon of the battleship and concentration of superior gun-fire at the decisive point at the critical time is always the key to victory." The adoption of the ram as a weapon of defense after this battle was a striking illustration of what Rear Admiral Kondo, of the Japanese Navy, warns against, when at the close of the Russo-Japanese War, he said, "One is apt to attach too much importance to experiences gained during the war. No doubt much valuable information was obtained in tactical and strategical matters, though even there, I fear, much has been left unsolved. In naval construction at any rate, I find that many questions which we were anxious to have solved by war experience remain unsolved to the present day."
The same state of affairs of having theories disproved may face the strategists and the naval architects after the present war has passed into history. No doubt, although many salient facts have already been gleaned from the comparatively few naval actions of major importance that have already taken place, many points will remain questions for debate among naval men, and there may be many points adopted that will not stand the acid test of time. Regardless, however, of any mistakes that may have been made by jumping at conclusions from battle testimony, actual war experienceremains the final criterion by which all things naval are either proved or disproved.
Often it has been said that weapons govern tactics. In the present age, under weapons that can be carried by or that can be effectively used against battleships, we can only include the gun and the torpedo. Through all the ages of naval history, both in all fleet actions and in all separate duels between individual ships, since the introduction of the gun upon ships, it and it alone has been the primary weapon of offense, and any discussion of military principles of design should most logically be undertaken by first considering this weapon, in spite of the role played by the submarine with its torpedo in the present war. It is true that the submarine employed in the manner of German ruthlessness, has served a part of its purpose as a commerce destroyer, but its part in the actual engagements that have decided the control of the sea, has been meager and isolated. It has been the gun that has been the decisive factor in every engagement so far, and in battleship design, it is the gun, and its emplacement upon the ship, that should receive the first consideration.
The object of the gun armament of a battleship is to strike offensive blows upon an enemy, in greater number or of greater effect than those received from that enemy. By effective blows is meant blows that will incapacitate or put out of action the individual units of the enemy. By put out of action it is not meant that the opposing ships be actually sunk, although this condition will surely achieve the desired result, but that they will be injured to such an extent that they will be forced out of action, and be unable to deliver their proportionate share of the offensive strength of the fleet as a whole.
There are many ways by which a battleship may be put out of action and be forced to discontinue the struggle. It may be incapacitated by slaughter of the crew; by injury to the armament or the silencing of the guns; by panic among the crew; by the effect of fires; by injury to the steering gear and subsequent loss of maneuvering power; by damage to the propulsive element; and, finally, by the destruction of the buoyancy and stability or in other words, sinking. All of these results of effective blows should be borne in mind during any discussion of the gun, as they are the results sought and which can be achieved by the guns of modern battleships.
In modern land warfare, it has been found to be of advantage to disperse the guns, while retaining- a concentration of effect. In warfare on the sea, it is doubtful whether such a dispersion of the guns is the best course to pursue. If such a principle is adopted it means a greater number of ships with individually fewer guns, if the total number of guns in the fleet is to remain the same. It is also extremely doubtful if such a dispersion of the guns, among a greater number of ships, retains the concentration desired. It is the writer's opinion, that the concentration of fire is weakened by the dispersion of the guns among many units, because in two fleets, with the same total number of guns, that which is composed of the greater number of gun carrying units will form the longer line, and consequently will present the greater target, even though that target be split up into a greater number of component parts. Then again, a fleet composed of a great number of units is tactically weak, inasmuch as it is difficult to maneuver to the best advantage. Looking at the question from the other side for a moment, the same objection holds where the individual concentration is carried to an extreme, as in such a fleet, the units will be of great size, and great size is not conducive to quick tactical movements. Between these two extremes a happy balance must be struck, one that will give both an efficient concentration of armament and efficient tactical qualities.
Concentration of fire, in its broadest sense, means the grouping of as many guns as possible, under the control of the fewest number of fire control officers. Carried to the extreme, it means the installation of as many guns as possible, of the largest caliber, upon each unit of the fleet. Is such a concentration desired? Manifestly riot, for it would result in giving units which though offensively strong, might be defensively weak. "A strong offense is the best defense," has been quoted many times as expressing the law of conflicts. Offensive defense is greatly to be desired, but in achieving it, defensive defense should not be put in eclipse as it would be in a ship carrying a great number of guns, placed promiscuously about its decks. In any design, the three factors, armament, protection, and speed, are functions of one another, closely linked together, and any increase of one will cause a decrease in either or both of the others. Speed, which will be discussed in its proper place later, is both offensive and defensive in its effect, and any great sacrifice of this factor will affect both the offensive and the defensive qualities of a ship. Thus we can see that a ship carrying a very great number of guns will be of great size, clumsy in its movements, present a great target with a multiplicity of parts, both protected and unprotected, and finally such a ship would cost an exorbitant amount for construction. Cost is, after all, one of the limiting factors in the size of ships, and even in these days of prodigious naval expenditures, the element of cost cannot be cast to the four winds of heaven. There is nothing of a technical nature in the art of shipbuilding that limits the size of ships. Ships of sufficient structural strength can be built of undreamed-of size, if it were not for the great cost involved. The prohibitive cost is not merely that of the ship itself, but includes all of the expenditures that become necessary, such as funds for increasing the size of dry docks, lengthening or widening canal locks, dredging channels, increasing repair facilities, and many other items too numerous to mention, that go hand in hand with the upkeep of the vessels. One example of the disadvantage of large vessels is given by the transatlantic liners seized by the United States after the declaration of war with Germany. Many of these fine large vessels were convertible into troop ships, but many of them were really too large to be efficient ships, in that great difficulty was experienced in finding adequate dry dock facilities. For example, one vessel was too large for docking at any place in the United States, and another was so large that there was but one dock she could reach on the Atlantic coast of this country' which was of sufficient size to accommodate her.
In the United States, the size of ships is limited by the length and breadth of the Panama Canal locks, more especially so by the breadth. This is so because it is imperative for this nation to quickly and easily move the main fleet from the Atlantic to the Pacific Coast. If ships were built too large to pass through the canal, this nation could not quickly bring its entire naval establishment to bear upon an enemy. Our ships must pass through the canal, for after the present war is over, there will be no guarantee that our next foe, should there be one, will be in the Atlantic, the permanent station of the fleet, rather than in the Pacific.
The limit in beam and the limit in length for United States ships appear to have been nearly reached in our latest projected battleships and battle-cruisers. If this is so, it would appear that any further development of our ships should be along the lines of improvement of specific parts rather than along increase in size and displacement. Radical changes in ships, and leaps and bounds forward in increasing displacements, tend to produce an heterogeneous fleet, of which the individual units do not synchronize into an harmonious whole, resulting in a clumsy organization that will be tactically weak. Commander Daveluy, of the French Navy, in his "Study of Naval Strategy" says, "All units of the same type ought to have points in common. Progress will not consist in always making something new; it will consist in perfecting the old." It might be well for this nation to bear the above words in mind and to adopt them as a principle, seeking from now on to perfect our ships in the three factors—armament, protection, and speed—on the displacements that have now been reached, rather than to steadily push ahead with increasing sizes of ships, until we reach that state of exorbitant cost, which we will reach if such an advance is continued, when all of the repair, docking facilities, etc., become obsolete and have to be rebuilt.
Assuming that limit of displacements and linear dimensions has very nearly been reached in United States ships, let us now turn to a discussion of the three principal factors of their design.
A. Main Battery
It is safe to state that concentration of numbers of offensive units should only be attempted to the point where any further addition would result in some of the units being placed in positions where they could not be used to the best possible advantage. If such a rule is adopted, we are at once limited to but one arrangement for the main battery of a battleship, namely, the four turret, vertical echelon, counter-line arrangement, as first given to the world in the Michigan class of the United States Navy.
The ideal position for any gun, installed either on land or upon a warship, more especially so upon the latter, is one in which an unlimited arc of train is obtained. This ideal position is manifestly unattainable upon a warship, but it should be approached as closely as possible. The four turret, vertical echelon installation approaches this ideal condition more closely than any other arrangement that has yet been conceived, and should therefore be adopted. This fact has been realized and adopted by almost all nations with the exception of Germany, and from the meager details that have filtered through concerning the latest ships of that nation, it would appear that they too have adopted it. Before the war, the horizontal echelon arrangement, by which turrets are placed on the broadsides, found favor in Germany. It has been stated that the reason for the adoption of this arrangement upon German ships was because England was looked upon as the most probable enemy upon the sea, and the Germans, realizing the inferiority of their fleet in point of numbers as compared to the Grand Fleet of Great Britain, placed broadside turrets upon their ships to guard against the contingency of being engaged on both sides simultaneously.
