DESIRABLE AND POSSIBLE REQUISITES OF THE BATTLESHIP BEST ADAPTED TO THE ITALIAN NAVY IN VIEW OF THE LESSONS THAT MAY BE DRAWN FROM THE MOST RECENT PRACTICAL RESULTS AND FROM THE PROGRESS OF INDUSTRIAL TECHNICS.
Before the Russo-Japanese war, it was considered desirable to have on board of battleships several kinds of guns for piercing the various thicknesses of armor; the heaviest guns represented that part of the armament destined essentially to be brought prominently into action on closing the distance. A speed of from 18 to 19 knots was held to be sufficient for battleships; Italy alone, holding fast to the opinion, rarely abandoned by her, desired for the said vessels a speed superior to that of probable adversaries; and it seemed that, travelling in this direction, the differences between battleships and armored cruisers were destined to disappear.
Now, the general tendency, represented by the English Dreadnought type, and in other navies by the latest plans of battleships, is principally marked by guns of one caliber and by high speed. The heavy caliber with high initial velocity is held to be necessary for the greatest exactness and efficacy in long range firing; the single caliber is demanded principally because it carries with it the greatest facility for fire control.
High speed is held to be necessary for battleships as a strategical and tactical factor.
*The Naval Prize Essay, published in the Rivista Marittima, supplement to No. VI, 1908.
To satisfy the all-big-gun conditions, the tonnage may vary between that which would correspond to a return to the single turreted monitor, and that of the huge battleship with many heavy guns; if it is found better to have on the same vessel 12 guns rather than 10, there is no reason for not preferring 14 to 12; the tendency is therefore toward an increase in tonnage, and it is impossible to say where it may be necessary to call a halt.
Even Austria, that owing to the moderate caliber thus far adopted for its battleships, and also to the small radius of action admitted as sufficient, had kept the displacement within modest limits, has now reached its maximum (14,500 tons) in the ships of the Radetzky type, now under construction.
While the general tendency is toward the single caliber, this is set aside by France and Austria-Hungary, who are arming their new vessels with guns of 305 and 240 mm.
This being understood, is it expedient for Italy to join the all-big-gun procession? Even admitting that such a course may be, in itself, rational, may it not be permitted to Italy to solve the problem of battleship types in a more economical manner than would result from adopting vessels of the Dreadnought type?
The life of heavy guns is very limited; could a nation with financial means as scant as our own profitably adopt a type of vessel, all the guns of which would have to be retubed after 60 rounds with full charges?
Admitting, because it is axiomatic, the necessity of constructing homogeneous divisions in a relatively short space of time, are the scant resources of our budget reconcilable with the construction of units each one of which costs not less than 50 million lire? And, if the single caliber mastodon is really necessary, is it rationally possible to devise an economical type yielding maximum returns? How, in such case, stand the limitations?
The replies to these questions constitute, in all essential particulars, the solution of the problem of the desirable and possible requisites in the type of battleship for Italy.
ARMAMENT.
The Different Types.—The greater the caliber of a gun, the flatter is its trajectory and the greater the residual velocity with respect to the gun of smaller caliber and with equal initial velocity; on the other hand, the latter has, on its part, the advantages of superior manageability and rapidity of fire. In other words, the heavy gun has among its chief advantages that of greater danger space, or the greater latitude admissible in the estimation of the distance, and greater efficacy of a single shot; the superior manageability of the other is felt in a seaway, and especially if it permits of keeping the gun continually pointed at the target; such gun laying is not yet possible in the mounts of the heavier guns; but these latter have already made considerable advance in appropriating to themselves all the characteristics of the rapid-fire arm, having regard to the systems of breech closure, of loading, of training, of return to battery, etc.
The principal ways that present themselves for establishing the armament of a vessel appear then to be the following:
I. To prefer manageability and rapidity of fire to the greater danger space and the efficacy of the single blow, which would be obtained in the highest degree by keeping within the limits of, medium caliber; it being possible to place on a vessel a large number of such guns, this number will compensate largely—in so far as regards the probability of hitting—for the smaller relative probability of each shot hitting. In order to fix the ideas, consider what this type of battery would mean to a vessel armed only with guns of 152 mm. or 190 mm., or to a battery of only 203-mm. guns, as in the Bettolo-Cuniberti type of 1899, considering the 203 mm. as taking the place of the 152 mm.
2. To apply the principle of the division of labor, by placing on one and the same vessel a few guns of heavy caliber and many of medium caliber; this is the well-known type of ship with four 305-mm. guns, and a numerous battery of 152 mm. or some similar caliber.
3. Seek out a compromise between the two foregoing systems, adopting a caliber between the mean and the maximum calibers, with the object of uniting the advantages of the two systems; to this type belong the new German vessels of the Ersatz Bayern class, armed with 14 guns of 280-mm. caliber.
4. Adopting in principle the preceding rule, but, not desiring to do away entirely with the gun capable of delivering a blow of maximum efficacy, give it part of the above-mentioned armament in place of a few guns of the compromise caliber; to this class belong the new French ships of the Danton type, having four 305-mm. and twelve 240-mm. guns, and the Austrian ships of the Radetzky type, with four 305-mm. and eight 240-mm. guns.
5. To adopt in principle the first type, with the addition of guns of heavy caliber; this type will bear the same relation to the first as the fourth bears to the third; to it belong our own vessels of the Vittorio Emanuele type.
6. To attribute great importance to the efficacy of every shot, without, however, entirely ignoring the importance of rapidity of fire, adopting the heaviest caliber with which we have succeeded in securing such perfection as to approximate its qualities to those of the rapid fire guns; to this category belong the English vessels of the Dreadnought type, and those planned or in construction in the United States, Japan, and Russia, armed only with 305-mm. guns.
7. Take a step still further in advance of the preceding by adopting the gun of the maximum caliber; to this category would belong the vessels armed with guns of a caliber greater than 305 mm.
It is to be noted that the nations that are now adopting the Dreadnought type of battery have already constructed vessels with batteries of the fourth type; thus England in 1905 launched the Lord Nelson type, armed with four 305-mm. and ten 234-mm. guns; Japan, the Satsuma types in 1906, with four 305-mm. and twelve 254-mm. guns; these navies did not believe that they could stop at these types that were for them but a transition to ships of the Dreadnought type.
In order to seek out the proper standards for establishing the type of battery most suitable to our battleships, we should fix the thought upon the importance of the various calibers. We may attempt to proceed in a theoretical way to the study of the probability of hitting, but the conditions of firing in naval battle are so complex that results obtained in that way are very elastic, the more so that, although admitting the existence of an undeniably rigorous process, this would always refer to the gun considered as isolated, whereas it is of capital importance to take account of the manner in which the various guns may be disturbed or favored by the action of others on board the same vessel.
No matter how uncertain and contradictory may be the data derived from the Russo-Japanese war, the change in the standards governing the types of vessels is nevertheless due to them, and is justly stated in the theme which we are endeavoring to examine. Let us then examine every one of the various parts of our study, remembering that the contradictions among the writers on the results of the recent war are not solely due to deficiency of the data; studying these opinions attentively, it is often found that they depend upon a desire to justify previous conceptions and affirmations. It is not rash to say that in deliverance from these preconceived ideas must lie a great part of the secret of a just approximation to the facts.
Recent Lessons.—For our present purposes the separate consideration of the injuries sustained by the different parts of each vessel, is not of so much moment as the formation of some judgment as to what may have been necessary to the putting of the vessels out of action by means of gun fire, and as to how the attainment of this object may have been possible in view of the firing distance.
The battle of August 10, 1904, is the one from which we may extract some data for determining the efficacy of fire at distances greater than 6000 meters.
In the initial phase developed at a mean distance of 11,000 meters, the fire was suspended after a few minutes by both parties, because it was a useless expenditure of ammunition.
The second phase of the battle was that developed at distances not less than 8000 meters; in this also the results of the firing were small; the only noteworthy effect of which we have any notice was produced upon the Russian protected cruiser Askold. The effect to which we allude was that of a projectile which exploded on deck near the base of the forward smokestack, the plates of which were driven in, causing a diminution of the draft, and the splinters, falling into the boiler connections, perforated their tubes, obliging the isolation of the corresponding group of four boilers; the injury was not of great importance because the Askold had five smokestacks.
It is not important, for the object which we have in view, to consider the injuries of the Askold; but in the case of this vessel we confine ourselves to offering, for whatever they may be worth, two observations: 1st, that the aforesaid effect, the sole result of the greatest distance phase, was produced by a projectile of the caliber of 305 mm.; 2d, that the number of chimneys was what prevented the Askold from seriously feeling the damage.
The third phase of the action was begun at a distance of 7300 meters; both adversaries sought to concentrate the fire upon the flagship, which was at the head of the line. Concerning the effects of the fire upon the Russian flagship, which was the Cesarevitch, we know that the most serious injuries, owing to which it was impossible either to follow the vessels that returned to Port Arthur or to attempt to reach Vladivostok, were:
(a) A shell that struck at the base of the foremast, passing through the right wall of the mast and exploding against the left wall.
(b) The damage produced by three shells striking the two smokestacks; the first made a hole, more than a square meter in size, in the forward smokestack, but the obturators remained intact and it was possible to continue the forced draft, the other two struck the after smokestack at top and bottom; the projectile burst while passing through the sides and riddled it over its entire height, rendering forced draft impossible, and enormously increasing the coal consumption.
(c) A shot under the armor on the starboard bow; the projectile burst on contact with the bottom, at the joint of two plates, of the outer plating, driving in plates, plate frames, and even the bracket plates; the bolts being broken owing to the driving in of the plates, the water entered through their holes, flooding the compartments adjoining the armored deck.
It is interesting to note that the five projectiles that produced the said principal injuries were of the caliber of 305 mm. and which, with others, struck the Cesarevitch during the phase of the action which took place at distances over 6000 meters, and before another projectile of 305 mm. exploded against the conning-tower.
Considering the total of the damage sustained by the Cesarevitch, it is found that the greatest effects were due to fifteen shots of heavy caliber, of which thirteen were of 305 mm., and two of 203 mm.; let these numbers be borne in mind in comparison with the number of the various kinds of heavy caliber guns which Togo had, that is, sixteen of 305 mm., one of 254 mm., and ten of 203 mm.; it would be absurd to make these numbers a basis of calculation, but they permit us to assert that the injuries sustained by the Cesarevitch, which, as is known, produced the confusion among the Russian ships and brought about their retreat to Port Arthur, are essentially due to guns of heavy caliber, and especially to those of 305 mm.
Naturally it is necessary to guard against a desire to generalize this result, which, in any case, is a single term in the sum of the considerations, of which the decisive ones are supplied by the battle of Tsushima.
As is well known, in that memorable battle, the Russians opened fire at 2.08 p. m., at a distance of about 6500 meters from the head of the enemy's column; the Japanese withheld their fire for about two minutes longer, at which time they were within the distance of 6000 meters. Togo writes in his report that at 2.45 p. m., the issue of the battle was decided; in truth the results obtained that day and during the night and day following are but the logical consequences of those produced in those first 35 minutes of firing.
In order to comprehend how this may have happened, we may ask ourselves: Is the result of the Japanese fire to be ascribed to the large or medium caliber guns? A superficial comparison of the situation of the two adversaries, limited to guns brought into action by the two parties, would be as follows: The Japanese had 56 heavy caliber guns against the Russians' 53; 305 medium caliber guns against 168; it might be observed that the Russians had, to a much greater extent than the Japanese, guns of an antiquated type, but, on the other hand, a greater number of guns of the maximum caliber, and besides, that at least a considerable part of the Japanese guns could not have been changed or retubed, and that hence they had corroded bores owing to the number of shots previously fired. The conclusion that in such case would appear logical would be that the two adversaries were about equal in the matter of heavy guns (if indeed the Russians were not superior), and hence the destructive effect of the Japanese fire would have to be ascribed to their great superiority in medium caliber guns.
Such a conclusion would seem to be confirmed by the fact that in the reports of the Russians mention is made of a hail of fire that covered their ships. But reasoning in this fashion we completely lose sight of a most important element, which is, the tactical situation of the adversaries. Concerning the movements of the squadrons there are no absolutely sure data to enable us to draw an exact plan of the movements, and we know that these certain data can never be had, because at the time of the action both parties were too much occupied to take exact account of them; but the plan based upon Russian statements, published by Lieutenant White, of the U. S. Navy, in the Proceedings of The U. S. N. I., and reviewed in the number of June, 1907, of the Rivista Marittima, is, for many reasons, believed to be nearest the truth. It permits the following deductions:
The object of the tactical maneuver of the principal forces of the Japanese (battleships and armored cruisers) united under the direct command of Togo, was that of maintaining themselves in positions practically equidistant from the enemy's leading vessel, concentrating their fire upon it. At 2.30 p. m., after 20 minutes of firing, when two battleships, the Osliabia and the Kniaz Souvaroff (that had been nearest the Japanese), had been obliged to abandon the line, while the Japanese guns were concentrating upon the Alexander III, the leading Japanese ship was about 5000 meters from the Alexander III, and their rear vessel about 4600 meters.
Thus the maximum difference between the distances at which Togo's ships executed their firing was 400 meters; on the other hand, while the leading Russian vessel was 4600 meters from the nearest part of the enemy's line, the other vessels were at greater distances, so much so that the rear of the line of principal forces was about 7200 meters distant, and the difference, 7200-4600, owing to the way in which the increase of the distance rapidly diminishes the probability of hitting, makes it plain to us how, by virtue of the tactical situation, even if between the two adversaries there had existed a parity of conditions from all other points of view, the fire of the Russians must necessarily have been less efficient than that of the Japanese.
It is therefore evidently established: 1. That the hail of fire must not be understood as expressing the action of the medium caliber guns, but the concentration of all the Japanese guns of heavy and medium calibers upon the nearest vessel of the enemy. 2. That in view of said concentration we cannot attribute to the medium caliber guns the virtue of having disordered and demoralized the Russian gun-pointers, preventing them from laying their guns well, because the Russian ships in the center and at the rear of the line enjoyed a relative tranquillity; but the gun-pointers were placed in conditions of inferiority by reason of the tactical situation. 3. The Japanese did not await the closing of the distance in order to open fire with their heavy guns, because, during the first 20 minutes of firing, the distance between the nearest points of the two fleets varied only from 5500 to about 5000 meters.
In view of these deductions, the question which we are now discussing is limited to the examination of the relative importance of the heavy and medium caliber guns on the vessel concentrating her fire.
After the first ten minutes of firing the Osliabia was constrained to draw out of the line. In the beginning of the action, a 305-mm. projectile struck the port bow at the water line, at a point where there was no armor belt, and, owing to the heavy sea, two forward compartments were flooded.
