SCIENTIFIC NEWS. 



[March ist, 1887. 



THE SCIENCE OF WAR-SHIP DESIGN. 



TN the course of a lecture on this subject, recently 

 ■'■ delivered by IVIr. W. H. White, the able Director of 

 Naval Construction, some interesting particulars were 

 given, illustrating the mighty forces brought into play 

 when the monster guns, carried by our most powerful 

 armour-clad vessels, are fired ; and the admirable manner 

 in which such forces are held in subjection by the me- 

 chanical appliances of the present day. The modern 

 artillerist is fond of speaking of ships as " gun-carriages." 

 This is doubtless a truth, but not all the truth ; for though 

 the gun yet remains the principal weapon, the ram and 

 torpedo will be hkely to play an important part in future 

 naval engagements. The battle between guns and armour 

 has been going on ever since ournaval constructors followed 

 the example of their French confreres, and first placed 

 armour-plates on the sides of war-ships. The contest is 

 often spoken of as a duel, but it is one that is not altogether 

 fought on equal terms. The artillerist has gone on increas- 

 ing the size of his guns, adding weight on weight, both to 

 the weapons themselves and to the charges with which they 

 are loaded ; not altogether with unvarying success, as 

 recent mishaps have only too conclusively proved. The 

 naval constructor has had to submit to the conditions thus 

 imposed on him, and has so made possible the exercise of 

 forces which are antagonistic to the success of his side of 

 the question. The public would do well, therefore, when 

 an unusually heavy projectile pierces an exceptionally thick 

 armour-plate, to award the naval architect his due mead of 

 praise for making the carrying of such a gun a possibility. 

 "Every increase in the weight and power of guns," said 

 Mr. White, " adds to the difficulty of the ship-builder ; for, 

 in the final result, every strain incidental to carrying and 

 fighting the guns, has to be borne by the structure of the 

 ship." The Renown, one of our largest armour-clad vessels 

 now in progress, has a single turret, in which will be placed 

 two iio-ton breech-loading guns, the largest and most 

 powerful ordnance yet mounted in any of her Majesty's 

 ships. The total moving weight of the turret, guns, etc., 

 exceeds S50 tons. " This enormous weight is concentrated 

 on a circle 36 feet in diameter, and has to be rigidly sup- 

 ported. Around the turret base, and protecting the loading 

 appliances, is an armoured redoubt, weighing close on 800 

 tons, and extending over a length of 60 feet. This also 

 has to be rigidly supported. When these two guns are 

 fired together, the mechanical energy stored up in both 

 projectiles exceeds 120,000 foot tons, an amount of ' work ' 

 equivalent to lifting the whole vessel through a height of 

 12 feet." We do not suppose the Director of Naval Con- 

 struction intended to say that he has to provide, in the 

 structure of the ship, for an equivalent to lifting her 12 feet 

 out of water ; for the energy stored up in the projectiles, and 

 that due to the recoil, are not brought to bear in the same 

 manner, the speed of the projectile being so far greater than 

 that of the movement of the gun. Still it is only by the 

 most skilful disposition of materials that sufficientstrength can 

 be obtained to resist these enormous strains, without in- 

 creasing the displacement beyond practicable limits. 



It is well known that Italy possesses the largest, and 

 many competent authorities seem inclined to say the most 

 powerful, war-ships afloat. The Italia and her four 

 sister ships have, or will have when completed, a 

 displacement of 13,251 tons. They are to steam eighteen 

 knots an hour, a speed which it is estimated will require the 

 expenditure of eighteen to nineteen thousand horse power. 

 The total weight of barbette, guns, and mountings, carried 

 at a height of thirty feet above water, closely approaches 

 the total weight of the first-class line-of-battle ship of the 



eighteenth century. Our own Nile and Trafalgar, which 

 are being hurried forward to completion with all speed at 

 Portsmouth and Pembroke, will displace 11,940 tons, and 

 they will, it is estimated, steam at their fastest sixteen and a 

 half knots an hour, necessitating an expenditure of twelve 

 thousand horse power. These two noble vessels when 

 completed will be the most powerful ships in the Royal 

 Navy ; yet, so far, it would seem they do not compare very 

 favourably with the Italian ships : but there is more still to 

 be said on the side of the latter vessels. The Nile and 

 Trafalgar -wWl both carry four 67-ton breech-loading guns, to 

 serve as their chief weapons of offence, whilst the Italia and 

 her consorts will each be armed with four iio-ton breech- 

 loaders. We therefore see that the Italian ships far outstrip 

 our own in size, speed, and weight of armament ; but it is 

 needless to say there is something to set off against all this 

 The Nile and Trafalgar will each have in addition to the 

 armour on the citadel and turrets, and an armoured deck, a 

 belt of steel faced armour on the water line with a maximum 

 thickness ot twenty inches. The Italian ships are, on the 

 other hand, entirely without armour on their sides, but the 

 vital parts of these vessels are protected by massive plates 

 wrought inside the vessel. We therefore see that whilst 

 the English ships have twenty inches of steel-faced armour 

 on the water line to keep out the projectiles of the iio-ton 

 Italian guns, the sides of the Italian ships would offer free 

 and unrestricted passage to the projectiles of the English 67- 

 ton guns. The great question of the day is, which of these 

 two is the best system ? Both sides have able advocates, 

 and it may safely be said that the problem will never 

 definitely be solved until the " rough arbitrament of war " 

 brings the matter to a practical issue. We may joyfully 

 say that Italy and England have too many bonds of sympathy 

 and affection for it ever to be likely that their fleets will 

 engage in more than friendly rivalry. 



A modern war-ship, as has been often pointed out of late, 

 is a compromise. The extension of one element of defence 

 or attack can only be obtained at the expense of others. 

 Thus, an^ndue weight of armour necessitates smaller guns, 

 lighter propelling machinery, and consequently slower speed, 

 or the lack of som.e other desirable feature. But after all, 

 the great governing principle on which all others are based 

 is that of cost. The British taxpayer will only submit to be 

 mulcted a certain sum annually, and it must be remembered 

 that war-ships are not only expensive to build but costly to 

 keep up. The question therefore is, which is the best way 

 to spend the money ? Some critics of our policy of construc- 

 tion say we ought to put side armour on our ships from 

 stem to stern. " Very good," say the Admiralty construc- 

 tors, " but if so, we must make the ships bigger and more 

 costly, and therefore there must be fewer ships, or more 

 money must be forthcoming." The iV//« and Trafalgar \w\\\ 

 cost close on a million apiece, and the money spent on their 

 armour alone would purchase a couple of armoured cruisers 

 complete, with armament on board ready for battle. It is 

 said that a design of a war-ship, prepared at the Admiraltj"-, 

 to embrace all the more important conditions demanded by 

 various critics, showed an estimated cost of ;^i,8oo,ooo ! 



It is perhaps an open secret that some of the professional 

 officers at Whitehall consider the abandonment of side 

 armour, at any rate, within the range of " practical politics " 

 in the near future; or at least such was the feeling a 

 very short time ago. Sir Nathaniel Barnaby, the recently 

 retired chief of naval construction, has openly expressed his 

 admiration for the Italian ships and his disapproval of the 

 Nile and Trafalgar. As a matter of fact, the area protected 

 by outside armour has, in British war-ships, grown less and 

 less of late years, until a check was given to this tendency 

 in the two last-named vessels, when we made what is con- 