The horizontal echelon installation combines good end-on fire with great broadside fire. The introduction of a fifth or sixth turret upon the center-line in the vertical echelon arrangement will increase the broadside fire but not the end-on fire, while the introduction of a fifth or sixth turret at the sides of the ship will theoretically increase both end-on and broadside fire.
The objections to the introduction of a fifth or sixth turret, either on the center-line or on the broadside, may be set down as follows: 1. The arcs of train are limited and cannot be as great as those of the four primary turrets, and interferences between the individual arcs will result. 2. Space must be found for the installation of magazines and shell rooms for the extra turrets, causing extra complication in a part of the ship that should be restricted entirely to the housing of the propulsive element. 3. Ventilation and temperature regulation must be provided for these ammunition spaces, to a greater extent than for these placed below the principal turrets, because of their proximity to the sources of heat in the boiler and engine rooms. 4. A fifth or sixth turret would greatly increase the natural length of the ship, a condition which, at the present time, we are endeavoring to avoid, due to the fact that limits in displacements and linear dimensions have very nearly been reached.
The strategists and naval tacticians tell us that column is the only rational battle formation, and that all sea engagements of the future will be fought, or at least commenced, in this formation. By this statement it is not meant that the actual first shots of an engagement will be fired while the ships are in this formation, but that the major part of all actions will take place with the ships in column.
A comparison of the target presented by a ship end-on and broadside-on will prove this a most logical conclusion. Viewed end-on a ship presents a small target perpendicular to the line of fire but a relatively large target parallel to the line of fire. Viewed broadside-on, a ship presents just the reverse of the above—a large target perpendicular to the fire and a relatively small target parallel to the fire. No one misses in deflection, especially when the target does not change bearing or changes very slowly, as it would in a ship end-on. It is errors in range that cause 90% of the misses; consequently, the fire against a ship end-on is much more easily controlled than against a ship broadside-on. Again, the large target perpendicular to the line of fire presented by a ship broadside-on, is the one upon which in almost every case the greatest amount of protection has been placed and is consequently the one best fitted to withstand or minimize the effect of the enemy's projectiles. Again, tactical conditions which facilitate frequent hits, the fundamental object of any action, are constant range and relative bearing, which in other words, means that ships must steer parallel courses, either curved or straight.
Thus, from a defensive point of view, we see that column is the most logical formation for battle. From an offensive point of view we may reach the same conclusion, for with center-line turrets, when an enemy bears anywhere in the neighborhood of the beam, the greatest number of guns can be brought to bear. From this point of view, a fifth or sixth turret upon the centerline might seem justified, but axial or end-on fire, however, must not be lost sight of entirely, as there may be many times during the tactical evolutions of battle when end-on fire will predominate. In these instances the fifth or sixth turret on the center-line will be valueless, as their arcs of train will be so greatly restricted that they cannot be brought to bear upon the enemy.
It would seem that the disadvantages, as enumerated above, far outweigh the advantages of a fifth or sixth turret, and that their installation in any case is hardly justified. With the four turret installation, with two turrets in each of the principal gun stations, number two and number three must of necessity fire over turrets number one and number four, to retain the maximum of end-on fire. It would be possible, of course, to install a third turret in each of the gun positions, making' six turrets in all, the third turret in each position firing over the other two, but this solution for increasing the gunfire of a ship is not considered logical, as it is open to the objection of increasing the length and consequently the displacement of the ship. Again, the installation of a third turret in each of the gun positions firing over the other two would require a great height of armored barbette, which would materially raise the center of gravity of the ship, thus affecting the stability.
Having followed through a course of reasoning that would tend to show the four turret, vertical echelon installation as the best arrangement for the main battery of a modern battleship, the next questions that present themselves are the caliber of the guns and the number that should be installed in each turret. These two questions are more or less closely connected, and in the discussion to follow they will be considered more or less closely together.
First, as long as the primary object of the main battery is to inflict the greatest possible damage to an enemy, it would seem that the best gun for a battleship is the heaviest or largest gun that can be carried. Admiral Sir Reginald Custance, R.N., has said that "the best armed ship is that which carries the largest numbers of the smallest guns that will do the work." This statement is merely a statement of the obvious, and in considering it, it resolves itself into the question whether or not the smallest guns that will do the work are not the largest guns that can be carried.
Heavy guns have many advantages. 1. With large calibers the muzzle velocity can be reduced, thus diminishing the erosion of the bore and increasing the life of the gun, while maintaining ample penetrating power and superior maintenance of striking energy at long ranges. 2. The larger the caliber, the flatter will be the trajectory of the projectile, and the greater will be the accuracy of fire. 3. The larger the caliber, the heavier will be the projectile. As the bursting charge carried by a projectile is a certain percentage of its weight, it follows that the larger the projectile, the greater will be the bursting charge, with subsequent greater shell effect on striking the target. 4. With large guns, if a certain effect of fire is selected as a standard. the number of guns that must be mounted upon a ship in order to maintain this standard, can be reduced. 5. Large guns have a greater range than small guns, with the result that a fleet mounting the heavier guns can outrange a fleet having smaller guns.
There is a question whether the fifth advantage given above is really an advantage in point of view of fact. In speaking of heavy guns, the 12-inch is the smallest gun that can be considered in that category, as it is the smallest weapon that has been installed as the main battery for battleships of any first-class naval power with the exception of Germany. The Germans for many years installed the 11-inch as the primary weapon, but even they, before this present war commenced, had abandoned this gun for a heavier caliber, and it is not conceivable that any nation, after sifting the results of the naval actions of the present conflict, would retrogress to any caliber less than 12-inch, even if it returned that far. As long as this is the case, it is a question if the heavier the gun the greater will be the range of future engagements as the 12-inch gun is of ample penetrating power even at extreme ranges, to penetrate the armor as installed on modern battleships.
Some authorities have said that the effect of projectiles is dependent upon the point struck; that small shells on the right spot are more effective than large shells on the wrong spot, and that it is a mistake to compare gun power by the weight of the broadside. They claim that a great volume of fire against a ship is more effective in putting it out of action than a smaller volume of fire, even though the weights of the two volumes be the same. They point to the fact that the turning point of the Battle of Round Island, August 10, 1904, was when fragments of shell entered the conning tower of the Russian flagship.
Among the advocates of a great volume of fire, which in reality means a proportionately heavier secondary battery combined with the heavy guns, was the late Sir William White. In a paper written for the American Society of Naval Architects and Marine Engineers, this eminent naval architect advocated the use of a powerful secondary battery of quick firing guns. He argued that such a battery would be of inestimable value in a naval action, because he believed that there would be many times during the course of an action, when the range would be such that the addition of a battery of guns that could fire so much more quickly than the main battery would be of tremendous advantage. Personally the writer is a firm believer in secondary batteries for first line battleships. He believes that quick firing guns should be installed as secondary batteries but that such batteries should be truly secondary in their nature. He believes that the installation of quick firing guns should not be carried beyond the point where they interfere with the installation of the main battery. In other words, he believes that first thought should be given to the heavy guns and second to the smaller guns. Decide first what heavy guns are to be installed on a certain design, then fit in the secondary battery, keeping in mind the fact that a secondary battery must be installed when deciding upon the heavy guns. With this end in view, he will continue with the discussion of the heavy guns, leaving the secondary battery to follow in order.
It naturally follows that blows from heavy guns must have a greater effect than blows from lighter guns, and after all it is the effect of the blows that counts. The primary object of the armament is to put the enemy out of action, and if this can be done more effectively and more quickly by heavy guns, why not install as heavy a gun as can be carried, especially as the heavier the gun the greater should be the accuracy at long ranges? On the displacements that have now been reached, say up to 40,000 tons, there is no reason why the main battery should ever be less than 14-inch or even 16-inch. It would seem that the only limit to the caliber would be that imposed by the installation of the guns within the turrets on the ship.
If the above is the case, the decision of what caliber should be installed depends somewhat upon the construction of the turrets. Is it best to install two, or is it best to install three or even more guns, in a turret? For many years the 2-gun turret found popular favor in the navies of the world. Then the Italians took up the question of mounting three guns in each turret. In the first of these turrets the three guns were individually operated, causing a multiplicity of parts within the turret. This never found favor and it was not until the first 3-gun turret was developed in this country that the world really took serious notice of this installation. The most important advantages of the 3-gun over the 2-gun turret are the fact that if heavy guns are installed only in the principal gun stations, the number of guns can be increased without a reduction in efficiency of the individual guns, and the fact that the three guns can be mounted and be as well protected as two guns with only a slight increase in the armor weight.