Another projectile of heavy caliber made a hole in a coal bunker, very probably facilitated by the displacement of some armor plate, and the vessel listed to port; three other projectile's struck the forward turret and one damaged the lower part of it, while the third shot, that struck near one of the gun ports, disabled all the turret crew by wounds or asphyxia. A violent conflagration (reported by Togo) was seen from the Japanese line to manifest itself on board of this vessel, which under such circumstances abandoned the fight. In order to keep her afloat (raise the shot holes out of water?) a few of the starboard compartments were flooded, but the vessel continued to sink by the head, the gun ports of the lower battery could not be closed on account of their condition due to blows received (an effect that may be attributed to the medium caliber guns) so that the vessel continually listed further to port and capsized at 3.10 p. m. After the Osliabia, the Japanese fire was concentrated on the Souvaroff, which had become the nearest ship owing to the Russian formation in single line; said vessel was obliged to draw out of line at 2.30 p. m., with injuries that are not well known; we know that she had masts and funnels shot away and a fire on board, and that later she received the coup de grace from the torpedo-boats. In like manner, the Alexander III, with a fire on board, left the line, afterwards returned to it and definitely left it, and at 7.07 (when the artillery battle had ended) Kamimura's armored cruisers, which were then operating separately from the battleships, saw her capsize and go down. Concerning the Souvaroff, the Alexander III, and the Borodino (that took fire at 6.40 and sunk at 7.23 owing to an explosion of the magazines) Ferrand observes: “qu'il est probable que l'artillerie pratiqua des .brèches sur ces trois bâtiments ; si l'on se souvient que la cuirasse épaisse était entièrement noyée, que la hauteur de la cuirasse mince de 152 mm. était, au moment du combat, au plus de Im. 70 à Im. 80 au dessus de l'eau, on admettra aisément que l'eau a pénétré sur le pont cuirassé par les brèches soit de la cuirasse mince, soit meme à cause de l'état de la mer et du roulis, par des brèches au dessus de la cuirasse. L'invasion du pont devait diminuer la stabilité déjà réduite."
The fate of the battle of Tsushima was decided by that of the four best Russian ships above recorded; the brief considerations set forth suffice to show that the principal effects of the artillery at Tsushima were the following:
1. Fires on board due to heavy and medium caliber guns.
2. Sinking of the vessels due to heavy guns, owing to the large openings produced by their blows.
3. Disabling of the guns, due essentially to the heavy caliber guns.
We admit, however, that in the production of the fires, a great part of the results may belong to the medium caliber guns, by virtue of the great number of shots fired by them; but it must be taken into account that this happened on board the Russian ships under special circumstances; indeed the said ships had been overloaded with coal, and it is chiefly to the coal in the higher localities that such fires were due. Is it just, then, to draw from this a general deduction in favor of medium calibers?
Moreover, attributing to the medium caliber guns the Osliabia’s inability to close her gun ports, this cannot supply us with an argument for keeping the aforesaid guns, because such a case would not arise with vessels having the guns in turrets.
A valid argument in favor of the medium caliber is the vulnerability of the chimneys, because, if the injuries of this kind sustained by the Cesarevitch were produced by guns of heavy caliber, that takes away nothing from the fact that the chimneys constitute the best kind of target for 6- and 8-inch guns; but before holding such an argument as sufficient for retaining these guns we ought to examine and see if there is not a way of rendering less dangerous this kind of injuries, that Mahan considers equivalent to the loss of a mainmast in former times.
Another fact is to be noted: those who expected to see the armor perforated as on the proving ground have been sufficiently disillusioned. In part this may be attributed to the bad quality of the Japanese projectiles and in part to the general obliqueness of the blows; well and good. Against a vessel characterized by great extension of protected surface we could expect important effects from our fire in two ways: by the effects of perforation or destruction, and by the disabling of the organs of the vessel; in either case heavy caliber guns are necessary.
Summing up, the conclusions that seem unassailably to follow from what (considering the limited space required) we have briefly alluded to concerning the employment of the artillery in the recent war, are as follows:
I. Maximum importance of the heavy caliber guns; the necessity of obtaining rapid effects at the beginning of the action is axiomatic, because the advantage that may be gained thereby is a compound advantage, owing to the manner in which the enemy is thrown into confusion when, for example, the ship that is leading his line is quickly put out of action; hence it is of the highest importance to have efficacious means for action at the maximum distance; this maximum efficacious distance will in the future presumably be superior to what it was in the battles of the recent war owing to the progress in arms and in the means of fire control; hence it is logical to admit that the importance of the heavier guns may be a growing one and not a passing phenomenon.
2. The necessity of leaving to the heavy caliber guns the task of deciding the action between battleships being established, there remains to be studied how this battery of heavy guns may profitably be composed, bearing in mind that the necessity of requiring the efficacy of the single shot, imposed by the results of the Russo-Japanese war, requires us to follow a different way from that defined by the types of battery distinguished by the numbers I and 5, or more definitely, by the types whose principal characteristic is the large development of the 203-mm. guns. It is unnecessary to say that this is far from constituting a censure for those types of vessels, for when they were planned they appeared to be for Italy the best of its battleships; that was true with regard to the vessels of that time, in the same manner that the ships to be constructed to-day should be able to cope advantageously with those already planned or that may be planned.
Having thus made a first limitation for battery types, it is proper to inquire if a certain number of medium caliber guns may not be necessary to the best employment of the heavy calibers in view of the defense against torpedo-boats. In order to proceed in this direction it is necessary to consider how the various battery types satisfy the requirements of fire control.
Battle Caliber and Regulating Caliber—It is acknowledged that the best of the range-finders for naval artillery to-day existing is the Barr & Stroud; the type generally in use at present is that with the base of 1.80 meters, that gives an approximation of 80 meters at a distance of 4000 meters; of 180 meters at 6000 meters, and 320 meters at 8000 meters.
This approximation is certainly not ideal, taking into account that if we consider a vessel 120 meters long, 22 meters broad and 9 meters high at a distance of 5400 meters (6000 yards), supposing the vessel to be inclined at an angle of 45° with the firing plane, the danger space has the values shown in the following table:
Angle of Danger space
Kind of Gun. fall. (meters).
152-mm. A. 91 Reg. capped projectile V. =680 m.s. 9° 47’ 61
152-mm. of the U. S. V.=730 m. s. 8° 30’ 69
305-mm. of the U. S. V.=730 m.s. 4° 45’ 117
The house of Barr & Stroud now announces a new range-finder having a base of 2.74 meters and an approximation of 40 yards at 6000 yards, and of 85 yards at 10,000 yards; such a rangefinder would hence be able to give the distance with desirable approximation. However, we must bear in mind a hard and fast principle.
Even if the range-finder should supply the exact value of the distance, the fire control should always be based upon observation of the shots.
This principle results from the fact that the firing distances, or rather those to be transmitted to the sight-setters, must necessarily be different for the various calibers, the regulating corrections (correzione di regime) being different, particularly owing to the not inconsiderable differences that exist between the data furnished by the explosive at the acceptance trial and the averages assumed for the range tables, as well as on account of the differences (we here set down the principal ones) between the temperature of the explosive and the density of the air during the acceptance trials and the values of these important elements at the moment of tactical action.
Let us now refer to the firing in naval duel, from which we will endeavor to pass to squadron fire control.
From the aforesaid principle there follows as a corollary the necessity of having either a single caliber, or two calibers, between which, however, the differences in the columns of water thrown up by the projectiles at the point of fall are such that they may not be confounded with each other; whoever may have to direct the firing of a vessel armed with guns of 240 mm. and 305 mm. (Austrian and French type) will surely see a wide dispersion of his shots owing to the differences in the regulating corrections, and he will be unable to reduce this dispersion because the differences between the columns of water thrown up by the projectiles of the two calibers will not be sufficiently sensible.
The convenience of the single caliber lies in these considerations rather than in those of an organic character.
A second principle of fire control is that which recognizes in long range firing the impossibility of estimating the misses; to understand this it is only necessary to bear in mind that, at a distance of 5000 meters, a longitudinal miss of +400 meters or —350 meters subtends, at the eye of an observer, elevated 20 meters, an angle of I'.
This being the case, there remains no other means except to base the improvement of the firing on the observation of the shots that fall short; consequently it is necessary that a considerable number of shots should strike simultaneously in such fashion as to form a rosette of shots, all fired with the same data. Rigorously, it would be necessary for this purpose to cause to be fired at the word of command a certain number of guns, greater than two, and to deduce, by theoretical rules, from the number of short shots, how far the center of the rosette is from that of the target, supposed to be lying flat.
In practice, firing by word of command, very logical with batteries composed of numerous pieces, naturally is not realizable with an armament of heavy caliber guns, and hence, independent firing is necessarily substituted, considering the shots fired within a brief interval of time as fired with the same data; in either of the two cases the improvement will be obtained without being theoretically hampered by a small number of shots falling short.
The methods of improving the fire are hence two in number:
The first seeks to regulate the fire of the heavy guns by observation of the fire of the medium calibers; as is well known, at any moment, from the range of the medium guns we may deduce the corresponding distance for the heavy guns, taking into account the relative regulating corrections of the two kinds of guns, these corrections to be determined not at the instant of battle, but from time to time (repeating the experiment with every fresh supply of ammunition) with the ship and target anchored, valuing as exactly as possible the differences between the misses, and bearing in mind the approximate rule that the relative regulating correction is proportional to the distance.
The second method is to improve the firing directly with guns of the principal caliber; this requires that the fire be continuous, the which includes rapidity of fire and a considerable number of guns of the said caliber on one and the same vessel; when these two conditions are wanting, recurrence to the first method is indispensable; in other words, it is necessary to make use of the medium calibers.
It must be remembered: 1. That the second method is not in conflict with the first, the great credit for which belongs to Commander Ronca, but it is a simplification of it permitted by the progress in materiel. 2. That the simultaneous application of the two methods is not excluded; that is to say that with an armament that permits the application of the second method, it might be a help to have a certain number of medium caliber guns, for this would permit of double control.
It being recognized that the task of deciding the action belongs essentially to a single heavy caliber, that we will call the battle caliber, the types of armaments, from among which, according to the foregoing, it remains to make selection, may be considered as divided into three categories:
1. A single heavy caliber uniting the double duty of battle caliber and a caliber for fire regulation; to make clear the idea, the armament that satisfies such a conception may be composed entirely of guns of 240 mm. or of 280 mm. (German type) or of 305 mm. (English type).
2. A single heavy caliber that satisfies the preceding conditions but with the addition of a medium caliber that lends itself to the constitution of the double control for fire regulation, and that may casually be effective against undefended parts; as well as adapted for anti-torpedo-boat action, with which we have not thus far occupied ourselves. This conception is satisfied by the new Japanese type (guns of 305 mm. and 152 mm.) and the American type (guns of 305 mm. and of 127 mm.).
3. A battle caliber that does not lend itself directly to improvement of the firing, and that would have absolute need of the assistance of a regulating caliber, as above; under present conditions, there would belong to this category a vessel armed with guns of a caliber superior to 305 mm.
The addition of medium caliber guns to those of battle caliber being here considered advantageous, it is necessary to qualify the argument in favor of medium calibers by repeating the principle of Sims, that "a large number of medium caliber guns is harmful to the fire of the heavy guns." This comes from the fact that the hot gases produced by the fire of sufficiently numerous medium caliber guns, produces refraction of the line of sight; that becomes positive interference with the firing, or a diminution of the volume of fire—by virtue of which, according to Mahan, the medium calibers should be deemed superior to those of heavy caliber—and a diminution of the exactness of the fire of the heavy guns.
If then, the medium calibers are to figure in the armament, their number must be kept sufficiently small and their positions subordinate in order not to disturb the battle caliber. Before proceeding further it is necessary to see if the conclusions now deduced can be maintained with regard to the fire control of united vessels.
This question is considered in relation to the tactical principle of the concentration of effort, or to the necessity that the various fractions of one and the same naval force seek to concentrate their offense upon one and the same fraction of the enemy, if not upon one and the same vessel, and that the vessels of the same fraction seek to concentrate their fire upon one and the same ship.
This principle, which has been recognized for a long time, was, at Tsushima, realized in the famous "hail of fire," with which we have already occupied ourselves; it implies considerable difficulty in the observation of the results. The questions that arise are the following: Of what use are the deductions previously drawn if it is going to be impossible to distinguish our own shots from those of another vessel? Will not the dispersion be so wide as to justify the French and Austrian type of armament with two heavy calibers?
Concerning shots fired by many vessels, which fall simultaneously about the target, it does not seem possible to carry out the observation of the short shots, since it is possible to befall that one ship may fire short, another too far, and that we may declare ourselves satisfied (with our performance).
If, however, at a certain moment, we may be able to render the fire observable as that of a single vessel, we may assure to ourselves such advantage also for the continuation of the fire. To this end it is necessary, in the same manner pointed out for the determination of the relative correction between heavy and medium calibers, to determine said relative correction between the heavy calibers of the different vessels. This being granted, the flagship A of the fraction of the naval force that is being considered, may issue instructions that he will open fire when he estimates himself at the distance X; in order that another vessel B may consider its own shots as composing a single rosette with those of the vessel A, it is necessary: 1st, that the measures of the distances of A and B from the enemy's vessel upon which they are to concentrate, may practically be considered as affected by the same error; 2d, that B apply on beginning the firing the relative correction of the guns of A. The first condition will not be satisfied by means of independent telemetric measures since the exactness of the telemeter will not be sufficient; but it may be reached in the following way, based upon the hypothesis that A has taken care, at that initial moment (or after a suspension of the firing) to place himself in such position as that the other vessels of his section may all see him, in order to measure exactly their distance from him. The vessel B measures with the telemeter the distance BA, and solves by means of alidades, the triangle having one side BA, another side X, and an angle formed by BA and the line BE, joining him with the enemy's vessel upon which concentration is to be made.
At the moment in which A commences firing, the side BE so deduced will be affected by an error, for size and for sign, identical with that committed by A's range-finder, when, as far as X is concerned, the error on AB may be neglected. The difference between the initial firing distance determined in the manner just explained and the distance from the enemy simultaneously furnished by one's own range-finder, will furnish each vessel with the necessary guide to the end that, the firing once commenced, this may be continued, basing itself upon the indications of one's own range-finder and on the observation of the short shots.
The possibility of carrying out such a system shows how arduous would be the problem of a good fire control of a naval force, when each vessel has more than one battle caliber; the arguments set forth for the case of an isolated vessel are therefore strengthened.
Fire Regulating Caliber and Anti-Torpedo-Boat Caliber.—The recent war has shown the absolute necessity of not leaving the anti-torpedo-boat guns unprotected, because in such case they will in all probability be put out of action during the combat between the vessels; it is sufficient to recall the fact that on the Gromoboi, after the battle of August 14, out of 24 guns of 76 mm., only two were still serviceable. It is proper to remark here (because this is in relation to the type of gun that we are seeking) that the protection may be realized in two ways: I. By mounting these guns only at the conclusion of the action between the vessels. 2. By keeping them mounted, but protecting them with a sufficient thickness of armor; for obvious reasons it is well that these medium guns should be the same as those that in the preceding paragraph have been considered in connection with fire regulation.
Restricting the torpedo defense guns to those of the first kind, we should have an armed vessel of the Dreadnought class, having guns of 305 mm., and guns of 76 mm. with arrangements for dismounting; but it is clear that we must keep mounted at least a considerable number of 76-mm. guns, because otherwise a day attack of torpedo-boat destroyers would certainly succeed, and hence it would be necessary to resort, as the English have done, to the expedient of having the torpedo defense guns very much scattered, so that the bursting of a single shell could not dismantle a large number of them at one and the same time. Such an arrangement is not acceptable because it keeps the anti-torpedo-boat guns unprotected; therefore we must have recourse to the second of the two systems above mentioned, employing the first as an auxiliary, that is to say, in order to intensify the defense against nocturnal attacks.
