Engineering Wonders of the World
Volume I

390 ENGINEERING WONDERS OF THE WORLD. four are mounted in pairs on the broadside. Thus eight 12-inch guns—80 per cent, of the main armament—can be fired on either broad- side, and four, or possibly six, 12-inch guns— or 60 per cent, of the main armament—can be fired simultaneously ahead or astern. In adopting this arrangement, her designer (Sir Philip Watts) had in view that, while broad- side fire is held to be the most important in a battleship, all-round fire is also of great importance, since it lies in the power of an enemy to force an opponent, who is anxious to engage, to fight an end-on action. In view of the terrible potentialities of modern torpedo craft, and especially considering the chances of torpedo attack towards the end of an action, the numerous anti-torpedo-boat guns are separated as far as possible from each other, so that the whole of them could not be disabled by one or two heavy shells. Some indication of the havoc likely to be wrought in any future naval battle by the great 12-inch What a 12-inch Gun can do. guns of our latest battleships may be gathered from ex- periments carried out early in 1908 with a Hadfield 12- inch “ Heclon ” capped armour-piercing shell, fired with a velocity of 1,986 feet per second at a 12-inch Krupp- cemented plate. Not only did it perforate the plate, but it passed through three feet of oak backing, and after indenting two heavy steel plates in the butt the shell was recovered undamaged. The Dreadnought? s main armour belt has a maximum thickness of 11 inches, tapering to 6 inches at the forward and 4 inches at the after extremity of the vessel; the redoubt armour varies in thickness from 11 inches to 8 inches ; the turrets and fore are 11 inches thick, and the been given destruction the main transverse bulkheads below the main deck—which is 9 feet above the water- line—are without doors, and are unpierced except for the purpose of leading pipes or wires conveying power. The inconvenience in passing from one part of the ship to another caused by the absence of doors is partly overcome by the provision of lifts and other special arrangements to give access to the various compartments. Coming to the question of speed, a battle- ship must be well-balanced—that is, efficient armour and armament must not be sacrificed in order to obtain high speed, for, after all, she is intended *Speed °1 ... . , X1 Battleships. primarily to remain where the fight is thickest, and not to show a clean pair of heels. On the other hand, high speed and great fuel endurance give a better chance of obtaining a strategic advantage over an enemy, and better opportunity on going into action for choosing a range of fire that will suit the guns carried. These were the considerations which resulted in the decision to make the Dreadnought capable of steaming 21 knots, an unprecedented speed for a battleship. Turbine machinery, instead of piston engines, was adopted for the Dreadnought on account of the saving in weight and in the number of working parts ; reduced lia- bility to breakdown ; dimin- ished coal consumption at high powers, and hence extra boiler- room space ; saving in engine- room complement; and increased protection, due to the engines being placed lower in the ship. The cost to the nation of the formidable fighting machine which the Dreadnought undoubtedly is, was about £1,813,000. With increased size and augmented defensive powers, the cost of war vessels of all to safeguarding the ship from by under-water explosion. All Reasons for Fitting Turbine Machinery. The “ Dread = nought’s ” Armour. conning tower after conning tower is 8 inches thick. The protective deck varies from 1| inches to 2| inches in thickness. Special attention has Cost of Warships. offensive and