Page:Popular Science Monthly Volume 44.djvu/187

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Great care has been given the water-tight subdivision, both above and below the armor belt, in order to prevent a catastrophe such as that which befell the Victoria; especially above the armor belt, where the subdivision of that unfortunate vessel was very weak, has the Iowa received most careful attention. The machinery is capable of developing 11,000 horse power, and will propel the vessel at a speed of seventeen knots per hour; the engines are of the triple-expansion type, being inverted, direct acting, and surface-condensing, driving twin screws. The coal supply is sufficient when steaming at ten knots to admit of crossing the Atlantic and back without recoaling. The United States steamship New York (Fig. 5), which lately created so much enthusiasm on account of her remarkable development of speed, is of the armored-cruiser type; but the Brooklyn, now being built under contract, is a very distinct advance upon the general design of the New York, and will here be taken as the exponent of her type. We find her to be provided with sufficient power to drive her at the rate of twenty-one knots or twenty-four miles per hour, and to have a coal supply of 1,800 tons, which will give her a very large radius of action. The main battery carried is eight 8-inch and twelve 5-inch breech-loading rifles; the 8-inch guns are mounted in pairs in turrets, protected by steel armor seven and a half and five inches in thickness; the 5-inch guns and the battery of machine guns, eighteen in number, are protected by steel armor varying in thickness from four to two inches. The protection to the hull, machinery, and magazines is afforded by a steel deck of a maximum thickness of six inches, being five feet below the load line at its outboard edges, and sloping upward and inward to the height of the load line on the flat portions, as shown in Fig. G.

Beneath this deck are placed engines, boilers, magazines, steering gear, and electrical generating plant, in fact all such parts as would be injured by and disable the vessel if exposed to the enemy's fire. To protect the stability an armored belt four inches in thickness is worked from the sloping armor to four feet above the load line for the space occupied by the engines and boilers, the object being to provide resistance sufficient to cause high-explosive shells to explode before entering the sides of the vessel. Inside of this and extending the whole length of the vessel is a coffer dam of obturating material, as shown in the outline midship section. Fig. 6, and the spaces both above and below the armor deck are closely subdivided by longitudinal and athwartship bulkheads into many compartments in which coal and stores are stowed, thus as far as possible, with the means now at the command of the naval architect, precluding the sinking of the vessel when injured.