There is necessary then, besides the heavy caliber guns:
I. A caliber adapted to the regulation of long distance firing, for action against the unprotected parts of vessels, and against torpedo-boats. Evidently it must be a gun whose rapidity of fire and precision at long range is sufficient for the purposes above mentioned; hence it must be a gun of medium caliber. The caliber will be determined, as we shall see, in relation to the number of guns of this kind.
2. A caliber smaller than the preceding, having the exclusive task of repelling torpedo-boats; as they are not to be kept in position during the combat between ships, they must be easily manageable for mounting and dismounting; they must therefore be of small caliber.
Selection of the Heavy Caliber.—A fundamental idea that ought to guide us in all the various questions of the theme that we may unfold, is the following:
The problem would be dealt with in a one-sided manner if we should limit ourselves to studying our type of battleship in relation only to the most recent vessels of other navies, or even if we should propose to ourselves only to reach such results that a group of these vessels might confront in the best manner a group of ships of the aforesaid type; it is necessary instead that the type of vessel should be considered in the more general way imposed by strategical and tactical exigencies, or considering the action of the group, the requisites of which we wish to determine, in relation to the conduct of the fleet already existing.
Since we are now to discourse concerning the armament let us note that Austria, until the new vessels now planned, has held it sufficient not to advance beyond a gun of 240 mm.; we have deemed necessary a superior heavy caliber.
This being understood, in order to fix the ideas of the points of advantage of having a superior heavy caliber, let us consider, for the Armstrong guns of 305 mm. and 254 mm. (which we may hold to be about equivalent to the 240 mm.), the maximum angle of incidence R with the normal, at which they are able to perforate modern Krupp plate of 152 mm.:
Distance in meters. Guns of 305 mm. Guns of 254 mm.
3000 43° 35°
6000 39° 25°
Note—The above numbers are calculated with the formula:
R = 2 arc cos V0
3 V
in which V is the residual velocity at the distance considered, and Vois the velocity necessary for the perforation of the plate with normal fire (calculated with the Krupp-De Marre perforation formula) ; the formula reported is no other than the well-known one of Louel that gives good results in proving ground practice.
These figures show us how, as between two vessels A and B having the same thickness of side armor, the ship A which has the superiority in maximum caliber can permit herself to bring B a noteworthy number of degrees nearer abeam than the other can do without greater risk; this difference becomes more marked as the distance increases.
If now we consider the Austrian types of battleships we find: 1st, that the Monarch types have 15 cm. of side armor; 2d, the Habsburg types have 100 mm. abreast of the coffer-dam and 135 mm. on the casemates of the 152-mm. guns; 3d, the Erzherzog types have above the belt a thickness of from 120 mm. to 150 mm. 150 mm.
Taking into account these thicknesses of armor, and the field of fire of the guns, we find that an Austrian vessel when engaged in a struggle with a vessel armed with 305-mm. guns, in order to fire with the maximum number of her guns, will be obliged to present her side in a direction in which it will be vulnerable.
It is remarked that in the simple case of combat between two vessels, it is easy to maneuver so as to keep the bearing of the enemy between a direction which limits a sector of maximum offense, and the direction nearest the beam in which the side is least vulnerable to the enemy's more powerful guns, this latter direction to be determined by the impossibility of perforating the armor which covers the greater part of the side. The wider the angle between the two directions just mentioned, the greater the liberty of maneuvering of the vessel under consideration. In squadron combat the inclination of the single vessels will be of secondary importance compared with the advantage of having all the vessels in good tactical position; for example, in position to T, or in positions equidistant from the nearest part of the enemy's line: the advantages of position of the kind that Togo secured at Tsushima are greater than the risks represented by a few vessels that expose this armor normally.
In any case, the smaller these risks, the greater liberty of maneuvering the fleet will have: whoever, then, has the superior caliber will be in the better conditions.
If the maximum caliber adopted for the new ships of the other navies were that of 240 mm., we might be able to discuss the propriety of accepting for our own the gun of 280 mm.; but, given the armament of the new types, we are limited in our choice to the gun of 305 mm. or to one of still greater caliber, since we may not select an inferiority, disadvantageous for the reasons before given.
It is necessary at this point to keep in mind the recent progress made in artillery. The 240-mm. Skoda gun has peculiar excellencies that up to now have not been realized in guns of superior caliber; the progress to which we allude consists precisely in the extension of these excellencies to the 305-mm. gun. With the wedge breech closure and the charge contained in cartridge cases (of which the fabrication has so far progressed as to present the desired requisites) the 305-mm. guns destined to arm the new Austrian ships possess very noteworthy conditions of safety, rapidity, etc.
The caliber of 305 mm. is, at the present time, that which unites the maximum efficacy of the single blow to the characteristics of a rapid fire arm. To go beyond this caliber would be, on our part, a renunciation of these excellencies; the gun of superior caliber that would be adopted, in order to possess a high initial velocity, would have a shorter life than the 305-mm., and we may say at once that a heavier ship would be required. The argument in its favor would be that of maintaining in our types that superiority in caliber they have had until now with regard to those of the Austrians, but we may say that our type armed with guns of 305 mm. will always have that superiority with respect to the Austrian battleships which precede their newest type, and that even in this respect there will exist a superiority in the desired sense, because on our part we shall have an armament of 305-mm. guns, while in the Austrian and French types appear also the 240-mm. guns. Consequently it is at present neither necessary nor convenient for Italy to go beyond the caliber of 305 mm.; that may be accomplished in the future if our probable adversaries themselves adopt for their future types the all-big-gun armament of 305-mm. caliber, and if the heavier guns become more manageable.
Having thus selected our battle caliber, the next question is naturally the following:
How many guns of 305 mm. ought to be placed on our type of vessel, and how should they be distributed?
Principles of Concentration (of Artillery Materiel) and of Maximum Return.—When the ram had the character of the predominant tactical arm, it was logical to consider the number of the ships as constituting in itself an important factor of victory.
As the principal task belongs to-day to the gun, in order to determine if it may be profitable to concentrate one's own artillery in a restricted number of units, without referring to the tactical details which we will discuss in Chapter II, it will suffice to fix our minds upon the advantageous tactical situations which we have already pointed out in connection with the lessons of the recent war. In general it may be affirmed that, the object of tactical maneuvers being the concentration of offense upon one part of the enemy, this concentration will be so much the more easily obtained the more the means of offense are assembled in a few units.
As an illustration we may observe that an advantageous tactical position is that in which our ships execute their firing, being all at approximately the same distance from the enemy's vessel upon which they are concentrating; if we have a certain number of guns assembled in one and the same vessel A, we are on that account in better condition than if we had the same number of guns divided between two vessels B' and B", because these two vessels would have to obtain by maneuvering the advantage that A obtains by construction; if the ships of the A class maneuver well, it will be easier for them to secure the desired tactical position than it would be for ships of the B type.
Therefore we are brought to admit the convenience of having ships with as many guns as possible; it must, however, be observed:
1. That having a certain number of heavy ships instead of a greater number of small ships, the effects of the enemy's offense are more sensible, that is to say, the enemy, concentrating his offense upon one of our vessels, disturbs the fire of a greater number of our guns, and the loss of a unit signifies the loss of a greater fraction of the whole.
2. That, consequently, the smaller the financial resources of a nation, and the more the theater of war in which its forces must operate lends itself to the employment of torpedo-boats, so much the more must it recognize the necessity of placing itself only conditionally in the path leading to concentration of offense in a few units.
For economical, tactical, and strategic reasons, in the type of battleship for Italy, we ought to establish a compromise, weighing in the balance the value of concentration, and that of distribution; to the end that this compromise may not be established in an arbitrary manner, we must have recourse to the idea of the maximum return.
For this purpose it is sufficient to remember:
(a) That the advantages of having as many guns as possible on one and the same vessel depend not at all upon the number of guns in an absolute sense, but upon the number of guns that can fire simultaneously upon the same target.
(b) That a vessel will generally have a single target to fight.
(c) That for battleships the development of offense in the broadside sectors is of greater importance than ability to fire in the line of the keel.
These three axioms concur in causing us to seek for the heavy caliber guns a distribution which permits to every one of them a field of fire on both sides of the vessel; the third in particular makes us bear in mind the necessity of providing in a special manner for the broadside fire; but as the relative potentiality of the broadside fire and of that in the direction of the keel, varies with the amplitude of the lateral sectors of maximum offense, we must ask ourselves if there may be logically established a limit for this amplitude. It would be irrational to limit the development of the fire in the direction of the keel below what is compatible with said limit, holding to which, we may, given a certain number of guns, distribute this number in the most rational manner. This being granted, the third axiom will lead us to determine the armament with maximum return on the basis of the following rule:
The increase of the number of guns is rational so long as it increases the potentiality of the broadside fire, but if there exists a limit, beyond which the increase in the number of guns favors only the fire in the direction of the keel, that limit ought not to be exceeded, and it is likewise not profitable to remain below it.
Amplitude of the Sectors of Maximum Offense.—In the naval duel as well as in squadron combat, it is very desirable to be able to impose the fighting distance which is deemed most advantageous; let us here occupy ourselves with the requisites necessary to this end in the naval duel, leaving it to the second part of this study to determine if the characteristics decided upon for our type satisfy the conditions of combat between assemblages of ships.
It will be of assistance to keep in mind the axiom that in Chapter II will permit us to solve the problem of the best fighting distance; this says that in this problem it would be absurd to pretend to seek a fixed number and to demonstrate, for example, that 5200 meters is a more advantageous distance than 5100. Truly the elements which must be taken into account are varied and complex; consequently, instead of a fixed value for the distance, we ought to seek out the limits between which it is best that the distance be included, or in other words, we must know if it is better to fight at long range or at medium range.
This being granted, the hypotheses that may be made concerning the maneuvers of the enemy, in order to deduce the necessary and sufficient amplitude of the sectors of maximum offense for our ships, are the following:
i. The enemy's vessel N has our vessel I in a sector of maximum offense.
2. The vessel N has I in line with the keel.
In the case of the first hypothesis, in order to be sure of being able to impose the distance, it is necessary to have at least one of the following advantages:
(a) Greater speed.
(b) Greater amplitude of the sectors of maximum offense.
At first sight it may seem preferable to seek to obtain the condition (b) because speed is a very costly element; but let it be noted that for a number of tactical and strategical reasons, of which we will speak in their turn, there is required for our type of vessel a speed two knots greater than that of the types of the most probable adversaries; hence we may be sure of being able to impose the distance if we have sectors of maximum offense about the same as those of the aforesaid types.
Now it is well known that in the new French and Austro-Hungarian types the 240-mm. turrets are at the sides, and that, just as in our ships of the Vittorio Emanuele class, the forward and the after turrets have a field of fire of 135° from the line of the keel; thus in these vessels the sectors of maximum offense cannot be extended beyond about 45° counting from the beam.
In our type of vessel, with regard to the hypothesis of the broadsides battle, we may then hold sectors of 45° counting from the beam, to be sufficient.
Let us now consider the hypothesis that N has I in the direction of the keel, and let us put the question: Would it be possible for I to impose the distance, keeping N in a sector of maximum offense? The speed of I being 22 miles, that of the Austrian type 20 miles, and that of the French type 19 miles, the amplitude a of the sector under discussion (counting from the beam) would be given by the formula Sin a=Vn
Vi
or it would be equal respectively to 89" 40' and 59° 50'. The first of these amplitudes is absolutely unattainable, and hence against a ship of 20 knots speed, the maneuvering of I must alternate the bearing in the direction of the keel and that in a sector of maximum offense. In this case, then, the question is answered negatively.
As an illustration, let us suppose that I wishes to fight a ship of 20 knots' speed, keeping the distance between the maximum distance at which the fire is effective and a distance (minimum) of 2000 meters.
The duration of each period of end-on battle, which would depend only on the difference of speed, would be about 33 minutes; the duration of each period of broadside combat would vary with the amplitude of I's sector of maximum offense, and, for amplitudes of 45°, 60°, and 70°, would be respectively 10 meters, 21 meters, 51 meters. But it is to be observed that if the enemy's vessel is being chased, the ship I, when it has given up the end-on fire in order to reach the amplitude of 60° or 70° of the sectors of maximum offense will be obliged to remain for the first 33 minutes in a very disadvantageous position; as the amplitudes just mentioned would evidently require the arrangement of all the turrets on the longitudinal axis, the inferiority of our type could not but be very sensible; hence the fact of the possibility of being caught in this position of great inferiority, reduces to a secondary place the advantage (otherwise very questionable) that, with amplitudes of 60°, we should have with respect to the French type, being able to impose the extreme fighting distance.
It should be stated here that the reconciliation between an amplitude of 60°, counting from the beam, in the sector of maximum offense and the potentiality of the fire in the direction of the keel seems to be reached in the Michigan type of the United States, all four of whose turrets, each one containing two 305-mm. guns, are on the longitudinal axis, but four guns can fire in the line of the keel, owing to the different heights of the emplacements. In this system, each of the turrets nearest the center of the ship stands higher, and, therefore, is heavier and exposes a larger target than would be the case with turrets of which the guns were all on the same level.
Aside from this, such an arrangement involves the inconvenience of the interference of fire already mentioned in connection with the fire of the medium caliber guns in relation to those of heavy caliber; this might be remedied by salvo firing, but it is well understood that the commandant of each turret must have autonomy in order to carry on the fire of his guns.
Among the desirable and possible requisites in the armament of our type of vessel, let us then place the following:
I. Strength of fire in the direction of the keel that can compare with that of the new French and Austrian types.
2. The turrets should be placed so as to have a field of fire on both sides; but, as we exclude the case of the guns of one turret firing over those of another, it is necessary that some of the turrets be removed from the longitudinal axis.
3. Sectors of maximum offense extended to 45°, counting from abeam.
Distribution and Number of the Heavy Guns. (See Plate I.)—Since the armament of our vessel is composed of guns of 305 mm., these should be placed in pairs in turrets, because it is well recognized that the two-gun turret represents the best compromise between the advantages of the concentration, and that of the dispersion of the heavy artillery.
We must now inquire in what way the armament composed of a certain number of two-gun turrets may satisfy the condition previously deduced, to which may be added the axiomatic condition of having the same strength of fire before and abaft the beam, because naval tactics teach us that there exists no plausible reason for desiring the contrary.
This being granted, for the vessel with two turrets, not wishing to limit the fire in the direction of the keel to two guns only, it would be necessary to place the turrets on a line inclined to the axis, in a way that would be a return to the Duilio types; it is clear, however, that such an armament is not the one with maximum return that we are seeking.
For three turrets, the ideal arrangement would be on a diagonal, with a fire of six guns in the direction of the keel and six guns in the broadside sectors; but such an arrangement is evidently not practicable while the motive power remains as at present. In general, whatever may be the armament, we may exclude the possibility of arranging three turrets on the same diagonal. In the report presented this year .to the "Institution of Naval Architects" by the member McKechnie, on the theme "The Influence of the Engines upon the Artillery of Modern Battleships," we find a sketch of a vessel with five turrets, three of which are on a diagonal; but the author considers that this would only be possible if gas motors were adopted and chimneys abolished. This idea being excluded, the ship with three turrets must then have the emplacements on the longitudinal axis; placing, however, the middle turret near the forward one, we shall have a greater field of fire forward of the beam, and it will result analogously if the middle turret is removed toward the stern.