In the first 3-gun turrets developed in this country the three guns were all mounted in one sleeve, that is, all the guns were elevated and depressed together. This installation had the advantage of reducing the size and weight of the hood and the barbette over a turret in which the guns were independently controlled, and also in the simplicity resulting from a reduction in the number of necessary power units within the turret. It had the following disadvantages: 1. With one control of all guns, if anything happened to that control, all three guns were put out of action. 2. It was impossible to separate the turret into parts; that is, the guns could not be isolated from one another. 3. There was an exaggeration of danger from a hang or miss fire.
For obvious reasons the details of the construction of the latest 3-gun turrets of the United States Navy cannot be discussed. Let it suffice to say that the turrets of the Mississippi and later ships are great improvements over the first 3-gun turrets as installed on the Oklahoma and Nevada. With such the case, it can be safely stated that the 3-gun turret has been proved in service and has come to stay. It has arrived at the stage where it is an actuality and not a theory.
And now we reach the point where we may ask: Is it feasible or logical to install more than three guns in a turret? Only two nations, France and Russia, have attempted this installation. In fact it may be said that France is the pioneer in this field, as a study of warship development will show that Russian naval progress, with but little exception, has been parrot-like copying of points from other navies. France has attempted the 4-gun turret, but in so doing has not attempted to install any such heavy guns as 14-inch or 16-inch caliber. It would seem that by going to the 4-gun turret France has attempted to maintain the same striking energy of fire from a ship without going to extreme size of gun. The 4-gun turret is, of course, open to the same objections that were advanced against the 3-gun, when that installation was first proposed, but in this case it would seem that the objections would more rigidly apply. It would seem that the 4-gun turret will never find popular favor as the proper installation for the heavy guns. Of course, such a prophecy may prove as erroneous as the prophecies of failure that were made when the 3-gun turret installation was first proposed. It would be entirely feasible to build a ship with four 4-gun turrets mounting guns of the largest caliber, but such a ship could not be built within the displacements and the linear dimensions that have now been reached, without making enormous sacrifice in both protection and speed. Such sacrifice would destroy the proper balance between the three factors, and the resulting ship would not be a logical solution of the problem.
From what has been said, at the present time the question is whether a ship should carry four 2-gun turrets with 16-inch guns, or whether it should carry four 3-gun turrets with 14-inch guns. It has been figured by certain authorities that the weight of a 2-gun 16-inch turret with all appurtenances is sensibly equal to the weight of a 3-gun 14-inch turret. If the weights of the installations are equal, both can be installed on the same ship without disturbing the other two factors of the design. Which is the better installation and which do we wish to install? Let us consider for an instant the comparative weights of the broadsides from the two installations. A 16-inch projectile weighs approximately 2050 pounds and a 14-inch projectile, 1375 pounds. With these weights, from eight 16-inch guns we could have a broadside weighing 16,400 pounds, and from the twelve 14-inch a broadside weighing 16,500 pounds. Again also an equality, and once again we may ask, which installation do we wish to install?
It appears to the writer that one way of arriving at a choice between the two is by advancing the argument of the advocates of a secondary battery, namely, the volume of fire. The weights of the two broadsides being the same, that from the 16-inch will be the more concentrated. It would seem that here the virtues of the argument of volume of fire would apply to the 14-inch installation, as it is considered that in the 16-inch installation the concentration is carried beyond the logical limit. A miss with one 16-inch shell means a loss of striking power of 12.5 per cent, while a miss with one 14-inch shell means a loss of striking power of only 8.3 per cent. Of course, with installations of 12 guns and 8 guns respectively, there is 50 per cent more chance of missing with the former than with the latter, but there is also 50 per cent more chance of hitting. With such the case, it would seem that the advantage lies with four 3-gun, 14-inch installation rather than with the 16-inch, and it is not considered that the increase of accuracy of the latter is sufficient to offset it. The 14-inch is almost as accurate a weapon as the 16-inch at the extreme ranges at which future battles are likely to take place, and as such, any advantage that the 16-inch may have in increased accuracy is nullified as battle ranges have now reached almost the limit of visibility even from elevated fire control towers. It may happen that in some future naval engagements the fire of opposing fleets may be controlled and directed by air craft, the ships themselves being out of sight of one another. If such should be the case, the 16-inch will prove to be the best weapon to install, but until that time we may safely say that at modern battle ranges the 14-inch is every bit the equal of the 16-inch as a battleship gun, provided that the guns are installed in the ratio of 12 to 8.
Again, let us consider the effects of projectiles striking a ship. The effects of shell fire are two in number, 1. Shell effect. This is the demolition of the unprotected structures of a ship, caused by the charge of high explosive carried by the projectile. 2. Penetrating effect. This is the effect of armor penetration and is the effect that is most likely to reach the vitals of the ship. With a battery of twelve 14-inch guns both of these effects should be much greater than with eight 16-inch guns. With the latter, the local effect will or may be greater, but by the doctrine of probabilities, too much faith should not be placed on any one method of putting a ship out of action, and as the 14-inch can penetrate armor at modern battle ranges, it would appear once again, that 14-inch guns in four 3-gun turrets would prove superior in accomplishing the object of the main battery, namely, to put the enemy out of action in the shortest possible time.
From all the arguments set down above, it would appear that on present displacements and linear dimensions, which are not likely to be exceeded very much in the near future, the best battery that can be installed for the main battery of battleships, is the four-gun 14-inch turret installation.
Before leaving the subject of the main battery, it might be pertinent to remark that a four 3-gun 16-inch turret installation would be as much superior to a four 2-gun 16-inch turret installation, as is the 3-gun 14-inch turret to the 2-gun 14-inch turret. However, it is beyond the realm of the possible to install such a battery on displacements of less than 40,000 tons without destroying that balance between the factors that we should be endeavoring- at all times to maintain.
B. Secondary Battery
What is the primary object of the secondary battery of a modern battleship? Is the primary object one of offense, or is it one of defense? There are many authorities—the same who argue for an extraordinarily powerful secondary battery, a battery which if installed on a modern battleship would necessitate a material weakness of the main battery—who claim that this battery is, or should be, for purposes of offense. A little thought on the subject, however, should serve to show that this battery should be purely defensive in its character, a species of offensive defense, if it is desired to call it such. Modern battle ranges are so great that the part to be played by even the heaviest of secondary guns will be small, and even then, they should have but a very small effect upon the final outcome of the action. The value of secondary batteries was amply proved during the Russo-Japanese War by the Japanese fleet at Tsushima—Captain Semenoff of the Russian Navy, in his book describing that action, bears ample witness to the overwhelming effect of the volume of fire from the enemy—but it must be remembered that Tsushima was before the advent of the Dreadnought, when the batteries of battleships were of mixed calibers. First line ships of the present day are essentially single caliber ships, and due to the increase in power of the main battery, ranges have increased so much that the secondary battery guns cease to be a vital element in the strictly offensive power of the ship.
If the secondary battery is not offensive in its character, in considering it and the weight to be allotted to it in the design, we should start with the idea that these guns are strictly for defense. If we approach the question in this manner, how much thought should be given to these guns in connection with the main battery? In deciding upon the main battery, the existence of the secondary battery should always be kept in mind, for if it is forgotten grave errors may ensue. If we go ahead blindly in a certain design, deciding upon the main battery, forgetting the secondary battery. we may find that when we finish on the displacement allowed, an efficient secondary battery cannot be installed. Such a situation arose when the Michigan class of the United States Navy was designed. Four twin 12-inch turrets were installed on a displacement of 16,000 tons, with the result that the secondary battery could only be made 3-inch. These ships were in reality not faulty in design. They were a transition state between the older battleship and the dreadnought type, it being the intention to obtain as much heavy gun power as possible from the money appropriated by Congress. These ships were in one way an experiment, and a very valuable experiment, in that they proved the practicability and the efficiency of the vertical echelon, center-line arrangement of the turrets. These ships, however, may serve to show that everything desirable for a warship cannot be secured on a limited displacement, but on displacements of not over 40,000 tons, which we are now discussing, it is entirely feasible to install an efficient secondary battery, in connection with a most efficient main battery.
