Engineering Wonders of the World
Volume I

THE ARMOUR OF A BATTLESHIP. 403 went through the armour without any trouble. A “ Heclon ” capped shell, made by Messrs. Hadfield, fired at Shoeburyness on January 3, 1908, perforated a 12-inch K.C. plate, 3 feet of oak backing in three thicknesses, a row of sacks filled with cement, 24 feet of sand, dented two steel floor plates of the butt, and was, nevertheless, eventually recovered undamaged except for the loss of its cap. This showed, amongst other things, the enormous amount of energy remaining in the projectile after per- forating a plate. Of course, the results on the trial ground are not likely ever to obtain at sea. In tests the plate is but a short distance from the gun, the range is constant, both firing-platform and target are stationary and fixed, the plate is shored up behind, and is at absolute right angles to the line of fire—in fact, everything is in favour of the gun. At sea the target will be moving horizontally, and, if the vessel be rolling at all, vertically also. Moreover, the plates are curved to the tumble-home of the ship’s side, therefore the projectile will strike a rounded surface. Finally, everything suggests that the gun will, at sea, fire at plates facing it more or less obliquely. So superior to armour did the shell prove, however, that many experts believe that the highly-efficient armour-pierc- ing projectiles of the present time, fur- nished with caps, have largely robbed Krupp cemented armour of its protective qualities. It is considered, indeed, that a reaction must set in shortly in favour of armour having ex- ceeding toughness rather than mere surface hardness. A new steel, known as “ Era ” steel, recently brought out by Messrs. Hadfield, enters largely into the protection of all our latest armoured ships, from the Lord Nelson class onwards. Last year this firm produced a plate which they called the “ cap-deflecting plate.” Its outer surface is “ waved ” or indented, giving it the appearance of corrugated iron. Under certain conditions, the particular form of the surface of this improved “ Era ” armour causes the cap to be displaced or deflected before it has time to give the necessary sup- port to the projectile, as occurs when ordinary flat-surfaced armour is attacked. Suggestions have recently been made by Signor D’Adda to armour warships with con- crete. That this material will be used in place of steel, at least not for a very long time to come, cannot be believed, yet the suggestion is worthy of note. Could a composition, effi- cient, durable, and impenetrable, be discovered, the building and equipping of warships would be simplified and accelerated, and much of the present expense, due to the tedious treatment of modern steel armour, would certainly be saved. DIAGRAMS TO SHOW THE ARRANGEMENT OF A BATTLESHIP’S ARMOURED DECKS.