On this account, in order not to limit the fire in the direction of the keel to two guns only, and owing to the fact that in passing from six to eight guns we increase the broadside fire, we arrive at the vessel with four turrets.
To the end that the disposition of the artillery of this last vessel may respond to the conditions already established, it must needs be that shown in Fig. A, Plate I, that is to say, with two turrets placed in the usual way on the longitudinal axis, and two placed laterally on a diagonal. Reserving to ourselves the right to investigate this arrangement later on, let us notice how, at first sight, it is capable of permitting a broadside fire of eight guns and a fire in the direction of the keel of six or four guns, according to whether or not it is possible to fire No. 2 astern and No. 3 ahead.
In a vessel with five turrets, not being able to place the fifth on the diagonal with 2 and 3, we are obliged to put it on the longitudinal axis, but, a priori, we know that, leaving the other four turrets arranged as in Fig. A, the vessel would be excessively long; we are, therefore, obliged to remove turret No. 3 toward the bow (or No. 2. toward the stern), placing it abreast of No. 2, and limiting the field of fire of these turrets to one side only. In this way we have the arrangement shown in Fig. B, which arrangement is that of the Dreadnought.
It is stated that in the Dreadnought the turrets 2 and 3 can fire directly astern; if this were not so, the vessel with ten guns would be inferior to that with eight guns, since she would be able to fire astern with a single turret only; and as there is no reason for thus sacrificing stern fire to that of the bow, or vice versa, such an arrangement is to be condemned. If then it is a fact that the turrets Nos. 2 and 3 in the English types can fire over the stern, the same possibility must be admitted for the turrets bearing the same numbers on the ship with eight guns; so that the ten-gun vessel has the same potentiality of broadside fire as the eight-gun vessel, and no improvement is made on the arrangement in Fig. A.
In the ship with six turrets, the disposition is that which would result from placing turret No. 4 of Fig. B at the side, and locating the new turret abreast it on the other side, as shown in Fig. C. This vessel could fire with eight guns on each side, and with six in the direction of the keel. While, from what we have said, the passage from the ship with four turrets to one with five, is not logical, either from the point of view of broadside fire, or from that of fore and aft fire, the ship with six turrets is logical when owing to the arrangements of Figs. A and B, the impossibility exists of firing with turrets 2 and 3 astern as well as ahead. Consequently the passage from the vessel with four turrets to one with six turrets is rational only if the fore and aft fire of the vessel with four turrets is deemed insufficient.
To obtain an increase of broadside fire over that of eight guns in Figs. A, B, C, we must have recourse to the vessel with seven turrets, thus obtaining the disposition shown in Fig. B (Ersatz Bayern); the increase of another turret brings the arrangement of Fig. E, or that of the Danton, which maintains the potentiality of fore and aft fire unaltered, that of Fig. E bearing the same relation to Fig. D as the arrangement of C bears to B.
Summing up, the potentiality of the fire in relation to the number of guns is shown by the following table:
Number of guns. Fore and aft fire. Fire in sectors of maximum offense.
8 4 or 6 8
10 6 and one end 8
2 or 6 at the other end
12 6 8
14 6 at one end 10
2 or 6 and the other end
16 6 10
From the foregoing it results that the armament giving the maximum return, which we are seeking, is that with four turrets disposed in the manner shown in Fig. A; the advantage over this arrangement that might be attributed to that of Fig. B (Dreadnought) would be that, for example, in the case of the disabling of turret 2, the vessel might present her port broadside and continue firing with eight guns; but the Dreadnought type would have no advantage, if, instead of one of the turrets 2 and 3, one of the others was disabled. In order to have a real advantage in this sense, it would be necessary to recur to the arrangements of Figs. C and E. Hence the choice must be made between vessels armed with 8, 12, or 16 guns. The preceding discussion establishes the fact that, for Italy, the vessel with four turrets is the
best.
Arrangement of the Four Turrets.—With modern emplacements, a turret with two guns of 305 mm. can fire beside another in the same plane (past it, and in the same direction with it), or in a slightly different plane, when the distance between the planes passing through the centers of the turrets parallel to the plane of fire, is seven meters.
Since for various reasons easy to comprehend it is important to us to have the turrets Nos. 2 and 3 of Fig. A, Plate I, at the least possible distance from the longitudinal axis, this distance must then be seven meters, and, considering the radius of the armored tube to be 4.50 meters, the transverse section of the vessel abreast the said turrets must measure at least 2 x 7 plus 2 x 4.50=23 meters.
It is besides important that the turrets Nos. 2 and 3 be as near as possible to the center of the vessel, because, if proposing to ourselves the contrary, we hope to reduce to the minimum the weight necessary for protection by forming two redoubts containing respectively the turrets I and 2, and 3 and 4, on the other hand in the manner just mentioned, we accomplish a better distribution of the weights, and we increase the possibility of having a fire of six guns in the direction of the keel. In order to determine the maximum value of the angle B between the diagonal 2-3 and the longitudinal axis Fig. 1, let us consider the right-angled triangles: 2KO and 23P, in which, designating the angle 23P by Y, 2K = 2P=3K’= 7 meters.
B+Y≤ 45°
The value of B which we are seeking is B=30°, and the corresponding value of B+ Y=44°, or we have a field of fire of about 46°, counting from the beam. In order to fix the idea, let us note that this gives the distance KK' as about 25 meters.
Given this disposition of the lateral turrets, those on the longitudinal axis, to the end that they may permit to the former a fire in sectors of 45°, should be at a distance from the center of the vessel of. not less than 26 meters; if these turrets were further removed toward the extremities, their field of fire could be greater than 270°.
It being thus established that our type of vessel should have two turrets on a diagonal inclined 30° to the longitudinal axis, and two turrets on the said axis, let us now settle the armament of medium and light guns.
Guns of Medium and Small Caliber.—If we were obliged to limit ourselves to a single heavy caliber and an anti-torpedo-boat caliber, it would be necessary to have recourse to the 100-mm. gun that is the heaviest with which semi-automatic working is possible.
* Having, however, recognized the necessity of a gun of medium caliber adapted for the regulation of the fire and for daytime action against torpedo-boats, it is necessary, as we have already said, that the guns of this caliber be protected by a sufficient thickness of armor, adequate for the conditions of long range combat. They must be arranged in a way that will not disturb the fire of the heavy caliber guns, and hence they should be located on a plane below that of the 305-mm. turrets, should be few in number, but with a wide field of fire. The arrangement in casemates does not satisfy these conditions; we must avoid a repetition of the case of the Osliabia, and the arrangement in turrets is necessary. We should have, then, four turrets, so disposed that each pair of them may be able to fire in the direction of the keel as well as in the sectors of maximum offense (a field of fire of 135° from the longitudinal axis); each of these pairs of turrets is to be placed in an intermediate transverse section between an extreme and a central one of the heavy gun turrets. Given this arrangement, since there is required in the medium caliber gun to be adopted precision in long range firing, we maintain that it is best to have on our type of vessel eight 152-mm. guns of the new model of 50 calibers, that hurls a projectile weighing 45.4 kilograms, with an initial velocity of 930 m. s. and of which the rapidity of fire may be worked up to ten shots a minute. Since the French, as well as the Austrian, ships of the types already constructed have many parts unprotected, it will be very opportune to make up the armament (of our vessels) in this manner.
* The 102 mm. gun exhibited by the Armstrong firm at the Exposition of Milan hurls a projectile 14 kilograms with an initial velocity of 869 m. s., and has practically the same rapidity of fire as the 75 mm. gun.
Finally for the guns of small caliber, having the exclusive task of defending against torpedo-boats, with arrangements for dismounting, it is necessary to adopt the heaviest caliber that answers to these requisites, in order to obtain the maximum exactness of fire and the maximum efficacy of the single blow; an armament of twelve 76-mm. guns seems to answer the purpose well, these guns being placed, half of them in the extreme bow, and half at the extreme stern.
It may be objected that the eight 76-mm. guns that are on deck at the stern and on the forecastle of the Dreadnought, and that are to be removed from position during battleship action, have shown that the frequent mounting and dismounting of these pieces causes a too rapid deterioration of the carriages and sights. Several propositions have been made for the elimination of these inconveniences, among which is that of the adoption of disappearing carriages. There is no doubt that a solution can be found.
Ammunition Supply.—It is calculated that at Tsushima the Japanese fired on an average 75 shots per gun of heavy caliber; the number of shots fired by each one of the 305-mm. guns must have been less than that. At any rate it is better to take this number as a basis for establishing the allowance for each piece for combat between ships, than to take into account only the rapidity of fire. It is admitted by all to-day that a naval battle will not be an affair of ten minutes, but it must be remembered that when we say that at Tsushima the artillery battle lasted from 2.08 to 7.23 p. m., that is very far from meaning that every vessel fired uninterruptedly.
Moreover the battle is substantially decided by the putting out of action of the principal ships; no matter how much better protection these ships may have than those that fought in the last war, yet the increase in offensive means by the concentration of heavy guns presented by the new types should make us abstain from exaggerated opinions. With this we desire to say that from the guns will be required the maximum effort, that is to say, the maximum rapidity of fire with the best projectiles, only in the aforesaid initial phase, that is effectively also the decisive phase of the battle, because all the rest is a logical sequence.
An ammunition supply kept within reasonable limits in order not to overload the ship, and answer to the necessities of war, seems to be the following:
Guns of 305 mm.—One hundred rounds, of which 75 are capped projectiles with high explosive charges, and 25 are projectiles adapted for coast operations, but capable on occasion of being fired with battering charges; for this purpose these last 25 projectiles should have not only an equal number of full charges, but also a certain number of battering charges, to for example.
Guns of 152 mm. and of 76 mm.—Given the task assigned to these guns in the vessel of the new type (differing from that in other types already existing), the ammunition supply should be composed of H. E. shells. In order to have the greatest flatness of trajectory these projectiles should be discharged with the highest initial velocity; it is a question of the careful study of projectiles and explosives. We may hold it sufficient to have 250 rounds for each 152-mm. gun, and 300 for each 76-mm. gun, taking into account the fact that in general the guns on both sides will not be simultaneously in action.
Torpedo and Ram.—There remains to be defined the equipment of our vessel with respect to the other two naval arms.
We can have no illusions concerning the outcome of torpedo discharges from a long distance; in order to have a sufficient probability of hitting it is not enough to increase the run, because we must bear in mind the effect of an error in estimating the speed of the enemy.*
*Letting S denote the half length of the target, c the run of the torpedo, V its speed in m.s., the error in m.s. in the estimation of the speed of the target in order to hit it, must not bet greater than
?=Vs.
c
The new turbine torpedo of the United States, that has a diameter of 254 mm., has a speed of 28 miles per hour for a run of 3200 meters, and a speed of 36 miles for a run of 1100 meters. The corresponding values of ? are respectively 0.3 m. s., and 1 m. s. We must then, besides the radius of action, increase also the speed of the torpedo in proportion to the run, to the end that the same error may correspond to the same missing distance S. In order to have with the most modern type of torpedo above mentioned with 3200 meters' run, the probability of hitting corresponding to 1 m. s. of error in the estimation of the enemy's speed, the torpedo would need to have a speed of 104 miles per hour. In the present state of things the sufficient probability of hitting a vessel in motion with a torpedo must then be considered as from a distance of about one kilometer. An argument that would remain in favor of the long discharge would be that a torpedo discharged at a ship that formed part of an assemblage, if it did not hit its target, might hit another neighboring vessel. But we ought to reflect that if a number of vessels are arranged in single line, the distance between ships of 300 meters or more is sufficient to eliminate such chances, and we must hold that a torpedo discharged at a definite vessel would either hit that vessel or it would hit nothing at all.
The under water launching tubes cannot be destroyed in a long range action, and remain always a powerful means of offense on closing the distance, and also the most efficacious last resort of a vessel unable to move.
May we exclude close action? This form of struggle being that in which the unforeseen has the greater dominion, it may result the most opportune for whoever must place his greatest hopes in the unforeseen, or for the party that desires to reverse the fortunes of long range battle, or that a priori knows that he is unable to fight advantageously at long range owing to material inferiority or minor ability. Nevertheless this inferiority will not be admitted a priori; furthermore, even when one of the adversaries may believe that he has the greatest aptitude for close action, the hope of proving superior to the enemy in maneuvering and in firing will make him first attempt the long range combat. Consequently, only after a long range action will the party who feels his situation to be the worst seek close action; his adversary will seek to avoid that form of action.
Unless the combatant placed in conditions of inferiority possesses superior speed, close action cannot be obtained; without need of running the risk of torpedoes, a vessel or an assemblage of vessels has in its artillery the means of giving the coup de grace to an adversary.
If then we were reduced to desire a close action, the torpedo armament would not enter effectively into action, whenever, although we have the superior speed, the enemy can succeed in keeping us a considerable time under fire before we can succeed in closing the distance; it is not well, however, totally to suppress the under water launching tubes, because otherwise the enemy could, by closing in, more easily give us the coup de grace with his guns, while we should be able to act in such fashion that the enemy, in so doing, would risk compromising the advantage he had obtained.
The conclusion at which we arrive is that of reducing the outfit, as have Austria and the United States, to two lateral under water launching tubes, capable of discharging a torpedo with the ship at high speed, because the study of tactics demonstrates the necessity of this condition.
As for the bow tube, the torpedo guide (guidasiluri) is not sufficient to make it trustworthy with the run at an angle, and only Germany and Russia have adopted it; the stern under water tube exists in the new and newest English, Japanese, German, and Russian types, but if we analyze the question of the increase of radius of action of the torpedo, due to the enemy bearing astern, it is found that the increase is illusory, and hence, in order that a stern tube may be held to be necessary, we must imagine a case that is too improbable, that of a ship absolutely stopped.
As to the ram, there is to be considered:
1. The scant probability of ramming; it is easily demonstrated that no matter how little mobility it may have, a ship may always succeed in changing a direct blow into a scraping alongside.
2. That a close struggle will rarely be seen.
3. That the modern ship does not need to attempt to ram.
For these reasons, the possibility and the convenience of abandoning the ram is to-day well recognized.
Protection against Artillery.—In order to draw deductions in this regard from the recent war, it is necessary to place the systems of protection face to face with their performances. The reliable data that we possess are few, but nevertheless they are sufficient for the following observations of a general character.
The Russo-Japanese war has confirmed the necessity of a complete waterline belt. It is sufficient to recall the cases of the Osliabia and of the Asama; it is well known that this armored cruiser was obliged to withdraw temporarily from action because three projectiles had struck her astern near the waterline. It concerns us now to ask: Is the necessity of sacrificing to the protection of the waterline that of the higher parts—the French opinion—demonstrated or not?
Whoever has observed the Russian battleships of the first Pacific squadron must have noted how far they were from having the lines provided for in their plans; thus, for example, the heavy belt of 400 mm. of the Poltava types, to which the protection of the upper parts was so greatly sacrificed, was in great measure a dead weight.
The same thing occurred on the vessels that fought at Tsushima; according to the reports of Commandant Klado, on leaving Libau, the upper edge of the belt in the four ships of the Souvaroff type was only 60 cm. above the water. As this was the case with the normal coal supply of 1750 tons, Engineer Ferrand justly observes that on going into battle, when the coal supply was 2500 tons, the armor belt was entirely submerged and the protection was reduced to that of the 150-mm. armor, extending 1.70 meters above the water.