The primary object of the secondary battery should be that of protection or defense against torpedo and air craft attack. The submarine in the present war has proved to be a valuable asset as a commerce destroyer, if used in the ruthless fashion as it is by the Germans, but as yet it has played no major part in fleet actions. The main fleet of a nation will always be protected against submarine attack by a screen of destroyers, the submarine's most deadly foe, and it is for defense against these same destroyers of the enemy that the secondary battery should be installed.
The destroyers of the present day, with displacements of around 1000 tons, are in a great measure self-supporting, much more so than the submarine, enabling them to accompany the main fleet, and to hold their designed speed in almost any kind of weather likely to be encountered. If they can accompany the fleet, they are a constant menace to the safety of an opposing fleet. Owing to the maximum range of the automobile torpedo, attacks by this class of vessel must of necessity be made under cover of darkness, for the boats must be able to creep up to within the effective range of their torpedoes undiscovered by the enemy, if the attack is to be a success. Modern battleships must be armed with guns to combat these possible destroyer and submarine attacks, and these guns are the secondary battery. If their purpose is to l)c accomplished, these guns must be quick firers, and if we
apply the same arguments that lead to increase of caliber of the main battery, we will install the largest caliber possible for the secondary battery. If the guns must be quick firers, the largest caliber that can be employed is either the 5- or 6-inch. This limit is set by the weight of the projectiles for these guns. They are the largest that can be conveniently man-handled, as they must be to obtain rapidity of fire, the cardinal virtue of the secondary battery.
If the secondary battery is not of major importance in deciding the outcome of a naval engagement, it will nevertheless play its part. To do this, however, it should be efficiently placed upon the ship, and should be well protected. This is necessary because of the fact that, in any fleet action, the opposing ships are bound to receive severe punishment from the pounding of the heavy modern projectiles, and if the secondary battery is not protected in such a manner that at least some of the guns are available for use after the main action, the results may be disastrous. The individual vessels of the vanquished fleet will endeavor to escape after an action, and unless some of the secondary battery guns remain fit for use, these wounded vessels will fall easy prey to the destroyers of the victor, which remaining out of range during the main action, will pursue the beaten ships on the chance of launching an effective torpedo attack. This was exemplified at the Battle of Tsushima. The Russian ships, after being put out of action by the Japanese, were entirely at the mercy of the horde of destroyers that appeared as soon as the main battle was over. Due to the faulty protection given the secondary battery guns of the Russian ships, these vessels found themselves with no effective defense against the Japanese boats. The Japanese were able to advance to within effective torpedo range, and the Russians with demolished armaments and in many cases demolished stability, fell an easy prey to their diminutive opponents.
Another use for the secondary battery is in defense against attack from the air. Anti-aircraft guns, like the secondary battery discussed above, must be quick firers, and in consequence, they must be small in caliber. As yet, aircraft have not played any part as true offensive weapons in fleet action. Their role has been more of a scouting and fire control nature, and it would appear that this is the principal part that they will ever play. The best defense against aircraft, both in land warfare and warfare upon the sea, has been found to be other aircraft, and with this the case, the anti-aircraft guns of a modern battleship need be but small in caliber and few in number.
C. Torpedo Armament
By almost common consent, after the experience of the United States and of Spain in the War of 1898, naval authorities agree that the only form of torpedo discharging apparatus that should be installed on large vessels is the underwater or submerged tube. All authorities agree that this is the only type of tube to install, but they do not agree that the torpedo is a rational weapon for a battleship to carry. Some designers claim that due to the inaccuracy of fire of torpedoes in general, and to the inaccuracy of all curved fire devices in particular, this weapon should not be installed on battleships. They also claim that the space and weight necessary for the installation of torpedo rooms and torpedo discharging devices can be more advantageously employed to increase the effective fighting qualities of a particular ship. These claims would seem to rest upon solid foundation, as at best the present-day torpedo is an inaccurate weapon. It is also a short range weapon when its effective range is compared to the range at which modern sea battles are likely to be fought, and as such, it is not an effective or efficient weapon for a battleship to carry. However, the speed, size, accuracy and effective range of the torpedo will most probably increase in the future as they have in the past, and if they should increase to such an extent that this weapon can be considered effective at future battle ranges, it should most assuredly be installed as part of the main offensive armament of the ships of the future. For the present, and in the immediate future, however, it would seem that the employment of the space and weight necessary for the installation of a torpedo armament is not justified, if the battleship is to be the most effective ship that can be obtained, keeping in mind the true functions of the class.
The fundamental object for the existence of battleships is, as has been said before, to obtain the control of the sea. This is obtained by bottling up the ships of the enemy so that his ships are of no use to him, or by quickly and effectively putting his ships out of action. The armament is installed for the purpose of achieving these results upon which the control of the sea depends, while the passive defensive protection is installed to insure the least possible damage to the ship while this objective is being achieved. Protection is then a method of insurance which tends to decrease any disastrous results to a minimum. It may be compared, in a measure, to the fire department of a large city. This department is not provided to prevent fires, as that is obviously impossible, but to minimize as much as possible the destruction of property, thus reducing the effects of a natural agency, which in the natural course of events, cannot be prevented, however efficient the precautions. And so it is with warships in general. If there were no possibility of future battles upon the sea, there would be absolutely no need of fighting ships, but as long as the probability of future sea actions does exist, fighting ships will be constructed as an insurance against the effects of the naval might of an opposing power, and being constructed, they should be designed from the best data available, keeping in mind all of the conditions that must be met.
The protection of a modern battleship naturally divides itself into protection against the three weapons that can be used to put such a ship out of action, namely: protection against gun-fire, protection against under-water attack, and protection against aerial attack. It is in this order that the question of protection will lie discussed.
A. Protection Against Gun-Fire
The protection of a battleship against gun-fire consists not only in fitting armor to the different portions of the ship to protect its vitals, but also in reducing the target presented to the fire of the enemy. The vertical target presented by a modern battleship viewed broadside-on, must necessarily be great, due to great displacements, but every energy of the designer should be brought to bear to reduce this expanse of target to a minimum. This can be accomplished by reducing the freeboard, superstructures, and the great number of unprotected parts. The freeboard of a ship depends entirely upon the condition of speed and seaworthiness which must be met. The stability and stiffness of a ship and hence the steadiness of the gun platform, depend directly upon the freeboard. The all big gun ship presents serious problems in the question of metacentric height and range of stability. A great metacentric height will mean a stiff ship, quick rolling and thus a bad gun platform. On the other hand, a ship with a small metacentric height, which may be perfectly stable in an undamaged condition, may be unsafe when damaged incident to an action. Between these two extremes we must choose the proper metacentric height, and as this element or measure is affected by the freeboard, we can see that not much modification can be made by the designer on this element of the design. Again a ship must be given a freeboard sufficient to allow it to maintain its speed in a seaway, thus further restricting the designer.
On the other hand, superstructures have no direct bearing upon either the fighting or seagoing qualities of a ship, and consequently in modern ships the abandonment of these towering useless structures was absolutely justified. Superstructures, if fitted at all, should consist merely of skids for the proper stowage of boats in time of peace, and should be made portable in order that they may be thrown over the side when an action is imminent.
All unprotected structures, such as funnels, masts, deckhouses, bridges, ventilating trunks, boat-handling gear, skids, etc., should be reduced both in number and extent as much as possible. A great advance has been made in this direction in the latest United States ships, in which the arrangements of boilers is such that but one smoke pipe is installed. This was made possible by the introduction of oil fuel. Deckhouses should be abandoned, or if fitted should be so constructed that they can be got rid of when clearing ship for action. Ventilators, especially of the cowl type, should be made portable so that they can be removed when going into an action. Bridges should be portable, and stations for flag signalling should be supplied where the signalmen will be in more or less protected positions. One method of protecting the signalmen is by installing the flag signalling station in the conning tower, as suggested by Professor William Hovgaard (formerly Commander, Royal Danish Navy) in his paper on "Conning Towers," published in Jane's "Fighting Ships" for 1908.
Large masts of whatever character, while necessary for efficient fire control, constitute a grave menace to a ship in action, and where all the duties of two masts can be performed by one, only one should be installed. Masts, especially of the cage or basket type, as fitted in the United States Navy, add greatly to the target presented at long ranges, and although ingeniously constructed to withstand gun-fire, they will be exposed to the action of high explosive shell, and will cause a multiplicity of fragments and splinters and may ultimately be brought down, thus hampering the handling of the ship and the proper working of the offensive parts.
