500

MODERN STEAM PRACTICE,

SCREW STEAMSHIP “ SERVIA.” Gross Tonnage 7400, nett 3900 tons.

(See Plate.)

The Engines are of the three-cylinder compound direct-actingarrangement; one high-pressure cylinder of 72 inches diameterand two low-pressure cylinders of 100 inches diameter each, and78-inch stroke of piston; the valves for high pressure are pistonvalves, and those for low pressure slide valves, with four ports, asshown on plans. The surface condensers (two) are placed fore andaft, forming part of support for the cylinders; they can be workedtogether or separately; the circulation of water is effected by twoof J. & H. Gwynne’s 20-inch Invincible pumps; the air and feedpumps are worked off lever on low-pressure engines. The crankshaft is in three pieces, of Vicker’s Steel, and is 25 inches diameter.The propeller is 24 feet diameter, and the boss and blades are ofVicker’s Steel. The starting gear is Browns patent steam andhydraulic gear.

Steam is supplied to the engines by seven Boilers , six of thesedouble-ended, with six furnaces in each, and one single-ended withthree furnaces, in all thirty-nine furnaces, of 4 feet 2 inches dia-meter and 6 feet 9 inches long; the total effective grate surface being1050 square feet, and the total heating surface 27,000 square feet.The boilers are of oval form, 14 feet 10 inches wide, 18 feet high,and 18 feet 3 inches long.

The engines on trial developed 10,500 I. H. P., and the speed atsea 17% knots per hour. The dimensions of the ship are: Lengthover all, 530 ft.; breadth, 52 ft.; depth from top of keel to top ofupper deck beams, 42 ft. The Servia crosses the Atlantic in littleover seven days, consuming 1300 tons of coal on the passage.

SCREW STEAMSHIP “ ITATA.” Tonnage 2391 b.m.

See Figs. 374 and 375, pages 498, 499.

The Engines, of 340 nominal horse-power, have one high-pressurecylinder 3 ft. 10 in. diameter, and one low-pressure cylinder 7 ft. 2 in.diameter; length of stroke 3 ft. 6 in. Number of tubes in surfacecondenser 1164, diameter 1 inch. Diameter of circulating pump1 ft. 8 in., stroke 1 ft. 9 in. Diameter of air pump 2 ft. 8 in., stroke