Naturally we may place against such occurrences the affirmation that the plans of the ships ought to be studied carefully so that, on going into battle, they may not have conditions so different from those called for as the Russian ships had, but for this purpose it is necessary for the waterline belt to have a height that may permit the draft to vary between rather ample limits. Also, aside from the hypothesis that a vessel may have several compartments flooded, whoever is obliged to fight far from his own bases (as may be our case) should foresee the necessity of having on board the maximum supply of coal.
All this shows that, the necessity of protecting the vital zone of the waterline being admitted, we must seek to increase the height of the protected surfaces, while it would be a great mistake to limit too much the said height in order to increase the thickness of the armor.
The recent war has demonstrated the necessity of reconciling the French type of protection, that looks essentially to the protection of the waterline, with the Anglo-Italian type, that limits said protection in order to have a continuity of protected surface in the central part of the vessel. Said necessity was already recognized, and the protection of vessels for the past few years has followed the idea; the war, then, has given us nothing new in this respect; however, the difference between the two above mentioned still substantially exists, because if we all agree concerning the parts to be protected, doubts arise concerning the thickness of the armor.
The results, the causes of which we must seek out, are thus briefly summed up: It has been possible to keep modern type cruisers (those of the Japanese) very usefully in the line with the battleships; in general the perforations that were looked for have not been effected. How can this be explained? An explanation may be found in the inclination of the plates to the plane of fire; if we look at the drawing of White above cited, it is perceived that at Tsushima the firing was executed under conditions very different from those of the proving ground.
Ferrand observes that this explanation does not suffice: "Un projectile de rupture pésant 340 kg. et capable de perforer 4000 m. une épaisseur de 456 mm. d'acier harweye, devrait défoncer, sous une incidence quelconque, des plaques de 100 mm. ou de 150 mm. Si aucun cas ni de perforation ni de défoncement n'a été observé, il faut on déclarer la faillité de l'artillerie, ou plutôt se demander si le canon et le projectile japonais étaient tels que nous le figurons." The excellent French engineer does not take into account the way in which the resistance of the plates increases as the angle of incidence departs from the normal; the formula of Louel, already mentioned, and upon which we may base ourselves because the practice of the proving ground confirms it, tells us that a plate of the thickness s, exposed normally to fire, is about equal, so far as concerns the effects of the firing, to a plate of the thickness s
3
that receives the blow at an angle of 40°. There may be established under such conditions the equivalence between 450 mm. of armor and 150 mm. inclined. This serves for the plane armor, and as for the curved armor it is very difficult to give it a normal blow; the inclination is then an element to be kept very much in mind; the poor quality of the ammunition, which seems to be confirmed by both the adversaries, should have contributed to this.
This being granted, how are we to protect our vessels against capped projectiles of heavy caliber and of the best quality?
We must now consider the armor ordinarily inclined to the line of fire; only exceptionally will it be found exposed to receive the blows normally; and this will be for fleeting instants, if our maneuvers are inspired by sane tactical criteria. Thus, for example, even when we consider the hypothesis of vessels passing each other steaming in opposite directions (logically and strictly, in close battle only), the moment in which the beam is presented will be but a passing one. Shall we seek to put ourselves in condition to remedy this exception? No, because solution is impossible; even admitting the possibility of having plates capable of resisting the guns, we can only protect a very limited portion of the ship; the weight thus employed would be, in great part, a dead weight under ordinary conditions, or with the vessels inclined to the line of fire, because it is clear that a defensive weight greater than is needed, is a weight that gives no return. Therefore, the rule for determining the thickness of armor based on perforation with normal fire is not to-day applicable, owing to the development of the heavy calibers, and battle studies demonstrate that even aside from this it is to be abandoned; this brings about a limit rule which would be the adoption for the guns of a caliber like that of the Duilio's guns, with the hope of being able, with a normal blow on the armor, to put the enemy's vessel out of action.
It is better to resolve to secure relative invulnerability under ordinary conditions, and this recognition of the general obliquity of the blows does not militate against the use of capped projectiles, because if the cap is useful under angles of incidence approaching the normal, it is not disadvantageous with oblique firing, and hence it is better to adopt it in general.
Let us denote by s the maximum thickness of armor that the enemy's heaviest gun can perforate at a sufficiently short distance, say 1000 meters; from what has been previously said, deeming 40° the average angle of incidence we can admit that the thickness s
3
may satisfy the case of oblique fire at any battle distance whatever. For the gun of 305 mm. (which is at present the heaviest on the French and Austrian vessels), the thickness s
3
thus determined gives 150 mm.; in order to have a margin of safety, let us adopt armor of 200 mm.; there is no reason for exceeding this thickness in any part of the vessel, while the maximum caliber of the guns of our probable adversaries does not increase.
Deeming these 200 mm. quite sufficient as well for the flat armor plates as for the curved ones of the 305-mm. gun emplacements, this limit may be exceeded for the conning-tower in view of the small increase in weight that it represents and of the importance of protecting the brains of the vessel; for the turrets of the 152-mm. guns, however, in view of their secondary importance, we may decide upon the minimum limit of 150 mm. In a general way the system of vertical and horizontal protection to be adopted is that of the Vittorio Emanuele type with the reduction of the central portion of the belt from the thickness of 250 mm. to that of 200 mm., and with an increase in thickness at the extremities from 50 mm. to 100 mm. In this way we maintain the valuable feature of the Vittorio Emanuele, that of having a considerable height protected by 200 mm. of armor, and by increasing the thickness of the bow armor we protect the high speed which has formed and must form one of the essential characteristics of any type of vessel adapted to Italy's needs.
In order to protect the high speed it is necessary also to seek to diminish, with respect to the vessels already existing, the vulnerability of the smokestacks.
We cannot, under present conditions, suppress them entirely during action; in order to do this it would be necessary, as Ferrand proposes in his report above cited, to have funnels to be lowered during action, closing their passages, using forced draft, and making the smoke conductors discharge through the side. But in the discussion of the aforesaid report by the "Association Technique" it was justly observed that with this system there would be created about the ship an asphyxiating atmosphere besides not having room above for the necessary horizontal conductors.
The already cited cases of injuries to funnels suffered by the Askold and the Cesarevitch in the battle of August m makes us reflect:
1. It would be desirable to have numerous funnels, but with the adoption of the heavy caliber battery, in order not to obstruct the field of fire of the gun on both sides of the ship, it is well to limit the funnels to two well separated from each other. 2. For battle purposes it is necessary to consider the forced draft as normal and to protect the funnels below the obturators with at least 10 cm. of armor.
The upper part of the funnels should be of very thin plates, and, since the tendency to-day is toward the adoption of a single projectile, armor piercing and exploding, supplied with delayed action fuze (as is made necessary by the extension of the armor plating on the new types), we may hope that generally we may not have explosions on impact with such plates.* in any case it is still necessary that the armor plating of the funnel should extend a little above the obturator, up to an armored grating, in order to avoid the fall of splinters. The strength of the draft will permit the reduction to the minimum of the section and height of the funnels.
*We may hope for this in fighting against a vessel armed with heavy caliber guns only; this makes it so much the more necessary for us on our part to have guns of 152 mm. that can fire projectiles capable of bursting against such plates.
Protection against Under Water Weapons.—The protection of the bottom against submarine weapons still awaits solution, that is absolutely necessary owing to the probable action of submarines in the next coming war and owing to the effects of torpedoes in the Russo-Japanese war.
We have discontinued the use of torpedo nets, and even in the navies that still keep them opinion is not favorable to their use when under way; we must seek to load down our battleships as little as possible, and hence it is not well to have on board of them such means of protection but on board auxiliary vessels that accompany the fighting forces.
With a ship in motion, the greater its speed, so much the more is it defended against automobile torpedoes, owing to the smaller probability of success in launching. Taking into account the action of the various kinds of torpedoes we will indicate in the second part special cruising formation for battleships.
As for anchored torpedoes, the possibility of there being opened, with due diligence, a passage through a mined zone is not to be excluded, but, notwithstanding this, every battleship represents an element so precious and of such relative importance that it is imperative directly to protect its bottom, replacing the present double bottom, useful only in cases of stranding.
In the battleship Cesarevitch the protection against torpedoes was obtained by bending down the armored deck. When the vessel was torpedoed on the night of February 8, 1904, the under water armor was driven in but not broken; nevertheless, four compartments were flooded, and the defect of this system of protection stands out in the fact that it did not protect large spaces from being flooded through a leak in the outer plating.
Whatever the system of armor plating of the bottom such mishaps could not be avoided. Indeed the armor plating may be held to be useless unless it is placed inside at a sufficient distance from the bottom, because its theoretical basis is corroborated by the way in which the effects diminish the farther the center of explosion is from the vital structure of the vessel. But to accomplish this either the transverse sections of the vessel are greatly increased and there is a great loss of speed that cannot be said to be compensated by the gain in stability of platform, or recourse is had to a very considerable thickness of armor which has a much greater weight, and the displacement of the vessel increases, as is well known, about three times that weight. In order that it might be possible to place armor able to resist submarine weapons at a sufficiently short distance from the bottom, it would be necessary to have found an adequate structure to be substituted for the present double bottom; but then we may confide the defense solely to this structure and lay the armor aside. This last is the way in which it seems that the protection of the hull should be sought, bearing in mind that the effects of the explosion are undoubtedly greatly diminished when, as Ferrand observes, the gases of the explosion have free way upward.
The study of this internal structure more capable of resistance than that in use at present is laid upon the engineers of all nations, and it is very comforting and flattering to us that Engineer Cuniberti affirms that he has already solved the problem. (See articles entitled: "A New Ideal Ship," published in Fighting Ships of 1906-07.)
In order to establish the standards concerning the maximum speed to be sought for in the type of battleship, it is sufficient to reflect how our strategical problem presents itself, considered under the two general hypotheses of the offensive and the defensive.
Whenever we may find ourselves in the case of having to fight far from our bases against a weaker fleet, it will be to our greatest interest to give decisive battle as soon as possible; there can be no doubt that the enemy's interest would be directly the contrary, on account of the wear and tear of our vessels due to the lack of permanent and temporary bases for the heavy ships, and owing to the diminution of force due to the conditions in which we must accomplish our coaling operations.
The methods to which the supposed enemy's fleet could have recourse would be reduced to the two following:
1. Undergo a blockade, remaining in one of his principal bases.
2. Regulate his action by the standard of the maximum activity compatible with the inferiority of his forces, utilizing special conditions of the seat of operations, keeping himself in positions previously prepared, having various exits, and hence capable of conferring a probability of success on a maneuver on internal lines, whenever our forces divide themselves in order to watch the different outlets.
It seems logical to hold that the second method would be the one applied at the beginning of the war. On our part it would be necessary to put ourselves in condition to surprise the enemy, depriving him of the possibility of fighting us singly, and the following distribution of the battle forces would be required: (a) the main body in position to threaten the enemy's communications with the more important of his principal bases; we risk nothing in presuming that, generally, this would apply also to the exigencies of land and sea co-operation; (b) in a central position with respect to the exits of the interior basin in which the enemy is found, maintaining a squadron of contact capable of refusing tactical contact with the main body of the enemy, but otherwise capable of maintaining strategical contact. The most profitable strength for this squadron may be determined in time of peace by keeping count of the present composition of the forces of a supposed adversary and of his vessels under construction. Let us suppose, for example, that we may deem sufficient for this purpose the division of the four armored cruisers of the San Giorgio type. A condition evidently necessary for the main body of the Italian forces would be the capacity to attack the enemy although diminished by the aforesaid armored cruisers. When, then, the San Giorgio division establishes strategical contact, then the main body, on information from it received directly or indirectly, should move against the enemy. In all this the speed assumes decided strategical importance, as it would assume whenever the enemy, owing to our action in the interior basin, must lean for support on one of his principal bases, in such a way as that we may blockade him. A naval force that blockades another in the ways imposed by the present means of war has the greatest interest in arriving in sight of the enemy as quickly as possible; the attainment of its objective is so much the more assured the greater is the speed of the single divisions, which gives us confidence in our ability to impose contact, cut off from their base hostile reconnoitering divisions, etc.
We have enlarged somewhat on the strategic condition of the offensive because there is no doubt of the importance of speed when one is restricted to strategic defense.
The strategic importance of the speed being in general admitted, it is also necessary that our type of vessel have superior maximum speed (an essentially tactical factor); but as in the new French and Austro-Hungarian types there is also an increase of speed over that of preceding types, the problem of maintaining on our part the advantage of speed is more difficult than in the past, less easily reconcilable with the other offensive and defensive requisites that are necessary for our vessel.
Bearing in mind, then, that the attainment of a speed above 20 knots is not irreconcilable with the offensive and defensive requisites that we have deduced, but that nevertheless it constitutes a very difficult problem in engineering, we are constrained to content ourselves with an advantage that, although sensible, does not require too much; consequently, let us establish the speed at 22 knots, because, as we shall see in Chapter II, such speed gives us confidence for tactical undertakings and because it is not difficult to understand that an advantage of two miles in speed may be an indispensable minimum in the strategic field.
In fact the maximum speed that we have already called (as is the general rule) a tactical factor, because it can only be maintained for a few hours, that is to say, during a combat, may often become a strategical factor in restricted seas. If, for example, we are maintaining a blockade, one of the notable advantages of the blockaded is that of being able to come out at the moment that he may deem opportune, and if he develops the maximum speed it may enable him, we not being ready to do likewise, to gain a sufficient distance for the forcing of the blockade. If the maximum speed that can be developed by our forces were equal to that of the enemy, it might, owing to the initiative that the adversary has in the operation, practically result in less speed; it is indispensable, then, that we have a certain advantage, to the end that in the worst hypothesis we may have equal speed.
The speed that, generally speaking, has strategical importance is that maintainable for a considerable period of time; we may call the strategic speed that of three knots below the maximum. The strategic speed of our type of vessel would be (22 knots being the maximum) equal to the maximum speed of the Danton type, and a little less than that of the Radetzky type. This represents an unquestionable advantage, and it is well to reflect that the common affirmations of the impossibility of maintaining a high speed for long periods can no longer be entertained; it is necessary to remember that high speed, besides being an engineering problem, is a problem of the organization and training of the engine room personnel, and to bear in mind that the English in the grand maneuvers of 1906 have shown that they have fully solved it by obtaining from the ships of the King Edward class (of 19 knots maximum speed) a speed of 17 knots maintained from noon of June 28 to the morning of the 30th.
This important result is to be attributed also to mixed combustion; indeed, it is well known that the New Zealand that used coal only was obliged to fall behind the other ships.
It would be very practical to use liquid fuel entirely; as Engineer Cuniberti has written, the various kinds of this fuel, being very refractory to any explosion of mines and torpedoes, are useful also from a defensive point of view, since they may be kept in deposits near the keel, forming the new structure for defense against submarine weapons, and from which deposits, with the aid of pumps, it would be easy to transfer it to the various boilers. “But it is a fact that at present there are not yet sufficient deposits of petroleum in all the points of supply, and, therefore, mixed combustion is made necessary, still keeping the coal as a defensive reserve. Indeed, a subdivided coal protection near the boilers of every group of turbines may be useful for absorbing at least a part of the energy of the gases due to bursting mines." *
* Cuniberti : "Mines and Turbines," in Rivista Marittima, December, 1906.