Boats carried by a battleship in action should be few in number, constructed of metal, and if possible, should be housed in protected spaces, preferably behind armor. Wooden decks should be reduced to a minimum and should never be fitted on superstructures or bridges, the experiences of the Russo-Japanese War having shown that wood will ignite from shell explosions, even when laid upon all steel decks.
After everything possible has been done to reduce the target presented by the design in hand, the next question that presents itself is. How shall the ship be protected against the blows that are bound to fall upon it from the gun-fire of an enemy?
Some authorities claim that no armor should be fitted to a ship, that the weight necessary for the installation of the armor can be more advantageously used to increase the armament and the speed. There is no doubt that the armament of ships suffered by the introduction of armor, but it is still an open question, whether or not the protection gained did not greatly outbalance the loss in offensive power, as far as the efficiency of the whole was concerned. As all first line ships of the present day have armor protection, we may safely assume that the naval strategists of all nations agree that this protection should be fitted, if an efficient ship is to be obtained.
In any discussion of armor we first run into the question of the decisive range. Just what is the decisive range? This may be defined as that range at which the offensive units are capable of defeating the defensive units. In other words, it is the greatest range at which the guns of a ship can penetrate the armor of an opposing ship. This would seem to be more or less of a constant quantity but in reality is quite variable. It is a variable dependent upon the weather, the state of the sea, and many other conditions too numerous to mention, so that no range can be absolutely set as the decisive range for any size of guns or any thickness of armor. In other words, a first-line ship of war should be prepared for action at any range, as an enemy with superior speed may be able to choose the range that will be the most advantageous to him. Admiral Farragut at Mobile Bay showed that unarmored ships must close with ships that are armored, consequently an enemy if more lightly armored will endeavor to close if a decisive action is desired.
Thus we see that if a ship must be prepared for action at any range, it would seem only logical to so protect the ship that the blows of the enemy will be minimized or localized in effect, and this protection can only be gained by the installation of armor upon the hull structure of the ship.
The opponents of armor raise the question of the accuracy of fire. That is, they contend that as the range increases, the accuracy of fire will decrease, and consequently the vital hits, the effect of which must be minimized by the armor, become fewer and fewer in number. The statistics upon the accuracy of fire in action are meager and the few following are set down for what they may be worth. At the Battle of Lissa, the Italians made 412 hits, which was 22% of the total number of shots fired. At the Battle of Point Angamos, the Chileans made 28% hits. These two actions were at comparatively short ranges and their relation to what might be expected in present-day naval actions is almost nil. Continuing, at the Battle of the Yalu, the Chinese made but 5% hits, while at Santiago, the United States Fleet made the grand total of 3.2% hits. Again during the Russo-Japanese War, at the actions of Chemulpo, Ulsan, and the Battle of Round Island on August 10, 1904, the Japanese hits averaged 6.8% to the Russian 9%. Of the naval actions of the present war, the writer has been unable to find any statistics on the number of hits, but it is not considered too radical to predict that the hits on either side would not number more than 10% of the number of shots fired.
We can only predict for the future by what has happened in the past, and from the results of experiments made in times of peace. It is well known that improvements in guns, sights, methods of fire control, etc., have increased the accuracy of fire at target practice even at extreme ranges, but target practice, even though approaching the conditions of battle, is not battle, and the accuracy is bound to be less in the heat and stress of an action. It is one thing to fire at a defenseless target and another to fire at an enemy that is firing back. Considering protection then only from the point of view of accuracy of fire, it would appear that the weight of the armor could be more advantageously used to increase the number of guns, as an increase in the number of guns means a corresponding increase in the probability of hitting, and consequently a greater chance of putting an enemy out of action. On the other hand, even with a low accuracy of fire, some shots of the enemy will take effect, and one shot in a vital spot would entirely vitiate the advantage gained by the increased number of guns obtained by the sacrifice of the armor. A shot that might be fatal on an unarmored ship, might not be fatal on one that is armored, as the armor might have the effect of minimizing or localizing the effect of the projectile. It would seem, looking at the question from this angle, that armor should be fitted to any fighting machine, as any ship must be capable of taking as well as giving punishment, and a ship upon which no armor has been installed is totally incapable of withstanding the punishment of exploding shells.
Again, the opponents of armor have advanced the argument that due again to the inaccuracy of fire, the risk of the destruction of the buoyancy and the stability has been over-emphasized, as the chance of hitting the water-line of a vessel is comparatively small. They point to the fact that the armored Huascar at Point Angamos and the Spanish ships at Santiago were defeated without compromising their floating power. They claim that this immunity was due to not being hit near the water line and not to the presence of the armor. In considering this question it can be easily seen that the two cases mentioned are but isolated incidents, and that no mention is made of the many instances in actions of the past, where the buoyancy and the stability have been destroyed, thus most effectively putting the ships out of action. It is to protect this buoyancy and stability of a ship that the armor is fitted and its presence will surely tend to lessen any disastrous effects.
Another question raised by the opponents of armor is the question of installing armor for the protection of the guns. One example cited is that of the Russian Orel in the battle of Tsushima, on which ship but 6% of the total number of hits received were on the gun positions. In spite of the fact that no armor installed for the protection of the guns was penetrated, eight of the twelve 6-inch and two of the four 12-inch were silenced. Naturally the question arises. If these guns were silenced without penetrating; the armor installed for their protection, of what use was the armor? As has been said before and is repeated here, armor is merely an insurance, and in the case mentioned who can say, as long as the armor was not penetrated, just what would have happened if no armor had been fitted? No one knows just how many hits were made upon the gun stations that did not put any gun out of action. All we know is that the armor was not penetrated, so that it must have successfully performed some of its functions, as every hit upon a gun station did not put a gun out of commission, as it most assuredly would have done if no armor had been fitted. Again we know that if no armor had been fitted, all of those shots that hit upon gun stations and were stopped by the armor would have entered the ship unhindered, and would have caused much more damage to the ship structure and much greater loss of life than that which actually occurred. As Admiral C.C.P. FitzGerald, R.N., has said, "Guns mounted behind armor and a protected water-line should surely prolong the life of a ship in an action." By prolonging the life, he meant not only the preservation of the buoyancy and the stability, but the preservation of the effective offensive as well.
Last but not least among the many arguments for armor is the moral effect upon the personnel. It is an ineradicable trait of nature for a human being to fight much more courageously if he knows that he has a good defense, even though it be not impregnable. The presence of armor gives just this necessary feeling of security to the crew, and it should be fitted for this reason alone if for no other, as we must remember that loss of morale is one of the many ways in which a ship may be put out of action.
Having presented some of the many arguments for and against the installation of armor, let us now consider how it can be best distributed in the hull of the ship, to be most efficient in combating the effects of gun-fire. One of the primary objects of hull armor is to preserve the maneuvering power of the ship. The most vital parts of a ship in action are the conning tower and the boiler and engine rooms. While the conning tower is the brain of the ship, the engine and boiler rooms are the heart, and this, in a ship as well as in a human being, must be protected, as penetration in this region will as surely kill the ship as it will a man.
All the experience gained from the Russo-Japanese War and from numerous armor tests, notably those conducted by the French on the Jena, leads to the conclusion that armor of heavy and moderate thickness should have the greatest possible extension over the sides and length of the ship, and that no armor less than four inches in thickness should be installed, except for armored decks and possibly for under-water armor below the main belt. It is a question in the writer's mind if it would not be logical to install armor of moderate thickness, extending from the lower edge of the main belt down to the turn of the bilge, as even in his very brief experience, he has seen the result of one common 12-inch target practice shell which penetrated two thicknesses of 15 pound plate, set two feet apart, at a distance of 18 feet below water.
The main belt should, of course, be thickest in the region of the water line, and should gradually be reduced towards the ends of the ship and up to the main deck. The true vitals of the ship, or the heart as mentioned above, lie in that portion of the ship included between the limits of the two main gun stations, and it is to this part of the ship that the greater portion of the protective armor should be applied.
There are other important parts of the ship however, that must not be forgotten when the distribution of the armor is considered. The turrets, the barbettes, and the conning tower should all be well armored. The secondary battery, installed on a deck not lower than the main, between the two principal gun stations, should be well protected, the individual guns being isolated from one another by splinter and gas tight bulkheads. The uptakes, above the protective deck, and the smoke pipes should be armored. If it is found impossible to armor the entire height of the smoke pipes, they should be protected to as great a height as possible.
