“As between the Admiral class and the central-citadel ships of the Inflexible type there is a difference in this respect which has been much commented upon. When the ends of the citadel ships are filled with water, the armored wall of the citadel still remains several feet above water; whereas, in the Admiral class, the top of the belt under similar conditions is very near the water-level. All that need be said on this point is that, notwithstanding the greater height of the armored wall above water, the citadel ships have practically no greater guarantee of safety against capsizing by means of armor-protected stability than the Admiral class. In both classes the armored portions require the assistance of the unarmored to secure such a range and amount of stability as shall effectually guarantee their security when damaged in action. And, as has been stated above, this condition is true of all armor-clads with narrow armor-belts.
“One other objection to the shortened belts yet remains to be considered.
“It is urged that when the thin ends are broken through or damaged by shot or shell, jagged or protruding holes will be formed in the plating near the water-line, and then if the ships are driven at speed, the water will flow into the holes in large quantities, and produce serious changes of trim and loss of speed. In support of this contention, reference is made to the published reports of experiments made with the Inflexible’s model about eight years ago. It is impossible to discuss the matter fully, and I must therefore content myself with a statement of my opinion, formed after a careful personal observation of these model experiments. First, it cannot be shown from the experiments that the presence of a shallow belt of armor reaching two to three feet above the still-water line would make any sensible difference in the dangers arising from the circumstances described. Holes in the thin sides above this belt would admit water in large quantities on the belt-deck when the vessel was under way, and if it could flow along that deck changes of trim and other disagreeable consequences would result. Secondly, it is certain that the numerous bulkheads and partitions, coffer-dams, etc., built above the belt-deck level in the Admiral class for the very purpose of limiting the flow of entering water would greatly decrease any tendency to check the speed or change the trim. Whether the belt be short or long, it is evident that gaping holes low down in the light sides will make it prudent for a captain to slow down somewhat if he wishes to keep the water out as much as possible. But between such prudence and the danger of disaster there is a wide gulf.
“Summing up the foregoing statements, I desire to record my opinion, based upon complete personal knowledge of every detail in the calculations and designs for the Admiral class, that the disposition of the belt armor (in association with the protective decks and cellular sides, water-tight subdivision, etc., existing in the unarmored portions of the vessels situated above the protective decks) is such that the buoyancy, stability, trim, speed, and manœuvring capabilities are well guaranteed against extensive damage from shot and shell fire in action. And, further, that in these particulars the Admiral class are capable of meeting, at least on equal terms, their contemporary ships in the French navy.
“I must add that I am not here instituting any comparison between the ‘fighting efficiencies’ of the ships of the two fleets; nor have I space in this letter to do so. Opinions have differed, and will probably always differ, as to the relative importance of the different qualities which go to make up fighting efficiency. There is no simple formula admitting of general application which enables the comparative fighting values of war-ships to be appraised. As the conditions of naval warfare change and war material is developed, so the balance of qualities in ship-designing has to be readjusted, and estimates of the fighting powers of existing ships have to be revised. And, further, different designers, working simultaneously, distribute the displacement, which is their sum total of capital to work upon, according to their own judgments of what is wisest and best for the particular conditions which the ships built from those designs have to fulfil. The designer who has the larger displacement to work upon has the better opportunity of producing a more powerful ship; but it by no means follows that he will secure so good a combination of qualities as a rival obtains on a smaller displacement. And hence I cannot but dissent from the doctrine that displacement tonnage is to be accepted as a fair measure of relative fighting efficiency, or that recent English ships are necessarily unable to fight recent French ships because they are of smaller displacement.
“In the preceding remarks I have been careful to confine myself chiefly to the naval architect’s side of the subject, as it would clearly be out of place for me to say much respecting the artillerist’s side. But, having had the great advantage of knowing the views of some of the most experienced gun-makers and gunnery officers, and having studied carefully what has been written on the subject, I would venture to say a few words.
“First, there seems, as was previously remarked, every reason for doubting, in the actual conditions of naval gunnery, whether it would be possible, not merely in a few minutes, but in a considerable time, to produce the wholesale destruction of the unarmored parts of modern war-ships which has been assumed in the condemnation of the Admiral class. If the Collingwood, or one of her successors, were simply treated as a moving target in a sea-way for the Amiral Duperré or one of her consorts, this would be a most improbable result. But, remembering that the Collingwood would herself be delivering heavy blows in return for those received, the chances of her disablement would necessarily be decreased. Secondly, it does not seem at all evident that the introduction of rapid-fire guns has such an important influence on the question of shortened belts as some writers have supposed. So far as machine guns are concerned, I well remember at the board meeting which decided to approve the building of the Collingwood the possible effects of machine-gun fire were discussed at some length, both in reference to the adoption of the barbette system and to the system of hull protection. The rapid-firing gun which has since been introduced is now a formidable weapon; but it may be questioned whether its effects upon the unarmored portions of modern war-ships would be so serious as those resulting from the shell-fire of heavier guns, and therefore it cannot with certainty be concluded that it would be advantageous to make arrangements for keeping out the projectiles from the rapid-firing guns now in use at the ends of the Admiral class. More especially is this true when it is considered that already rapid-fire guns of much larger calibre and greater power than the 6-pounder and 9-pounder are being made. To these guns three inches of steel would be practically no better defence than the existing thin sides, and the real defence lies in the strong protective deck. Shell-fire from heavier guns will probably be found the best form of attack against the unarmored or lightly armored portions of battle-ships, especially now that the use of steel shells with thin walls and large bursting charges is being so rapidly developed.
“I would again say that on this side of the subject I do not profess to speak with authority, and it is undoubted that great differences of opinion prevail; but it must not be forgotten that the Board of Admiralty, by its recent decision announced in the House of Commons, has reaffirmed the opinion that from the artillerist’s point of view the existing disposition of the armor in the Admiral class is satisfactory. This has been done after the attention of the Board and the public has been most strongly directed to the supposed dangers incidental to the rapid destruction of the light superstructures lying above the under-water decks of the Admiral class. It would be folly to suppose that in such a matter any merely personal considerations would prevent the Board from authorizing a change which was proved to be necessary or advantageous. With respect to the possibility of making experiments which should determine the points at issue, I would only say that considerable difficulties must necessarily arise in endeavoring to represent the conditions of an actual fight; but in view of the diametrically opposite views which have been expressed as to the effect of gun-fire upon cellular structures, it would certainly be advantageous if some scheme of the kind could be arranged.
“There still remains to be considered the question of the uses of armor in future war-ships. This letter has already extended to too great a length to permit of any attempt at a full discussion. It will be admitted by all who are interested in the questions of naval design that an inquiry into the matter is urgently needed, even if it leads only to a temporary solution of the problem, in view of the present means of offence and defence.
“Armor, by which term I understand not merely vertical armor, but oblique or horizontal armor, is regarded in different ways by different authorities. For example, I understand Sir Edward Reed to maintain that side-armor should be fitted in the form of a water-line belt, extending over a very considerable portion of the length, and that such armor, in association with a strong protective deck, and armored erections for gun-stations, etc., should secure the buoyancy, trim, and stability of the vessel. At the other extreme we have the view expressed in the design of the grand Italian vessels of the Italia class. In them the hull-armor is only used for the purpose of assisting the cellular hull subdivisions in protecting buoyancy, stability, and trim, taking the form of a thick protective deck, which is wholly under water, and above which comes a minutely subdivided region, which Signor Brin and his colleagues consider sufficient defence against gun-fire.