This being so, it is important to determine the requisites to which our ship must answer in regard to fuel supply; it does not seem difficult to establish a standard on the basis of which it could be found in a satisfactory state under the most difficult conditions that can logically be foreseen.
Under the hypothesis of the strategic offensive that we have already set forth, until we succeed in acquiring an opportune temporary base, the main body of our forces would have to be kept cruising. The study of the conduct of our fleet under such conditions being outside the subject, let us limit ourselves to observing that we may meet events with so much greater security if our vessels have requisites that may satisfy even the extreme case that our cruising vessels are obliged to establish refueling turns at a principal base situated at the greatest distance that can logically be foreseen. Naturally, these turns should be established for each strategic unit, because it would be absurd to be simultaneously deprived of vessels of equal type. Granting that we construct four vessels of the new type whose requisites we are studying, their coal supply should satisfy the condition of having only one vessel absent.
The main body of the forces must stand ready to develop the maximum speed, or keep the maximum number of boilers lighted and cruise at reduced speed, so as to have the minimum consumption of fuel. Let us call this the blockading speed, to which, by our calculations, there may be assigned (to have safe margin) a mean value of 10 knots.
The run from the main body to the base and return must be made at a speed sufficiently high to meet the interests of haste, but, on the other hand, sufficiently moderate, considering the great consumption of fuel at high speed and the necessity of not excessively exhausting the personnel and materiel. This passage speed may be established at 16 knots.
The vessels' total supply of fuel, then, must be equal to the sum of the following quantities:
1. Quantity C, necessary in order to move at the speed of 10 knots for three times the length of time T that a unit employs in going to the base, refueling, and returning; representing the time necessary for the run, at the rate of 16 knots, from the main body to the base by T1, and the time necessary for refueling by T2, we have T=2T1+T2. 2. A quantity C2 necessary to move the vessel at 16 knots' speed for the time 2T1. 3. A quantity C3 as reserve for strategic operations, that may be held to be that necessary in order to run about half the distance from the main body to the base at the strategic speed of 19 knots. 4. Reserve C4 for battle that may be set down as that necessary for six hours' steaming at full power.
Considering the Mediterranean and the various basins that it forms, from the peculiarly Italian point of view, as well as from the more general use of geographico-strategical conditions, we find that, in the said sea, a fleet may be obliged to establish turns at refueling at a principal base at a distance that will presumably fall within 500 miles.
In order to calculate the quantity of fuel with sufficient liberality, let us, then, call the distance from the main body of the fleet to the base 500 miles, which determines C1, C2, and C3; we may besides place T2=10 hours. The value of T becomes 73 hours, hence our vessel must travel:
219 hours at 10 knots per hour.
63 hours at 16 knots per hour.
13 hours at 19 knots per hour.
6 hours at 22 knots per hour.
Being able to say that, roughly speaking, the displacement of our vessel will be about 16,000 tons, we may calculate approximately the indicated horsepower at maximum speed, which gives 24,000, as well as the indicated horsepower for the other speeds under consideration, and deduce the corresponding values of C1, C2, C3, and C4.
All this admitting as usual: 1. That the indicated horsepower varies as the 2/3 power of the displacement and as the cube of the speed. 2. That the consumption of fuel, taking liberally into account the auxiliary machinery, etc., may be held to be 0.0012 tons per horsepower-hour. In this way we obtain:
C1=601 tons.
C2=710 tons.
C3=245 tons.
C4=175 tons.
Total:1731 tons.
Roughly speaking, we should then have a fuel supply of 1775 tons.
PARTICULARS.
The principal characteristics of the type of vessel that suits us being determined upon, we may say that we have sufficiently developed the first part of the subject, which calls for, not the study of a plan for a vessel, but that of the desirable and possible requisites for our type of battleship.
Before attempting to estimate the necessary displacement, it will be well to make a few brief observations:
1. That the arrangement established for the battery is not in conflict with that of the engines and boilers. Indeed, turbine motors are to be preferred, because—as is said in the English memorandum of constructions for 1906-1907—although they may have at the present time a few inconveniences, they have nevertheless many advantages; among these, there are of the first importance that of the reduction of the number of boilers, and that of permitting the subdivision of the engines, instead of requiring the wide spaces needed for the reciprocating engines.
2. The general aspect that can be imagined for the type of vessel deduced from this study is that shown in Plate II, and is briefly as follows: A forecastle forward with a 305-mm. emplacement, on a lower plane the two central emplacements, and astern, the other heavy caliber emplacement. On the broadsides, with a field of fire ahead and astern obtained by means of hollows in the upper works are the four 152-mm. emplacements.
Between the two central 305-mm. emplacements the field of fire is entirely clear, while between each of these and the corresponding extreme emplacements there is a bridge-house on which are the boats and from each of which rises a funnel, a mast, and a conning-tower.
The masts are naturally tripods, and, as in the Dreadnought, they serve as uprights for the derrick booms and support the military tops for fire control, that in this arrangement are inconvenient on account of the near neighborhood of the smokestacks; but it would not be possible to arrange otherwise unless we remove from the longitudinal axis either the funnels or the masts, in which case the field of fire would be obstructed.
We must not enter into a discussion of the details of the conning-tower, but it is necessary to observe that in battle it is necessary to be able to steer by bearings, and hence the helmsman must be able to keep the adversary bearing in the sectors of maximum offense (45° forward and abaft the beam).
Résumé of Requisites. Displacement.—The reply to the first part of the theme may be thus synthetized : The type of vessel best for Italy is one armed with eight guns of 305 mm., eight of 152 mm., twelve of 76 mm.; protected with a large extension of armor having a thickness of 200 mm. to 100 mm., having a maximum speed of 22 knots, with radius of action answering to the most difficult conditions that can be looked for in our seas.
The requisites deduced do not result from the idea of establishing a compromise between the various elements, but from that of obtaining a maximum return from every one; in other words, every one of the requisites demanded for the proposed type is a necessity which we may not remain without. Consequently we may not build a vessel smaller than that which is necessary to unite these requisites, and a larger vessel would constitute a bad use of our financial resources.
Let us now endeavor to estimate what may be about the displacement D of the type proposed.
For the weight Wh of the hull complete with all furnishings and marine fittings we may say, Wh=0.39D.
For the weight of the armament, including emplacements, their protection, and the ammunition in the proportions already indicated we have:
For the 305-mm. guns 1881 tons.
For the 152-mm guns 789 tons.
For the 76-mm guns 57 tons.
Torpedo tubes 20 tons.
Total 2747 tons.
For the weight of the armor let us observe that in the Vittorio Emanuele, deducting the weight of the emplacements, we have for this weight about 3090 tons, and that, reducing the thickness of the armor from 250 mm. to 200 mm., and increasing to 100 mm. her 50-mm. armor, as has been established for the type of vessel under discussion, this weight would be reduced to 3009 tons, the displacement becoming 12,400 tons. Since we may say, roughly speaking, that for equal distribution and thickness the weight of the armor varies proportionally to the 1/3 power of the displacement, we have for the said weight Wa=3275 tons.
For the weight of engines and boilers, since we may call 0.080 ton the weight per indicated horsepower, we have Wm=24,000. 0.080=1952 tons.
Finally, from what we have already set forth, the fuel supply may be put down at 1750 tons. The equation of the displacement then is
(1—0.39) D=2747+32751952+1750;
from which
D=15.950 tons.
Although this number can only be said to be a rough estimate, it serves to fix the idea, showing how the proposed solution may lend itself to reconciling for Italy the financial exigencies and the new naval exigencies.
The percentage of weights for this type of vessel should be as follows:
Hull and Armament. Engines and
fittings. Ammunition. Protection boilers. Fuel.
Gun protection.
39 17.2 20.5 12.2 10.9
CRITICAL EXAMINATION OF THE CRUISING ORDERS, MANEUVERS, AND FORMATIONS BEST ADAPTED FOR MAKING TACTICAL CONTACT WITH A NAVAL FORCE COMPOSED OF SHIP OF THE ABOVE SELECTED TYPE, AGAINST A SUPPOSED ADVERSARY OF EQUIVALENT FORCE.
As in the determination of the characteristics of the new type of vessel, so in the study of its tactical employment it is necessary to approximate to reality by studying this employment in relation to probable adversaries and to our fleet already existing; it is, moreover, necessary that we do not limit ourselves to considering the combat as an act in itself, but as a consequence of preliminary acts.
In order to follow these rules, it is best to transport ourselves to a field that, while being general, nevertheless permits of the estimation of the particular values of our new type, examining:
(a) The approach of two hostile naval forces.
(b) The most suitable cruising order in the neighborhood of an enemy.
(c) The formations and the initial maneuvers of battle.
In developing these arguments we have considered the mode of bringing about tactical contact, and we may study the tactical employment, properly so called by considering it under the following subdivisions:
I. Single duel between a vessel of the new type and one of the Danton type, or of slightly superior speed. It is obvious that a duel of this kind can very rarely happen, nevertheless the study is very useful because it serves to lead the way to ulterior considerations.
2. Combats between homogeneous groups, considering the types to be as stated above. On this point we may consider that we have developed the proposed theme if we confine ourselves strictly to its statements; but to properly fix the thought upon the tactical aptitudes it is necessary to go a step farther.
3. This step may be made by giving a brief glance at the squadron combat.
Approach.—The typical cases to be considered for the approach may be reduced to two; that is to say, that of the blockade and that of fleets with freedom of movement.
It is evident that the present development of torpedoes will oblige the battleships of a blockading fleet to make short their incursions into the tactical zone of the blockaded place; the blockading force should form a chain, of which the end nearest the port is formed of simple videttes (destroyers), and the outer end of battleships that keep together, cruising or possibly at a temporary base. The links of the chain are groups of vessels; the position and the composition of these groups must conform to two rules.
1. The greater the importance of the vessels the less are they to be exposed to the risks of torpedo attack.
2. Each group is to retire as slowly as possible toward the next outer one, which moves to its support, in such manner as not to lose contact with the main body of the enemy who is seeking to force the blockade, repelling the secondary forces of the enemy, that are seeking to gain freedom of action for their principal forces.
Reciprocally, the blockaded party, in order to force the blockade, will seek to drive as far off as possible the advanced groups of the enemy, so that its main body may come out unobserved. To accomplish this diversion there is required a group of swift, and at the same time, strong vessels; in short, it is easily understood that such action has the greater probability of success the greater is the force of armored cruisers. In order to render vain the attempts of the enemy in this direction and satisfy the other conditions previously stated, it is necessary, on the part of the blockaders, that the penultimate link of the chain that begins with the videttes and has its head in the main body, may be made up of armored cruisers. If the blockaders have at their disposal battleships of high speed, such as those of the type described in Chapter I, such ships can render efficient service, since they can, more quickly than others, support the armored cruisers and prevent the diversion attempted by the enemy; but it is very important to note that vessels of this class, if they constitute the most important units of the fleet, cannot be kept in advance of the main body without exposing them to risks that their importance makes it necessary to avoid. These vessels, then, may support the armored cruisers at need, but only up to a certain point, it being necessary for them to remain within the limits laid down for battleships.
Analogously it may be said in the case of squadrons that, besides the strategic scouting, having for its object to keep the enemy in sight, they perform tactical scouting, meaning by this term, the scouting about a main body of vessels with the object of spying out the enemy's movements and covering our own; it is only necessary to mention that the forces destined for tactical scouting, in order to satisfy the requirements of the case, should be able to fight the tactical and strategical scouts of the enemy, as well as to return in time to their group leaders and to the main body for partial and general tactical actions.
This requires that the tactical scouts be disposed in such fashion that those farthest from the main body may be those of minor intrinsic tactical value and greater speed.
This being said, it may be useful to introduce a description that, although it may seem fantastic at first sight, will serve to fix the ideas upon the manner in which we may imagine to ourselves that the encounter of two squadrons surrounded by tactical scouts may take place. A scout of the outer line has seen a suspected vessel; moves to recognize it and, by means of the wireless telegraph, informs the nearest friendly vessel which in turn transmits the news to the commander-in-chief. Also the suspected vessel has headed toward our scout so that the recognition is quickly made; the vessel sighted is a protected cruiser of the enemy, weaker than ours, and that consequently, at a distance of not less than 7000 meters, turns to run. The commander-in-chief does not consider this to be of sufficient importance to change the course of the main body. The chase of the two cruisers continues for some time, and ours gains upon the adversary, so that there is hope of making a good stroke. Even a few shots which do not hit the mark are exchanged by the two parties when other suspected ships are seen on the horizon, and very soon they are discovered to be enemies. It is now time for our cruiser to show her heels; it is well to state, however, that while our vessel was getting farther away from our naval force (following the chase) another vessel was moving in such position as to be able to maintain with her the chain for the transmission of news. When the new hostile vessels are signaled a division of our own protected cruisers is already concentrating in the direction of the enemy; we have again the preponderance of forces and again the enemy withdraws. The course of the main body is somewhat inclined in that direction and the appearance on the horizon of the additional vessels decides us to effect a reconnaissance, that is, to ascertain if the principal forces of the enemy are more in number than those sighted. To this end it is determined to send toward the enemy a force that will not be obliged to retreat except before his main body; in other words, the armored cruisers are sent this time and the battleships follow at a distance ready to support them. The appearance on the horizon of a new hostile division further confirms the idea that an important force is to be found in that direction, and indeed in the new division we soon recognize the enemy's armored cruisers. The inferiority of the enemy in vessels of this type is not slow in producing its effect; the adversary, in order not to be beaten in detail, must retreat and seek the protection of his battleships that are sighted soon after. The object of the reconnaissance is attained; our vessels take up a course parallel to that of the enemy, at his speed, and signal to the commander-in-chief the composition and formation of the hostile force; our admiral is now in condition to arrange his forces for attacking the enemy in the most opportune manner, or to reverse his course if he does not wish to accept battle.
What has thus far been set forth concerning the approach of two fleets shows us that we must abandon the idea of having a type of vessels that answers at the same time to the requirements of a battleship and of an armored cruiser. The requisites of the battleships must be determined, as has been done in this study, on the basis of securing the maximum return from the various elements of power; the characteristics of the armored cruiser must then fall below those of the battleship, utilizing a reduction of protection and of armament to secure speed. The characteristics of our battleship closely approach those of the latest English cruisers of the Invincible type; but the question is a relative one because the terms, armored vessel, and armored cruiser, are far from having an absolute signification; it may very well be said that the characteristics of the type of battleship best adapted to the needs of one nation, may approach those of the type of armored cruiser best adapted to some other nation.
However, it clearly follows that the battleship and the armored cruiser answer to different necessities, and that a nation may abstain from constructing vessels of the latter type only when its possible adversaries do the same.
Cruising Formation.—The extension of the explored zone that could be obtained by extending also the battleships in chain as well as the cruisers may seem opportune when our vessels possess a speed superior to that of similar enemies, so as to be able to effect a concentration in good time; it must be avoided, however, when one occupies a central position between hostile divisions, because the English maneuvers of 1906 have very well shown the dangers to be encountered in this way. Also if the enemy can come from one direction only, it is necessary to resort to such a system when there exists the possibility that the assembly of our battleships may be delayed owing to the configuration of the coast. As an elementary measure of prudence, the general principle may be established that the battleships should cruise together and that the armored cruisers should be easily able to assemble on them.