Finally, for protection against gun-fire, there should be fitted at least two armored decks. As has been brought out in the first part of this paper, there may be many times in an action when the ships will l)e engaged end-on, and in this position the decks will be exposed to the plunging fire of the enemy, especially if the action is at any great range. Again when engaged broadside on, even a moderate roll will expose the decks to plunging fire, and it is to minimize the effects of this fire that the two armored decks should be fitted.
B. Protection Against Submarine Attack
Protection against submarine or under-water attack is gained by minute water-tight subdivision and by the use of torpedo nets. The torpedo net has never found favor in the United States Navy even though it may be said to possess many advantages. The advantages, however, have not been considered by the United States authorities as compensating for the disadvantages, and the torpedo net has therefore never been adopted. These nets may prove to be of extreme value to an anchored ship, when exposed to under-water attack, as was exemplified by the use to which they were put in the protection of the Russian battleship Sebastopol at Port Arthur, when it is estimated that over 150 torpedoes were fired at the vessel. The ship was struck directly once, and damaged several times by explosions in the nets, yet at the end of the siege, she still remained afloat. Nets fitted to a ship which is underway, will greatly increase the resistance to propulsion, and consequently will reduce the speed. This reduction in speed of a fleet will be great enough to wipe out any superiority or advantage that the fleet may have over an enemy, thus materially decreasing the tactical efficiency of the fleet as a whole. For this reason, nets, even if fitted to modern battleships, would not be used in fleet actions, and would only be employed by ships at anchor, when it is not necessary to consider the speed element.
The water-tight subdivision of a battleship, below the water line and even above it, constitutes a vital element in the efficient protection of the ship, and must receive very careful consideration from the designer. The discussion that can be set down here can be only brief in form, but an attempt will be made to outline in general the main essential features, without delving too much into the details.
The subdivision of a battleship serves two cardinal purposes first, as a minute water-tight subdivision for protective purposes, and second, as a means of best utilizing the space within the ship.
The question of the subdivision of a ship falls naturally into three distinct parts: first, that portion of the ship below the highest protective deck; second, that part of the ship in the region of the water-line; and third, the upper part of the ship. From a point of view of protection, the different parts of the ship as set down above are in their relative order of importance.
The lower part of the ship, from the outer skin to the height of the upper protective deck, is the most vital part of the whole, as regards water-tight subdivision, as it is this part of the ship that is exposed to the dangers from gun-fire, from grounding and collision, and from submarine mine and torpedo attack. On battleships as constructed at the present time, the ship's side below the armor shelf is very pregnable. Owing to the lack of strength of the outer skin, this part of the ship should be divided into a great number of minute water-tight compartments. The outer shell should be separated from the interior of the ship, where the ship's vitals are contained, by the inner bottom. This doubling of the bottom should be carried as far as possible towards the ends of the ship, and in every case should extend to at least beyond the limits of the two gun stations. The space between these two shells should be minutely subdivided into small pockets, and access to these spaces should be had only through manholes.
From a consideration of the effects of flooding compartments upon the stability and heel of a ship, these compartments of the double bottom, and in fact all compartments of a ship, should be great in transverse dimension and comparatively short in the fore and aft direction. This statement implies that the vertical keel should always be non-water-tight, and in general this should be the case in all ships. However, if the space included between the two shells of the ship is very minutely subdivided, as it always should be, it will make comparatively small difference whether the statement made above is strictly adhered to or not. From a military point of view, it is essential that a ship have but small heel for the efficient working of the guns, and a good rule given by Professor Hovgaard in his lecture course states that if the vertical keel is made water-tight, the flooding of two compartments on one side of a ship should not cause a heel of greater than one degree.
Inside of the inner shell, running parallel to the center-line of the ship, there should be a series of bulkheads spaced a few feet apart, the actual number being that determined after experiments as necessary for the efficient protection of the ship. In most cases of collision, both the inner and outer shell will be destroyed, but the damage will be more or less local in its effect, and the presence of these wing bulkheads will serve to minimize any disastrous effects. In the case of an explosion against the outer shell, a much greater area of the skin will be affected, and the damage probably extend much farther toward the interior of the ship. The inner shell and some of the wing bulkheads will most probably be destroyed in the region of the explosion, but the probability is that one, if not more, of these wing bulkheads will remain intact, thus insuring the safety of the ship.
It has been the practice in the past to make one of these longitudinal bulkheads an armored bulkhead. This has been placed about fifteen to eighteen feet from the side of the ship. In the ships of a few years ago it was called the side coal bunker bulkhead in ships using coal as fuel, and it had the disadvantage that doors had to be cut in it to facilitate the handling of the coal, when in reality to be most efficient it should be left intact from end to end. This disadvantage is obviated in ships burning oil exclusively.
The question of whether one of the wing or explosion bulkheads should be armored, or whether this armor can be more efficiently placed elsewhere is a mooted one. Under-water armor has invariably been applied to this bulkhead in ships of a few years back, but in recent years it has been stated that this armor would he more efficient if applied directly to the outer skin of the ship. A careful reading of Professor Hovgaard's article, "Protection of Battleships against Submarine Attack," published in the 1909 edition of Jane's "Fighting Ships," will show that at least one authority on warship design believes that under-water armor would be more efficient if placed directly upon the skin of the ship. Again, as has been stated above, shells have been known to pierce steel plates of the thickness of the skins of battleships, at a considerable distance below water. This could not happen if armor were placed directly upon the skin of the ship. If this were done the chance of high explosive shell entering the vitals of the ship below the main armor belt, with the subsequent possible disastrous results of the explosion, would be entirely eliminated. Armor, applied directly to the skin of the ship, from the lower edge of the main armor belt down to the turn of the bilge, would possibly be of greater value to a modern battleship using oil as fuel than to a coal-burning ship, as by the introduction of oil the protection afforded by the coal in the side bunkers is entirely sacrificed.
We have considered so far only the longitudinal water-tight subdivision of the lower part of the ship. Let us now turn to the transverse subdivision, and by transverse is meant compartments bounded by transverse bulkheads. The subdivision in this direction is just as important as in the other, and the volume enclosed in any water-tight space should be inversely proportional to the distance of the compartment from the center of gravity of the ship. As the trim of the ship materially affects the maneuvering qualities, this rule is advanced in order that the trim will not be radically altered by the flooding of end compartments during an action. A sudden altering of the trim during the crucial period of battle might possibly be the factor upon which victory or defeat will hinge.
All of the main transverse bulkheads should be carried intact at least up to the height of the upper protective deck. By an intact bulkhead is meant one in which there are no openings other than manholes, and just as few of these fittings as possible. One of the chief causes of the loss of H.M.S. Victoria after the collision with the Camperdown, was the fact that doors had been cut in the main bulkheads, some of which could not be closed after the accident. It is considered much less dangerous to cut hatches in the protective deck than it is to cut doors in water-tight bulkheads, as water-tight doors, no matter how efficient their means of operation may be, are fundamentally a water-tight weakness.
The space below the protective deck should be subdivided as is deemed necessary by main transverse bulkheads, and to reiterate, these bulkheads should be left intact even to the point of making some parts of the ship inaccessible. This series of intact transverse water-tight bulkheads will divide the ship into a number of main parts and each of these subdivisions should be supplied with separate and distinct ventilating and drainage systems, each independent of any other. The space within any of these main subdivisions may be further divided by longitudinal bulkheads as is deemed necessary, but where these longitudinal bulkheads form large compartments at the sides of the ship, such as the compartments outboard of the explosion bulkheads referred to above, the corresponding compartments on each side should either be cross connected through the inner bottom by an equalizing trunk or an efficient flooding system should be supplied. The Borodino class of the Russian Navy had automatic flooding systems, but at the battle of Tsushima this system did not take care of the heel of the Souvaroff. From the experiences of this action, it would appear that any automatic system, however efficient on the surface, is liable to failure during the heat of battle, and that it would be better to correct any heel by flooding compartments on the opposite side through the fire main, the operation of which is under the control of the personnel.
The compartments housing the engines and the boilers should in fact be the only large compartments or spaces in the part of the ship below the upper protective deck. Some ships have centerline bulkheads fitted in these spaces, but a center-line bulkhead is fundamentally a source of weakness as regards the stability of the ship, and should be carefully avoided wherever possible. The tendency should always be toward broad and short compartments, rather than long and narrow ones. In twin screw ships, it is necessary to fit a center-line bulkhead to separate and isolate the two engines in separate compartments. This is necessary in order to avoid the danger of losing all units of propulsion by the penetration and subsequent flooding of one compartment. In the boiler spaces, however, no such necessity for a center-line bulkhead arises, and for safety no such bulkhead should be fitted. The boilers can be easily distributed among a number of transverse compartments, the sinkage caused by the flooding of one of which will not be nearly so serious as the heel given a ship by the flooding of a large side compartment that manifestly cannot be compensated for.
