The Works Of Messrs. Schneider And Co.

MARINE ENGINE CONSTRUCTION. 105 (See Figs. 270 to 275, Plate LV.) The engines are of 1,500 horse-power, and each boat lias two Du Temple boilers, as prescribed by the French Navy Department. The engines are vertical, with three cylinders and triple- expansion, provided with a tubular surface condenser, the air and feed pumps being worked direct from the main engines. The following are some dimensions : ni. in. Diameter of high-pressure cylinder .425 16! 1 ,, mean-pressure ,, .610 24 ,, low-pressure „ .870 34J Stroke .450 17H Revolutions ... 3(50 360 cylinders are supportée! are of forged steel. All the crank- shafts, intermediate, and propeller, skafts are hollow, and of forged steel ; the propellers are of special bronze, with blades fitted on. Each engine-room is provided with two ventilators, one for delivering fresh air in the engine-room, and one for exhausting the hot air. The Condensed water delivered by the air pumps of each engine is collected in a tank provided with filters, whence it is delivered again into the boilers. Special evaporators serve for producing fresh water to make good loss. There are 24 boilers of the Lagrafel and d’Allest type, as prescribed by the French Admiralty for this battleship, placed in four stokeholds the boilers are conneeted with two funnels. When the torpedo-boat is under steam, circulation in the condenser is produced naturally by running ahead. When the boat remains stationary, the circulation is effected by means of a small centrifugal pump. A filter is fitted to the discharge of the air pump, in order to cleanse the water, which serves to make good waste in the feed. An evaporator is provided for the production of fresh feed water. A reheating apparatus is fitted on the discharge of the feed pumps. Registered steam pressure Total grate area........ ,, heating surface not covered by water 15 kilogs. 95.20 sq. m. 3000.00 sq. m. 213.3 Ib. per sq. in. 1024.8 sq. ft. 32,292 sq. ft. Registered steam pressure Total grate area ... ,, heating surface not covered with water 15 kilogs. 4.66 sq. m. 210.00 sq. m. 213.31b. per sq. in. 48.45 sq. ft. 2260.45 sq. ft. The boilers are fed by eight Thirion pumps, worked by separate engines. The ventilation of the stokeholds and working under forced draught are insured by eight ventilators. The maximum total power prescribed was 13,500 horse- power at 95 revolutions, with a maximum steam pressure of 12 kilogrammes (170.7 Ib. per square inch) in the steam ehest. The trials gave the following results : The boilers are provided with a donkey pump, which works independently of the feed pumps. Forced draught is obtained by means of a ventilator, placecl in the stokehold. The boilers are fitted with fire- box and ashpit cloors, and gas outlet flues, so as to prevent all return of flame into the stokehold. Engines of the “ Charles Martel.”—The engines of this magnificent ship are illustrated on Plates LVI. and LVII. (Figs. 276 to 278), and by Fig. 279. They are of the vertical type, with three cylinders, triple-expansion, of equal power, driving twin screws. The principal dimen- sions of the engines are the following : m. in. Diameter of high-pressure cylinder 1.130 44i ,, mean-pressure ,, 1.700 fißif ,, low-pressure ,, 2.680 105| Stroke 1.100 43Ä Each engine is provided with a condensing plant, consisting of a wrought-brass tubular condenser, three vertical single - acting air pumps, and one centrifugal circulating pump. The pumps are worked by a separate engine. The high - pressure slide valves are cylindrical, the mean and low-pressure ones are of the flat type and are balancée!. All the slide valves are governed by link motion. The reversing gear, which can be worked by hånd or steam power, Controls the steam admission in the cylinders. The pistons are of cast steel and are conical in shape. The foundation pi ates which carry the crankshaft bearings are of cast steel ; the columns on which the Duration of trial ... ... hours 6 6 4 24 6 Number of engines working 2 2 2 2 2 ,, boilers ,, 8 16 24 24 24 Average revolutions 52.4 70.5 97 87.5 92.7 Total power realised, horse- power 2,186 5,545 14,931 9,800 12,620 Coal consumption pei’ horse-power per hour kilogs. 0.762 0.624 0.796 0.753 0.736 Coal consumption per horse-power per hour ... ... ... 1b. 1.68 1.38 1.76 1.67 1.63 Engines of the Armoured Cruiser “Chanzy.”—The French armoured cruiser “Chanzy” was launched in 1894, and was complétée! some two years later. She belongs to the “ Amiral Chaîner ” type, and the group comprises four ships — the “ Charner,” “ Bruix,” “ Chanzy,” and “ Latouche - Treville ” — the last - named having been launched in 1892. The “ Chanzy” is built wliolly of steel, and is 110 metres long (360 ft. 10 in.); 14 metres beam (45 ft. 11 in.); and 6 metres (19 ft. 8 in.) draught. The displacement is 4,750 tons, and the indicated horse- power of the engines is 8,300. There are two screws, and the speed attained is 19 knots. The armoured pro- tection of ail four vessels is similar, and consists of a belt of 95 millimétrés (3.74 in.) ; the turrets are protected with the same thickness ; and there is an armoured deck of 50 millimétrés (1.97 in.). The armament is as follows : Two 19-centimetre (7.47 in.) guns; sixof 14 centimetres (5.51 in.) quick-firing ; four 65-millimetre (2.56 in.), also quick-firing; four similar guns of 49 millimétrés (1.85 in.), and six machine guns. s