The cruising formation of the battleships should naturally be determined by the possibility of torpedo attack and of tactical contact with battleships.
The vessels, by day as well as by night, may trouble themselves less about torpedo attacks according as their speed is greater; the reasons are: 1. The difficulty of estimating the speed of a vessel, already mentioned. 2. With the said speed there increases for the torpedo-boats the difficulty of reaching a position for launching the torpedo; this, for a torpedo-boat, depends upon the time necessary for reaching this position, keeping as long as possible beyond the radius of action of the light artillery; a submersible that sights a ship may submerge herself and approach protected by her invisibility, but her inferiority in speed with respect to her target hinders her doing this over a portion of the horizon that is greater according as her inferiority is greater.
A first defense against torpedo-boats is constituted by the tactical scouts; moreover, it is necessary to add destroyers to these scouts, and it is also necessary that other torpedo-boats be kept in close proximity to the main body in a way which we will now specify. This with the following objects:
(a) To oppose the hostile destroyers and torpedo-boats that may attempt to approach the main body.
(b) To signal the submersibles in time so that the ships may maneuver accordingly. In fact, in order to attack, the submersibles should submerge themselves at a distance of from three to five miles from the target, steering to meet it, correcting the course by means of the periscope, finally to place herself with the bow in the proper direction and launch the torpedo. If a submersible is signaled at the aforesaid distance, in order that she may not be able to reach a launching position, it is sufficient that the ship alter her course by an angle of about 40° for a moderate speed for the vessel and the maximum speed for the submersible (speed of the ship 12 knots, of the submerged submersible 8 knots, of the torpedo 24 knots over a run of 1000 meters).
The rules for the employment of the torpedo-boats for the protectionof the main body of the force are then as follows:
By Night.—Remembering that the torpedo vessels that come up from astern are the least dangerous, it is necessary that the naval force be preceded and flanked by groups of torpedo vessels, at such distance from the main body that the ships may use their search-lights at need without fear of illuminating them. Each of these groups should cruise in compact formation in order to be ready to attack the enemy's ships that it may meet. The utilization of the greatest cruising speed may be obtained by making these groups run in zigzags with their sides conveniently inclined to the course of the main body. These torpedo vessels should signal the enemy's torpedo vessels and endeavor to repel them without approaching within the range of the light artillery of their own ships since all the ships should be able to fire against any torpedo-boats that may approach them.
By Day.—In order to exercise vigilance against submersibles it is necessary that the destroyers keeping watch ahead and on the flanks be distended in chain; it is desirable to have a chain at three miles and one at five.
For the cruising formation of the vessels composing the main body of the force:
By Night.—Remember that the maneuvering of the hostile torpedo vessels will be intended to execute the attack while remaining as little as possible exposed to fire; for this purpose every torpedo vessel will attack the first ship, and only when they deem her to be disabled will they launch against the next one. It is best, then, for the ships of the main body to cruise normally in line ahead (column of vessels) with the following advantages:
1. To torpedo vessels sighted ahead there is offered a smaller target and the vessels can fire ahead by drawing out of the line ahead and to the opportune side as fast as may be necessary.
2. With torpedo vessels sighted abeam the maximum defense can be utilized.
3. The (attacking) torpedo-boats are placed under the worst conditions for retiring after launching their torpedoes.
4. The formation is easily manageable for successive changes of direction, signaling the amount of change with the stern light.
When the number of the ships is considerable it is better to use the formation in columns, with such interval between the columns as will permit the free use in action of the light guns and the search-lights. (The search-lights will be used only when the presence of hostile torpedo vessels has already been signaled.)
By Day.—The most suitable formation is, as is well known, that of line ahead if there are few ships, and in columns abreast if the naval force is numerous. Being able to maneuver in time to prevent hostile torpedo-boats of any class from passing between the columns, and being obliged, for reasons already pointed out, to keep the main body of the force compact, the interval between the columns may be kept equal to the open order interval (between vessels?), thus obtaining sufficient freedom of movement for unforeseen cases. The vessels that compose each one of the columns should be selected according to the idea of homogeneity, this being an elementary tactical necessity. Thus far we have turned our attention to logistic requirements; let us now examine into the best way in which a naval force may arrive in sight of an enemy.
Initial Battle Formations and Maneuvers.—If our cruisers have repulsed those of the enemy and have come into contact with the enemy's main body, in such fashion as to be able to give information concerning his movements, we have the singular advantage of regulating our movements by those of the enemy without his being able to do the same. The complete attainment of such a desideratum would require that the cruisers and the main body be in constant radiotelegraphic communication. This ideal will not always be reached because the enemy will seek to disturb our communications; it will, therefore, be necessary that the main body and the divisions in contact with the enemy be connected by a chain of light vessels for the transmission of news by wireless or by ordinary signals. On the basis of the information transmitted to it, the main body prepares itself for battle, so as to arrive in sight of the enemy in advantageous formation and position.
The benefit of seeking, out of sight of the enemy, an advantageous position comes from the fact that the more the distance of sighting, or, better, the distance at which the enemy can take account of our formation, is greater than that at which firing may be commenced, the more it is possible that at least a part of the initial advantage may be preserved up to the firing distance; such benefit will be all the greater the more the firing distance increases, approximating to the distance at which exact account may be taken of the adversary's formation.
The fundamental conceptions that should jointly inspire the tactical maneuvers, as well at the beginning as during their development, are the following:
1. To bring into action the maximum number of guns.
2. To have an advantageous tactical position.
The types of advantageous position may be reduced to two,* that is to say, putting a part of the enemy's forces under conditions of not being able to fire, or such that their fire may be less effective because executed at a greater distance than ours. The first object is satisfied by the T positions, the second by positions equidistant from the nearest part of the enemy's line, as shown in Figs. 2 and 3, in which, for simplicity's sake, the arrangements are represented by simple lines.
* A tactical position should also be considered advantageous when it is the result of natural elements (direction of wind, and of the sun, visibility of our vessel). But it is easy to convince ourselves that these elements are of secondary importance compared with the two types of position above indicated.
Equidistant positions bring, at the fighting distances and with numerous forces, a slightly curvilinear arrangement. Let us remark, however, that seeking to take an advantageous tactical position out of sight of the enemy, owing to the great length of the radius, the arc of the circle is indistinguishable from a right line, and hence the types just mentioned amount to arranging one's forces on a line of bearing normal to the nearest part of the adversary's force.
This being established, the party that is not in condition to drive back the hostile cruisers and thus cover its own movements, will seek to arrange itself on a line of bearing as near as possible to that normal. For this purpose, from information obtained from one's own cruisers, that will at least have had a fleeting glimpse of the enemy's main body, from the position of the latter's cruisers, as well as from the configuration of the coast, it will be possible to establish approximately the direction in which the principal hostile forces are to be found. For this party, the proper direction for the line will be determined in some such way; the course will generally depend upon strategic exigencies.
For the other party we may distinguish two cases, according as he may or may not find himself on the prolongation of the enemy's line.
Let us remember that for every tactical maneuver there exists a fitting counter-maneuver sufficient to render it futile; but even a slight delay in making the necessary response to the enemy's movement may establish conditions of inferiority with rapid results.
Let us now consider two hostile assemblages, each of which is drawn up in the direction of the line joining them, or in a line that is slightly deflected from it. Of these two parties, the one that at a certain moment rapidly changes direction will succeed in crossing the T, if the enemy delays to arrange himself in parallel fashion. This delay, which means a smaller number of guns brought into action, may depend upon delay in arriving at a knowledge of the enemy's maneuver, upon inferior speed, upon having the means of offense scattered over a larger number of vessels, or, finally, upon a formation that does not permit the rapid execution of the movement that would be necessary.
In the first of the cases before mentioned the party A, when his forces in contact with the enemy signal to him that the enemy B is drawn up in the direction of the joining line AB, could himself also approach in like array, with great probability of advantage on his part, when his speed is superior to that of B, and when each single vessel, contrasted with the hostile units, has a greater number of guns of the maximum caliber, which are those most effective at the great distances at which the action is begun.
An assemblage of vessels of the type considered in Chapter I would have the advantage in approaching in this guise a hostile force composed of ships of the Radetzky and Danton types; it would, therefore, be more prudent for the latter to renounce keeping the enemy to the last uncertain as to the maneuver that he intends to make, assuming a formation normal to the joining line AB.
When the enemy's line departs considerably from the aforesaid joining line it will generally be best for the force A to maneuver so as to bring about the arrival in sight in a position as near, as possible to a direction of minimum offense of the hostile assemblage. This is satisfied by successive changes of direction in line ahead, successively altering the course so as to keep it normal to the line joining him with the enemy.
That fleet that on sighting the enemy recognizes that it has the advantage of position and of formation will seek to change the distance as rapidly as possible in order to arrive in like condition at the distance for opening fire, or it will run at maximum speed.
The other fleet will seek to gain time for executing the necessary conversion of the line, and when it recognizes that its initial position is too much inferior, it will execute such conversion while retiring, unless it is hindered from so doing by local conditions.
The Duel.—In order to follow the line laid down in the beginning of the chapter, let us suppose that a vessel of the proposed type finds itself about to fight against a ship of the Danton type.
Our ship, which we will designate by I, has considerable superiority in bow and stern fire, having six 305-mm. and four 152-mm. guns, against two 305-mm. and four 240-mm. guns. If I, at the maximum distance at which the firing may be considered effective, keeps N bearing directly astern and keeps the same speed, the opposing ship, unless it wishes to drop out of range, must fight with I bearing directly ahead, thus placing herself in a condition of inferiority. Our vessel, owing to its greater speed and armament, may then: 1st, decline tactical action; 2d, put the enemy to the alternative of not being able to fight or of being obliged to fight end on.
If, however, I desires to fight at any cost and executes the above-mentioned maneuver, then N, bearing from I in a sector of maximum offense, will be obliged to do the same; the duel will then be developed with the adversaries bearing from each other in the sectors of 45° forward and abaft the beam.
If the vessel N has good reason for declining to fight, and on this account brings I to bear directly astern, our vessel will be in a situation to impose action in a way very advantageous to her, because she could alternately bring the enemy to bear ahead, and in a sector of maximum offense, as we have already pointed out in Chapter I.
Rather than remain in this disadvantageous situation arising from her inferiority in speed and in end-on fire, it would be better for the vessel N resolutely to accept the battle by bringing I to bear in a broadside sector.
Let us then examine the general case of the two supposed adversaries fighting and firing with the maximum number of guns. It is easily seen that all the directions included in the sectors of maximum offense are alike, in so far as regards the probability of the vessel's being hit. Indeed, the 'doubt may arise that owing to the facilities for the observation of the lateral misses, a vessel may have a smaller probability (of being hit) by presenting the beam; but this doubt disappears if the question is studied in concrete fashion. Our vessel necessarily having about 150 meters length and 25 meters beam, the difference between the depth of the supposed thin horizontal target on a bearing of 45°, and that when presenting the beam, is less than 10 meters. (It is exactly 9.75 meters when the horizontal section of the vessel is considered as an ellipse); hence it is negligible, the more so that in practice the lateral misses, although easily observable, will not be completely eliminated, and at 45° there will be a smaller lateral probability that will compensate for the small increase in the depth of the target.
The conditions in regard to the probability of being hit being thus defined, it is clear that the bearing on which it is better to keep the enemy in order to reconcile the offensive and defensive requirements is 45° forward or abaft the beam, or slightly less.
In order to establish rules for tactical maneuvers it is necessary to examine the question of the fighting distance.
The convenience of keeping oneself inclined to the line of fire being in general admitted, we may not determine the most convenient distance on the basis of the perforations at an angle of impact of 90° ; we are not even able to find the solution in the difference that exists between the two adversaries in the total energy developed by the projectiles on striking, because it is clear that the dynams (dinamodi) corresponding to a gun of 152 mm., or of 240 mm., are not to be compared with those of one of 305 mm., otherwise we should end by admitting that a certain number of guns of 37 mm. might be equivalent to one of 305 mm.
As we have already had occasion to point out, the question to which we now address ourselves is put upon a practical plane by our proposing to seek out, not a determined and fixed value for the distance, but the limits between which it is well that the distance be included.
The rules which we are seeking should tell us only if it is better to fight at between 3000 and 5000 meters, or between 5000 and 7000 meters.
The elements to be considered are: The strategic situation, the differences in the percentage of effective hits, in the armament and in the protection.
It is evident that the more the action becomes decisive the injuries that we inflict upon the enemy increase, but our own injuries increase at the same time; it is then a question of determining whether the difference does or does not result to our advantage. The application of the Nelsonian principle of annihilation is not always permitted by the strategic position; it is not necessary to restrict the view to the field of battle, but rather to look beyond the victory of the moment to triumph in the war. When the radius of action of weapons was very limited, looking to a relative safety was synonymous with ineffectual battle, but in the present state of things the struggle at long range is not any more ineffectual if the battle is limited to it than if it contemplates a struggle at a lesser distance. The principle is thus established that the greater the importance of the conservation of forces in view of the strategic situation, the more profitable is the long range action. Naturally the just appreciation of the situation can only be made in the concrete case and not in a general study like this; we may remark, however, that when we are engaged in a struggle with a weaker navy, we shall have less interest than the enemy in the conservation of forces; but this would not signify the necessity, from the outset, of closing the distance.
The difference in the percentage of effective hits, the number and class of guns being equal, may depend upon various causes, as, for instance, a difference in the ability of the gun-pointers, in the efficiency of the mechanism for gun laying and for the measure of distances, etc. In a word, the difference evidently varies with the firing distance; it is dear that at short distances even a mediocre gun-layer fires very well, while the difference in ability is always more to be noted when the distance increases and is so much the more apparent if the vessel is subject to rolling and pitching motion.
Whoever at any moment keeps his own percentage of effective hits greater than that of the enemy should remember that such difference between percentages tends to increase, because it produces injuries and disorder.
The difference in armament may be considered from the point of view of the number and class of the weapons. With equality in class of weapons, the effect of a quantitative superiority is the more felt, the more the distance diminishes; the exponent of the advantage that the most numerous combatant obtains in diminishing the distance is evidently represented by the probability of hitting multiplied by the difference (in number) of the guns of the class considered.
But this diminution of distance has a limit depending upon the class of the weapon in which the advantage lies, and it may even be reduced to zero; such is exactly our case, because, while against a vessel armed with four heavy guns and a numerous battery of medium caliber, the rule just laid down would bring our type of vessel in the neighborhood of the lower limit of the long distance, on the other hand, with a ship of the Danton type, it must be said that, still, the 240-mm. guns are long range weapons, and that consequently for our type the maximum distance is advantageous, at least at the beginning of the action.
In regard to differences in protection we know that the maximum thickness of the armor in the Danton type is 25 cm., and, even if it were somewhat greater, the protection in our type of vessel would always be equivalent thereto by virtue of an opportune inclination (to the line of fire), with the advantage of a greater extent of protected surface.
On the whole we see that with our type of vessel it is better to keep the distance near the maximum; the progress of the action and the strategic situation may render it advisable to follow the initial phase with another at a shorter distance. The long range is better, even in the case that our vessel must, for fleeting instants, present her beam, because of the greater perforating power of the 305-mm. guns.