The water-line portion of a ship consists of that portion just above the upper protective deck in the region of the water-line. If a sloping protective deck has been installed this portion will be in a measure provided for. The triangular shaped space running along the side of the ship just above the sloping deck, should have a water-tight flat on top. Behind the upper and lighter part of the main belt, there should be a coffer-dam, and inside of this, longitudinal bulkheads as considered necessary. In towards the center-line of the ship there should be at least one water-tight longitudinal bulkhead. This bulkhead is necessary in order to guard the hatches to the boiler rooms that must lie cut through the protective deck.
The upper portion of the ship is of far less importance as regards stability than are the parts already considered. The subdivision of this part of the ship is necessary in order to protect the personnel and to minimize the effect of shell fire on the upper works. As the subdivision of this part of the ship is of but minor importance, no definite rules can be advanced and the subdivision should be undertaken with a view of best utilizing the space.
The above completes all that can be said in a brief discussion of the water-tight subdivision of a modern battleship. It may be tacitly assumed that the water-tight subdivision of battleships of the present day is efficient for protection against under-water attack, as up to the present time in this war no capital ship, with but one exception, has been sunk by a single torpedo alone. The exception is H.M.S. Audacious. It is not definitely known whether the loss of this vessel was caused by a torpedo or a mine, but it has been said that this vessel would have been saved if she had not had secondary gun ports on the second deck. These ports did not hold when the ship listed with the result that the ship was lost from inrush of water. The loss of this vessel is an argument against installing the secondary guns below the level of the main deck, as the gun ports are great sources of water-tight weakness.
C. Protection Against Aerial Attack
With the rapid advances made during recent years, and the impetus given by the present war to the improvement of airplanes and dirigibles, no design for the protection of future battleships would be complete without a consideration of the protection to be provided against attack by these craft. The part played by aircraft in the present war has proved conclusively that they are of immense value in operations on land and for scouting purposes at sea, but it is considered highly improbable that they will play any true offensive part in fleet actions of the future. Aircraft, while highly valuable for scouting and for fire control purposes, will not be able to inflict any great amount of damage to a modern battleship, due to the small lateral target presented by the deck of a ship from the height at which these craft must necessarily operate for their own protection. A bird's-eye view of a modern battleship presents but few truly vulnerable parts—smoke pipes and fire control stations being the most important. The best protection against aerial attack lies in anti-aircraft guns, and in the reduction of unprotected parts and the multiplicity of numbers above the main deck. The protective deck at the height of the upper edge of the main belt should be sufficient to keep bombs dropped from the air from reaching' the vitals of a ship. The chance of aircraft dealing a truly vital blow is indeed slim, the only danger being in the possibility of a bomb falling into the smoke pipe. The cross-section of the smoke pipe, however, is so small that this is considered an impossible contingency. Should it happen the effect of the blow can in a measure be minimized by fitting armor bars across the smoke pipe near the top in order to bring bombs to explosion before any vital parts can be reached.
No one of the three fundamental factors of battleship design has such a great effect upon the displacement and the linear dimensions of a ship as the speed. Naval Constructor R. D. Gatewood, U.S. Navy, in an article read before the Society of Naval Architects and Marine Engineers in 19 16, gives the following example to show the effect of speed upon the length of a ship. To quote his words, "In order to obtain high speed it is absolutely necessary to have length. To give a concrete example of this, assume that we desire 24 knots speed from a 30,000 ton ship. With a 690-foot length the speed could be obtained with about 40,000 horse power. Keeping beam and draft constant but shortening the length to 630 feet, there would be needed 50,000 horse power and at 570 feet over 80,000 horse power would be required; whereas, if we desire only 20 knots speed, it can be obtained on a 570 foot length with but little more than 40,000 horse power." Bearing in mind the above, and also remembering the fact that we are considering in this article ships under 40,000 tons, let us consider some of the aspects of speed in relation to strategy and tactics, as on the above displacement almost any battleship speed within reason can be obtained, without making any material sacrifice in either the armament or the protection.
As strategy is the science that determines when and tactics is the science that determines how battles shall be fought, it has been said that speed is of more value strategically than tactically. By this it is not meant that speed is of no value tactically but that it is not so much of an advantage as it would appear to be on the surface. The commander of a fleet having a superiority in speed should be able to choose the proper time and the proper place before engaging in a decisive action, unless there are circumstances and conditions which are beyond his control. With superior speed, he should be able to retreat or withdraw, if an action is not desired, or to force an action if he so wills. But such a superior speed, to accomplish this object, need not be a very high speed. All that is necessary is a one or two knot advantage over the enemy.
This same superiority in speed will be of advantage in any maneuvers that may take place preliminary to an action. It should give the choice of the direction of wind and sea, and if by any chance the fleet with the superior speed should also have the superior long range gun power, it can choose its own range, thus inflicting decisive blows upon an enemy while receiving but few hits in return. This latter claim for superior speed has been show by the late Rear Admiral A.T. Mahan, U.S. Navy, to be more or less of a fallacy. The speed of a fleet is the speed of the slowest unit. He showed that as long as this is true, and as long as the maintenance of a big gun range presupposes an avoidance of close action, to hold such a range there must be a withdrawal at all times, and such a withdrawal will entail the abandonment of any unit which may suffer a loss in speed. Such being the case, it is almost inconceivable for any commander to deliberately sacrifice any part of his offensive strength in order to maintain a more advantageous range.
Sir Cyprian Bridge in a paper read before the Jubilee meeting of the British Society of Naval Architects, showed by means of diagrams the effect of the speed ratio of two opposing fleets. He attempted to show that no matter what speeds the two fleets might have, the major part of all actions would be fought in column formation, with the two fleets steaming on parallel courses in the same direction. He showed that this would be the case by a consideration of the speed ratio alone without considering the gunnery or the fire control question except for maintenance of range. He showed that if the speeds of the two fleets were equal, the courses steered would be parallel straight lines, while if they were unequal, the courses would be concentric circles with the slower fleet on the circle of least radius, always turning away from the enemy. The diameters of the two circles will of course be dependent upon the ratio of the speeds of the two fleets. The above conclusion is based upon the supposition of an action on the open sea, where there is plenty of sea room and depth of water for the necessary maneuvers. The presence of land or shoal water would naturally have an effect upon such battle maneuvers as described above, and it is rather hard to predict what this effect might be. It would seem, however, that any close proximity of shoal waters should be of advantage to the fleet with the superior speed, as that fleet need not engage in action until the slower fleet is forced into a disadvantageous position. That this might not follow is equally true, as shoal water might offset any advantage of speed, and keep the fleet having such superiority from assuming any superior position.
Speed is such an abstract quality of a battleship that any discussion is rendered more or less difficult by the many aspects it can assume. Suppose, for example, that the ships composing a fleet had all been designed with the same speed. We would naturally assume that the fleet speed would be equal to the designed speed of the individual units, but such would manifestly not be the case. No matter what the designed speed of the individual units may be, the fleet speed at the time of an action will still be the speed of the slowest unit of the fleet at that time. The speed of a ship is dependent upon so many factors that are beyond the control of the designer, that it is not hard to appreciate the fact that the speed of the individual units will most certainly be different. The speed of a ship is directly dependent upon the condition of the ship's bottom as regards fouling, the quality of the coal or oil used as fuel, the condition of the machinery, the condition of loading, and the personnel, and that these conditions should be the same on all units of a fleet is beyond the realm of the possible.
Thus we see that speed, being dependent upon so many variables, can only be considered in a relative manner. In other words, in considering battleship speed, we should consider just what speed can be given a battleship without making any undue sacrifice in the armament or the protection of the ship. Is it necessary or advisable to construct high-speed battleships like the British Queen Elisabeth class, or is it only necessary to construct ships with a speed sensibly equal to that universally accepted at the present time as battleship speed, namely twenty-one or twenty-two knots?
