20 APRIL 1912, Page 8

PRINCIPLES OF NAVAL DESIGN.

[COMMUNICATED.]

T"paper on this subject read recently before the Institution of Naval' Architects by Admiral Sir Reginald Custance has an interest not merely for men engaged in designing warships but for all who desire the well-being and full efficiency of the Royal Navy. For many years the author has been known as a diligent student of, and able writer on, naval history who has endeavoured to deduce from past experience principles which shall furnish guidance for the future. In recent years his lectures to officers passing through the Naval War College have been of great value, and it may be hoped that they will eventually be made available for a wider circle and in a permanent form. Sir Reginald Custance is an officer of large experience in responsible posi- tions afloat as well as ashore, so that his analysis of the determining influences which have led to victory in the naval actions of the past is not Merely that which a non-professional student might producer but is the work of a man who has commanded modern warships and fleets, and is familiar with the use of the latest types of weapons of offence and means of defence. In addition, Sir Reginald Custance brings to his task impartiality and industry, both of which qualities are essential to success in the laborious and difficult task of unravelling tangled narratives, the writers of which are always, or in nearly all cases, necessarily influenced by national or personal considerations. No two stories of the same action written by men who fought on opposite sides, or were in sympathy with one side, can possibly be in agreement ; and the student has to find his way and form a judgment as best he can through these coloured statements in his attempt to discover the truth. Admiral: Custance has a rare faculty for work of this kind : he has the power of stating reasons and conclusions in a simple form and in non-technical language. These qualities add immensely to the value of his work for general readers. Starting with the principle that the gun is still, as it has always been, the predominant weapon in modern naval war- fare, and that ramming is now abandoned as a, means of offence, while the automobile torpedo—important as it may be—is subordinate to the gun, Admiral Custance shows con- clusively that victory has always been on the side of that combatant who could make the greatestnumber of effective hits in a given time, beat down his enemy's fire, destroy the mobility or manoeuvring power of the ships attacked, or demoralize the crews and compel surrender, In the circumstances of a sea-fight, when ships engaged are moving rapidly and as a rule rolling more or less, the percentage of effective hits to the total number of rounds fired is comparatively small even with highly skilled gunners. Examples of this fact are given, and from it is deduced the general principle that success is likely to i depend n future, as it has done in the past, upon the adoption of armaments which include a considerable number of guns of moderate individual power, rather than upon the use of a much less number of heavy guns as has been the practice since the advent of the Dread-, nought. Admiral Custance keeps his own opinions very much in the background, but all the same drives home the point just stated in a manner that is not easily resisted.

As to the range at which future naval actions should be fought he makes statements of great interest and practical importance, showing that victory has usually fallen to the commander who has pressed home his attack and conic to a " decisive range." It is the fashion for advocates of the " single-calibre big gun " armaments adopted for Dread- noughts to insist upon the view that " long-bowls " con- stitute the proper mode of attack. Because fair practice can be made in peace time at ranges of six or seven miles these writers picture the destruction of an enemy by the fire of heavy guns—which are more accurate than lighter guns at such long ranges—although the enemy can only be soon by the officers in fire-control stations and by making use of powerful telescopes. This conception has been the basis on which the abandonment of secondary armaments of 6-inch quick-firing guns has been justified hitherto : these guns are said to be ineffective and inaccurate at extremely long range. Other navies have not followed our lead in this respect, and Admiral Custance gives good reasons for retaining secondary armaments. He points out the fact that if fighting is really intended, and running away is not to be the main idea, then the choice of range is not in the hands of either combatant, but is determined by their relative movements, each having an initiative. He shows that the decisive range is likely to be much less, even under existing conditions, than is assumed by the advocates of very heavy guns ; and by inference he differs from the conclusion that recent increases of calibre from 11 and 12 inches to 13.5 or 14 inches have been an improvement in armament.

As to the torpedo, Admiral Custance said little, and it may be assumed that his advocacy of coming in to a decisive range for the guns did not overlook the enormous developments which have taken place of late in the effective range and average speeds of automobile tor- pedoes. Other speakers spoke of ranges of 8,000 to 10,000 yards for torpedoes, and dwelt upon the risks involved when ships drew closer than that range to one another. Obviously such risks must be run, but all past history shows that the men who have the courage to face risks and odds in order to press home their attacks have generally been the victors. Admiral Custance thinks the principle still applies, and his conclusion seems reasonable. " Long bowls" and the use of a few very heavy guns may impress the minds of men seated in offices or imbued with ideas based on gun practice in peace time and under exception- ally favourable conditions of sea and weather. But in actual warfare other conditions will prevail, and if the struggle comes in the North Sea there is little prospect of clear weather or the possibility of making effective hits at excessively long ranges. Nor is it necessary in order to put a modern warship out of action to perforate her thickest armour or drive into her interior single heavy shells with enormous explosive force in their bursting charges. It is customary to dwell on the last-mentioned form of attack and to declare its results to be fatal to even the largest ships, but experience and experiment hardly bear out these sweeping assertions, " Volume of fire "—that is to say, a great number of effective blows from projectiles of less size and power—is, on the whole, more likely to secure victory than the more impressive but less numerous impacts and explosions of projectiles from a few heavy guns. Some heavy guns are undoubtedly of value. What is questioned is the adoption of heavy guns alone.

In connexion with armour Admiral Custance is not as clear or convincing in his argument as he is in regard to guns ; but his remarks are valuable and suggestive. Obviously he is a believer in the principle that " an active offence is the best means of defence," and if he can keep down the fire of an enemy he considers a moderate amount of armour defence to be sufficient. The principle is sound enough ; its practical application is the difficulty, and in this department further thought and discussion are required-. The paper under review will serve as a most useful point of departure for that discussion. In strong contrast with its general drift is thep oliey adopted in the latest battleships of the United States Navy, on the sides and batteries of which it is said that a greater weight and thickness of armour will be fitted than has been used on any preceding vessel. Admiral Custance dealt also with the actual value of high speed in battleships, with the movements of fleets in action, with the relative values of broadside and end- on fire, and other important features influencing war- ship design. On all the points touched his thoughtful and impartial treatment threw strong light. On the whole his paper showed the path on which real advance must be made, if made at all. It has been too much the fashion for .naval officers to concentrate attention on individual features of design ; to deal with certain requirements independently rather than with the tout ensemble of a warship considered as a fighting machine ; and to be so engrossed in their particular view as to fail to see the force of views expressed by others. The differences between naval officers on really vital points have been notorious, and the reason for these differences is readily understood, If the saner treatment of these important subjects which Admiral Custance has followed could be made the rule in future, there might be anticipated a better, broader, and more continuous practice in the development of warship design under the varying and complex condi- tions inevitable in this ago of mechanical invention and scientific improvement.