To illustrate, let us admit that our vessel determines to keep the distance between 5000 and 7000 meters; although there may not be established a fixed value for the distance, there exist reasons owing to which it is generally advisable to keep constant some value of the distance included between said limits.
Since the danger space diminishes as the distance increases, at long distances it becomes necessary to follow the distance very exactly with the sights, much more so than it would be necessary to do at medium distances; it is, therefore, indispensable to keep the distance nearly constant when one has more interest than the enemy in making this phase of the combat effective.
But if the enemy should present his broadside, our vessel should also do the same, if it is desired to keep the distance constant; it will hence be necessary for us to content ourselves with keeping it within the desired limits by bringing the enemy to bear alternately 45° forward of, and 45° abaft the beam. The decrease in the efficacy of the action on account of the variableness of the distance will be compensated for by the possibility of perforating the enemy's armor, while our vessel will only present the broadside at the instant of passing from the bearing forward of the beam to that abaft, and vice versa.
In substance the maneuvering of our vessel in the duel is the following:
We have a horizontal circle on which are marked the fields of fire of the guns, and about its center revolves an alidade for steering by the sight vane. It is established that the speed is not to be allowed to fall below a certain value, for example, 15 knots.
Let us suppose that the enemy has us bearing forward of the beam; we commence steering with the sight vane at the angle 45° abaft the beam, at maximum speed; if we perceive that the distance is increasing, we have the angle of the sight vane unchanged and lessen the speed little by little until we reach a value at which the distance remains constant; if at the speed of 15 knots the distance continues to increase, we bring the enemy to bear little by little toward the beam; arrived at a certain angle of the sight vane, 35° for example, it is well not to approach the beam further but to allow the distance to increase up to the highest limit established and then pass to the angle with the sight vane 45° forward of the beam, and so on. We maneuver analogously if the enemy has us bearing abaft the beam.
It is to be noted that our vessel (by virtue of her superior speed) would be mistress of the maneuver even if the sectors of maximum offense were extended to 51° from the beam in the Radetzky and to 55° on the Danton.
Battle between Homogeneous Groups.—The maneuvers pointed out for the fuel debar our vessel from seeking to pass the enemy on an opposite or parallel course; aside from everything else, it is sufficient for the exclusion of this maneuver to observe that at any one instant the bearings of the combatants from each other would be exactly the same, but from this the enemy's vessel would be able to draw the greater advantage, having plates more resistant than ours, owing to the fact that our ship had abandoned maneuvering on the bearing which permitted her to compensate for the greater vulnerability of her armor.
The same thing may be said of the case in which a group of vessels of the proposed type is engaged in a struggle with vessels of the foreign types considered. With the same formation, passing in opposite directions is more profitable for the ships that have the heaviest plating, and naturally it would best suit that party to facilitate our falling into that error, the more so that it is in our power to avoid it. If other conditions do not prevent, it forces the enemy to fight forward of the beam.
It is well to note, however, that passing in opposite directions with our ships in single column can be advantageous whenever the enemy keeps a formation other than that of single column, essentially because, with the continual change in the bearings, our vessels will be for some moments in the directions of minimum offense of the enemy as a whole; in so passing we shall naturally seek to form a T across the enemy's rear.
The simplest idea would be that of maneuvering our vessels in single column in succession, while the leading vessel would maneuver as in the duel with respect to the nearest vessel of the enemy; but it is easily understood that aside from the advantage of keeping the distance within the desired limits, such maneuvering would not generally represent the best utilization of the qualities of our vessels.
Nevertheless we remark, without need of recourse to a minute analysis, that maneuvering in column, in succession, that has the great value of facility of execution, is to be recommended when the enemy keeps unaltered the magnetic bearings between his own vessels, or keeps on a constant course for a considerable time. The single column then lends itself in the best way to the securing of positions for crossing the T, or of positions equidistant from the nearest part of the enemy's line.
Thus, for example, the maneuver for forming the T should evidently consist of the following two successive parts:
1. To bring ourselves in a direction of minimum offense of the enemy.
2. To place ourselves on a line of bearing normal to a line joining a part of our own formation with the nearest part of that of the enemy.
We may not overlook the offensive and defensive situation of the group in the first phase of the maneuver, and it is desirable that on arriving in the direction of the enemy's minimum offense, the group may find itself already formed on the normal line of bearing. To this, owing to its flexibility, the maneuver in succession in single column lends itself very well, and we may hold, therefore, that in the generality of cases it will be preferable to the other of moving on a line of bearing (bow and quarter line) and executing afterwards a rotation of the line.
For the equidistant positions, the already mentioned drawing of White of the battle of Tsushima, in the part regarding the movements during the first hour, illustrates the efficiency of the single column against an enemy that obstinately keeps to the same formation with a constant course. As that may be attributed to the very considerable difference of speed that existed between the adversaries, we have designed Fig. I of Plate III that refers to a hypothetical case in which 10 vessels of our type with a speed of 22 knots make against 10 hostile vessels moving at 20 knots, a maneuver analogous to that which, according to White, was made by the Japanese. The distance between ships is, for both parties, 300 meters.
The admiral of the speediest party, who has the head of the line, before arriving at the firing distance steers as if he wished to pass on an opposite course, and in such fashion that his own vessels are about at the same distance from the head of the enemy. Before entering the sector of maximum offense of the head of the hostile column (45°) he quickly changes direction followed by the other vessels, bringing the head of the enemy's column to bear 45° from the stern, and for a certain time he keeps that bearing constant. The tactical situation of the slower party continually becomes worse, so much so that after 20 minutes the head of our column may, without inconvenience, diminish the angle of the sight vane from the beam in order to dispose his vessels in positions about equidistant from the head of the enemy. If we consider the positions after 25 minutes of firing we find that the difference between the distances at which the swiftest vessels execute the firing (they all fire with the maximum number of guns, naturally concentrating their fire upon the head of the enemy's column) is 600 meters (5200-4600), while for the ships of the enemy (which concentrate their fire upon the rear of our line) the corresponding difference is 2100 meters (6700—4600), with the disadvantage of not firing in a sector of maximum offense.
If this leads to the admission that even an advantage of two knots' speed may be sufficient to give the advantages that Togo obtained at Tsushima, it is nevertheless not enough to authorize generalizations. The hypothesis that the enemy may maintain a passive attitude similar to that which we have just supposed is not to be excluded, because when the fire is concentrated on the ship that leads the enemy's line, we may hope that by putting the said ship out of action, the case of a line without a head will be repeated, as was the case in the battle of August 10 and at Tsushima, but that does not remove the possibility of a very particular hypothesis, and it is best to supply rules on the general hypothesis that the enemy may maneuver so as to utilize well all his forces.
With this object we observe that, since we are considering a combat between homogeneous groups, the hypothesis of a combat of 10 vessels of our type with 10 of the enemy's is an abstract one; of the said vessels we can put in construction four, while France is constructing six Dantons and Austria three Radetzkys. The vessels that we may afterwards construct will differ from these, and in their employment with existing ships they will enter the field as heterogeneous groups.
It is then practical to suppose that four vessels of the proposed type may be found fighting against four or six units of a comparable type.
The rules for the maneuvering of said group should be general like those for the duel, that is to say, not limited to a particular hypothesis. Let us bear in mind the objectives to which we must look, classifying them in the order of their importance:
1. All the vessels should be able to fire with the maximum number of guns at the enemy's vessel upon which it may be opportune to concentrate the fire.
2. Seek to occupy positions equidistant from the said enemy's vessel upon which fire is concentrated.
3. The utilization of the group will be greater the greater the tactical return of each unit, that is to say, the more the maneuvers of each and every vessel with respect to the enemy's vessel, on which the fire is concentrated, approximate to those of the duel, that is, convenient inclination (to the line of fire), and a distance constant or slowly variable.
The same rules laid down with respect to the duel concerning the most convenient distance can evidently be extended to the case of homogeneous groups, and they establish for our group the convenience of fighting at long range, and so bringing it about that the distance may be nearly constant; but precisely as in the duel we must not be fast bound to maintaining the distance constant at any cost, but allow it to vary, if necessary, between the most opportune limits. Thus, for example, supposing the two hostile groups in single column, the head of the column of the slower group, by keeping the head of column of the other group abeam, obliges him to present the beam in his turn if he wishes to keep the distance constant. The tracks of the two adversaries will in this way result in concentric circles; at short distances, the curvature of the trajectories would cause the rear vessels of the slower group to have their fire masked by those ahead of it, but this would not happen at long range. Under such conditions the swifter group would have no sensible advantage; it would then be well for it to give up the constant distance to obtain the advantage of a better inclination to the line of fire.
The objectives being established as aforesaid, the rules for maneuvering follow as a direct and logical sequence, taking count of the following axioms:
I. After having excluded the notion that maneuvering in single column can satisfy any case whatever, we ought not to bind ourselves to maneuvering on a line of bearing, to be changed from time to time. In fact it is true that for every tactical situation there exists a line of bearing that answers the purpose, but the time necessary for passing from one line to another is very considerable, even with a limited number of ships, so as to render it impossible to foresee the tactical situation at the end of the maneuver with sufficient exactness.
2. With a group composed of a limited number of vessels, such as we are now considering, the possibility of allowing each and every vessel a certain liberty of movement is understood, thus obtaining that the formation is continually changed, in the opportune way, by adapting itself at every instant to the movements of the enemy.
This being granted, the general rules that we are seeking are the following:
(a) The vessel that regulates the movements of the group will at all times maneuver with respect to the nearest enemy's vessel, or more generally, in respect to an extreme vessel of the enemy's formation (care must be taken to indicate this vessel to the other ships), as he would do in the duel, at a distance constant or variable according to the cases already considered.
(b) The regulating vessel of the group is tile inside one on the side of the changes of direction necessary for steering by sight-vane.
(c) Each of the other vessels of the group, besides following in the water of the regulating ship, should edge off parallel to it, regulating the speed so as to bring it about on the arc of a circle that passes through the regulating vessel and has for its center the enemy's vessel upon which the fire is being concentrated, or in the position nearest to that circle that permits of keeping the aforesaid enemy's vessel in a sector of maximum offense. A vessel can generally be considered in the best position when the angle between the line joining the next friendly vessel to the regulator and the line joining the said vessel with the enemy's vessel (the target) is about 90°.
It is well known that this produces no danger of collisions, because the courses of two adjoining vessels are either parallel or slightly divergent, the changes of direction are not simultaneous but successive at very short intervals, as rightly should be the case. With this maneuvering, the intervals between vessels of the same group will undergo alterations, but keeping it opportunely in mind in changing the direction, it will be possible to render the effects negligible; in practice the formation will not be exactly on the arc of a circle, but it will approximate to it sufficiently to produce a good tactical situation.
As an application, Plate IV may be considered. It is supposed that the enemy maneuvers in single column; his leader N1 has our ship I1 (which is the nearest) bearing 45° forward of the beam, because he judges that in that way the following vessels may also be in conditions to have I1 in a sector of maximum offense. The intervals between vessels are for both parties established at 300 meters. The ship I1 desires to fight at 6500 meters; it is supposed that he is fighting the starboard side the same as the enemy. According to the rules for the duel, the vessel I1 steers by sight-vane on the bearing 45° abaft the beam, slackens the speed until he finds that the distance remains constant, and as the sight-vane angles are equal the speed determined in this way by I1 is the same as that of the N ships, so that the ship I1 as well as the N ships, is moving on the same circle with a radius of 4600 meters. The ships I2, I3, I4, moving according to the rules laid down, that is to say, keeping the distance from N1at 6500 meters, ought to trace circumferences with radii greater than 4600 meters, and hence there is necessary for them a greater speed than that of the enemy and of the regulator I1. As the relations between the speeds should naturally be equal to those between the radii of the concentric circles the necessary speed of the ship I4, which is the outer vessel, is 22 knots if the speed of the N ships is 19.5 knots. Each one of the I ships in this way has N1 bearing in a direction that is practically 45° from the beam. The vessels following N1 have the vessel I1 bearing at angles from the beam considerably less than 45° (for N6 the angle is 35°).
The rear vessel of the N group is then 7150 meters or 7400 meters distant from I1, according as the vessels number four or six. The differences 650 meters and 900 meters in the firing distances of the N vessels give to the I party a sensible advantage.
The observation that naturally arises is that the N vessels may place themselves on a circumference with a radius of 6500 meters and a center at I1 and trace circumferences concentric with that of N1 at lower speed, keeping I1 bearing 45° from the beam. In this way the party N would be in a situation perfectly identical with that of the I party.
But it may be considered that in this way the regulating ship of the N party would be the outer one on the side of the changes of direction, at least until the arrival of the vessels N1, N2 . . . .N6 on the circumference with center at I1;hence the maneuver does not present the same guarantees of safety for the party N as for the speedier party.
In order to have the same guarantees the N ships should deploy outside of the circle of N1, which would necessitate a slacking of the speed of the regulating vessel; but clearly this maneuver would be absurd because during it the N vessels would mask each other.
Let us suppose that the main part of a naval force A maneuvers together against that of an adversary who divides his force into two groups B' and B". The force A succeeds in getting into the interval between B' and B"; if it has a speed superior to that of the slower of the enemy's groups, which we will suppose to be B", the B party will be in a very disadvantageous position if A steers against B'. Indeed under such conditions B' can either keep its distance or steer against A. In the first hypothesis the distance from A to B" will constantly increase; in the second the forces A and B' will pass each other on opposite courses, but B" will have no part in the action.
We have, then, a particular case in which, the interposition between the enemy's forces permits of fighting with a united force against a part of the enemy's force. An examination of this case brings us to conclude:
1. The maneuver of separating the enemy is one that may advantageously be attempted by a compact naval force maneuvering against an adversary divided into groups, when the compact force possesses a speed superior to that of the slower of the enemy's groups.
2. A necessary condition in order that a naval force may fight maneuvering in groups is that each group shall possess equal or superior speed to that of the united enemy.
Italy always having taken care to obtain in her battleships a speed sensibly superior (and in any case not inferior) to that of contemporary ships of other nations, it is presumable that a hostile squadron could be constrained to keep his principal forces united in the presence of our own which would be able to maneuver divided into convenient groups.
The study of the battle of squadrons does not enter into the limits of this work; in order to restrict ourselves to indicating the return that we may expect from a group of vessels of the proposed type, it is sufficient to observe that battleships of high speed (such as those of the Vittorio Emanuele type and as would be those of the proposed type) will command an advantage in speed that will be the difference, not between their speed and that of the most recent vessels, but between their speed and that of the enemy's slowest type.
Under such conditions the new vessels will have an advantage in speed that it is not rash to place at about six knots, and this advantage will permit them, maneuvering generally in single column, to place themselves in directions of minimum offense of the total force of the enemy.
In conclusion the type of vessel that in our poor weak way we have endeavored to set forth answers to the same fundamental conceptions from which has already resulted the Bettolo-Cuniberti plan of a vessel of 8000 tons, and that has produced the ships of the Vittorio Emanuele type, with the addition of the high importance to be attributed to guns of a greater caliber. A group of these ships, with their high speed, with their heavy guns, in virtue of a good preparation of the personnel, will permit us to bring into action, from the beginning of the battle, from the maximum distance, that intense and powerful fire that will produce the first turning of the scale. This type is based upon the golden Napoleonic maxim frappez fort et vite, that has been so well applied by the Japanese, and upon which there is to be formed a truly modern system of strategy and tactics.