It may be said that the line-of -battle fleet of any first line naval power will never consist of less than sixteen and possibly not less than twenty individual units. The enormous cost of present-day capital ships would prevent even the richest nation (and after this war has passed there will not be very many rich nations) from constructing more than a very limited number of ships each year. Assume for sake of argument that the first-line life of a capital ship is ten years. With this the case, it would be necessary to build at least two capital ships each year in order to maintain an effective fleet of twenty ships at all times. This may seem to be a very short life for a capital ship in the first line, but if we stop and consider for a minute just how few vessels there are that can be considered first-line ships which were in commission ten years ago, we will see that this is not a very strict requirement. If the life of a ship is taken as ten years, it is easily seen that two ships must be constructed each year to effectively maintain the fleet at maximum efficiency. Suppose that two ships are built each year and that twenty ships are at all times maintained in the fleet. Then there will always be two ships that are nine years old, two that are eight, and so on down to the latest pair that have just joined the fleet. In a fleet of this kind, with ships of different ages, it is only reasonable to assume that the older ships have lost some of their propulsive efficiency so that their speed will be at a half knot or possibly a whole knot less than what it was at the time they joined the fleet as new ships. If this is the case, we can sec that a certain percentage of the original speed of the individual units will be lost in the fleet as a whole. Again any great increase in speed would mean an enormous increase in the cost, and if only two ships are to be constructed each year, it would be ten years before such an increase would become felt in the fleet speed as a whole, resulting in paying over an entire decade for something the full value of which is not received.
From the above remarks it would appear better and more economical to restrict the speed of battleships to somewhere close to twenty-one or twenty-two knots. In an article published in the Proceedings of the Naval Institute for November-December, 1915, the writer attempted to show the need of a division of battle-cruisers to operate in conjunction with the main fleet. If this class of vessel is necessary, and I think it is, the needs of the fleet as regards speed can be supplied by these vessels, allowing the battleships to be of more moderate speed.
On the other hand, there have been many eminent warship designers, among whom is Professor Hovgaard, who have advocated at least a small superiority in speed over the ships of other powers, but there seem to be few if any authorities who advocate any such speed for battleships as twenty-five knots, as was given the British Queen Elisabeth class. Even the British appear to have considered this high speed a mistake, as the speed of their ships was reduced in subsequent classes. This class of ship was a mistake and a very costly one, because the value of the money spent to obtain the high speed will never be received, as this class of ship will always act in conjunction with other classes of ships in fleet actions, where the speed of the fleet will always be the speed of the slowest unit.
Battleship speed, like protection and armament, has advanced greatly since the days of the pre-dreadnought. The speed has not only increased from about eighteen knots to the twenty-one or twenty-two of the present day, but the propulsive elements have undergone the most radical improvements. The reciprocating engine of the past has given way to turbines, and the turbine in some cases has been connected through the electric drive or electric reduction gear to the propellers. Boilers have been improved and oil has been substituted for coal as fuel. All of these improvements have been made in order to reduce the weight of the elements of propulsion in order that more weight might be allotted to the armament and the protection, while still maintaining the same speed.
Hand-in-hand with the question of the speed of battleships goes the question of the endurance or the radius of action. It is almost a waste of space to state that battleships of 30,000 to 40,000 tons are not coast defense vessels. They are ships that are able to operate on the high seas in any kind of weather, as there is no guarantee that they will not be called upon to engage in action in almost any corner of the earth. With this the case, it is manifestly necessary to make ships in a sense more or less self-supporting, able to remain away from fueling stations and bases of supplies for protracted periods of time. To do this it is essential that battleships be given a great radius of action. Probably one, of the greatest advances in the speed and propulsive elements, with consequent increase in the endurance of battleships, was when oil was substituted for coal as fuel. The Royal Commission in England in 1914 found that the radius of action with oil was 40% greater than with coal.
Oil has many advantages, a few of which may he summed up as follows: 1. The evaporative efficiency of 1 ton of fuel oil is equal to from 1 ½ to 1 ¾ tons of coal, dependent upon the quality of the oil; therefore the weight of fuel carried can be reduced by from 30% to 40%, if the radius of action is kept the same. 2. There is a great saving in space as 1 ton of fuel oil occupies 38 cubic feet against 42-44 cubic feet for coal. Also spaces can be utilized for the stowage of fuel oil that are not fitted for the stowage of coal, such as the double bottoms. 3. The use of oil allows the complement of the ship to be reduced. It has been estimated that there is a saving of from 25% to 55% in the fire-room force. 4. Commander Dinger, U.S.N., has estimated that for a 20,000 horsepower plant, the use of fuel oil will require 40 tons less weight than if coal were used. 5. The production of steam by oil is very easy of control and is much more constant. Oil also gives clean fire-rooms, no ashes, and the boilers should last longer. 6. Oiling a ship is a much more simple matter than coaling, as oiling requires no manual labor by the crew. Again, oiling at sea is much simpler than coaling at sea, and if necessary, one warship can give fuel to another. It has been estimated that by the use of oil, the strength of the British Grand Fleet would be increased by 25%, as the ships could keep their station practically all the time.
Practically the only objections raised to the employment of oil as warship fuel are the cost of oil tank construction and the special ventilation that must be provided, trouble with oil smoke, and the loss of the protection that would be afforded by coal in the side bunkers of the ship, outboard of the boiler and engine rooms.
When one comes to analyze these objections we find that they amount to but very little after all. The cost of the construction of oil tanks is of course greater than the cost of the construction of coal bunkers, but the increase is not excessive and amounts to but a very small percentage of the cost of the ship as a whole. The objection raised on account of oil smoke has been surmounted by a better design of the combustion apparatus whereby more complete combustion is obtained with almost an absence of smoke. Again there may lie many times when the ability to make an oil smoke screen will be an advantage rather than a disadvantage. This has been shown most positively in the methods taken to protect convoys of ships passing through the war zone. The loss of protection afforded by the coal in the side bunkers is probably the greatest objection to the use of oil, but even this disadvantage can be nearly avoided by a better design of the under-water subdivision and the distribution of the protective armor.
Weighing the advantages and the disadvantages of oil as fuel, it would seem that the gains resulting from the use of oil greatly outbalance any disadvantages that may occur, that oil has proved itself the far superior fuel, and that as long as a plentiful supply of oil is available it is the best and the most logical fuel for warships.
Summing up, then, the question of speed and endurance for modern battleships, it would seem that the battleships of the near future need have but a very slight if any superiority of speed over the ships of other powers, the strategical value of speed being left as one of the cardinal virtues of the battle-cruiser. No sacrifice should be made in the armament or the protection in order to obtain increased speed. In the United States where there are vast resources of fuel oil, oil should be used as the fuel for battleships. If a certain radius of action is selected as a standard, the use of oil in place of coal admits of a saving in weight of the propulsive or speed factor of the design. If we can keep the same speed with a decrease in weight, it would seem that all else being equal, this saving in weight could be used to greater advantage by increasing the armament and the protection than by increasing the speed.
5. Concluding Remarks
The foregoing article has been written with the more or less express purpose of stimulating interest and discussion among officers, both line and staff, of the naval service. The author realizes that his rather brief experience in the service has not equipped him to see all of the questions from every point of view, and for that reason if for no other, he invites any criticism or discussion—constructive, destructive or otherwise—that anyone may care to make on any or all of the questions or points involved. Discussion will be welcome from anyone, but more especially so from the younger officers of the Navy. If interest resulting in discussion is stimulated among the younger generation of naval the author will not feel that this paper has been written in vain or without effect. We, the younger generation of the present, will be the strategists and the naval architects of the future. It is up to us to collaborate in intelligent study and discussion throughout the time that we are preparing for the day when the burden of upholding the prestige on the United States Navy will rest upon our shoulders, in order that we may bear that burden as well, if not better, than it has been borne in the past. Speak up! Let us hear your views on these vital points. Do not be bashful about expressing your opinions or ideas on paper, as no matter how radical they may appear, they are entitled to careful consideration in deciding what is best to incorporate in the designs of the future.
The preparation of such an article as I have attempted to write naturally entails careful study of much of the literature written on the subject. I have endeavored throughout the text to give credit where credit is due, but I am afraid that I have put down points without mentioning the source from which they came. However, as throughout the advance of civilization, knowledge and trains of thought have been handed down from the older to the younger generations, it is but natural that I have absorbed points of view that have not arisen with me. It would be a sorry world indeed if the children did not absorb the best ideas of their forebears. Many of the points I have set down I found in my notes, notes that were made during my course in the theory of warship design under Professor Hovgaard, at the Massachusetts Institute of Technology, and where I have made use of them I wish to give him due credit, for it was through his instruction that I made a start on that long journey that has no end, through the vast field of warship naval architecture.