Dimensions of a Compound Locomotive.—An express engine built by the Baldwin Loco motive Works for the Philadelphia and Reading Railroad combines the Wootten boiler and the Vanclain four-cylinder compound system. It has a two-wheel or Bissell leading-truck, four driving-wheels 6 ft. U in. diameter, and a pair of small trailing-wheels under the Wootten fire-box. The leading dimensions and particulars of the engine are as follows : Cylinders, high-pressure, 13 X 24 in.; low-pressure, 22 X 24 in. Diameter of driving-wheels. 6 ft. 6 in.; of truck-wheels, 4 ft.; of boiler, 4 ft. 9} in. Form of boiler, straight ; fire-box, Wootten patent. Size of fire-box, 114 X 964. in. Number of tubes, 324; diameter, 1 in. ; length, 10 ft. Beat ing,-surface. fire-box and combustion-chamber. 173.46 sq. ft.; tubes, 1,267.75 sq. ft.; total heat ing-surface, 1,435.21 sq. ft. Grate area, 76.00 sq. ft. Boiler-pressure. 175 lbs. per sq. in. Driving-wheel-base, 6 ft. 10 in.; rigid wheel-base. 13 ft. 10 in.: total wheel-base, 23 ft. 1 in. Weight on driving-wheels, (about) 76,000 lbs. ; on leading truck, (about) 19,000 lbs. ; on trail ing. (about) 25,000 lbs. ; total weight, (about) 120.000 lbs. Weight of tender, loaded, (about) 02.000 lbs. Diameter of tender truck-wheels, 2 ft. 9 in. Coal capacity of tender, 51 tons. Water capacity of tender, 4,000 gal. Brake-fitting. Westinghouse automatic.
Comparative Tests of a Standard Consolidation and a Compound Consolidation Loco motive.—Tests were made in August and September, 1801, by A. Vail, General Master Mechanic of the New York and Pennsylvania Railroad, of two engines built by the Baldwin Locomotive Works, of the Consolidation pattern, duplicates of each other as far as possible. except that one was a standard engine and the other was a compound. The following is a summary of the results of all the tests, viz., two round trips of the standard engine and three round trips of the compound : Theirrbb compound Locomotive.—Before deciding definit ely on the use of compound loco motives, the Pennsylvania Railroad Co., in 1K..49, imported from England a locomotive made by Beyer, Peacock & Co., of Manchester, front designs and specifications of P. W. Webb, Chief Engineer and Superintendent of the London and Northwestern Railway. This locomotive was thoroughly experimented with for over a year, dim ring which time changes were made in its run ning-gear, to adapt, it to the requirements of an Amerienn track. The results of the experi ments showed a saving of fuel over the ordinary engine of from 20 to 25 per cent. Fig. 4 rep resents the engine as altered. The boiler is 50 in. in diallletel% straight. with copper lire-lox 66 in. long, which is built with writer-space below the grates and across the bottom, forming nu ash-pan surrounded by water A brick arch is used in the fire-box. There are four
driving-wheels I; ft. in. diameter. and a pair of loading-wheels. which take the place of the American truck. These wheels are fitted with radial boxes, which allow t he engine to eurve easily, which is proved by the flanges not show-Me-any pereeptible wear. The driving wheels are not connected by side-rods, and are equivalent to two single driver engines in one frame. The laud; pair is operated by two high-pressure cylinders, 14 x 24 in., which are coupled to crank-pins at an angle of 90°. '1'11e front drivers have n shaft with a crank in the center, for one cylinder. The low-pressure cylinder, 30 t24 in., is located underneath the smoke-box. and is operated by exhaust steam from the two high-pressure cylinders when the engine is doing its regular work. This arrangement allows either pair of drivers to slip without inter fering with the other, and by this means the pressure in the receiver is always automatically adjusted. The valve motion is of the radial typ.). The maximum travel of the valve is 34 in. on the high - pressure cylinders, with steam and exhaust - ports 10 in. long. The low-pressure valve travels 410 in. at maxim tun amount, with ports 18 in. long. Steam is taken to the high-pressure cyl inders through a 3-in. pipe to each steam chest, and after doing its work there it is exhausted through two 5-in. pipes around the smoke-box to the low-press ure steam-chest. This receiver-pipe has a safety-valve which is set at 60 lbs., which prevents any excess of pressure accumulating in the low-pressure cylin der or steam-chest. There is a valve ar ranged in this receiver which is con nected with the exhaust-pipe of the low pressure cylinder, which is under control of the engineer, whereby he allows the exhaust from the high-pressure cylin der to pass out of the receiver to the low-pressure exhaust-pipe to the atmos phere, without going into the low-press ure cylinder. There is also another valve operated from the cab, that lets steam from the boiler direct into the low-press nre steam-chest. By these arrangements the high-pressure and the low-pressure engines are made independent of one an other. The engine can also be run to a terminal with either two of the cylinders disabled—i, e., if both high-pressure cyl inders are out of service. or one high pressure and the low-pressure, or with either one of them.
This engine is also equipped with two separate valve - gears. which allow the working of steam at any point of cut-off desired in the high-pressure cylinders without interfering with the point of cut-off in the low-pressure. and ries versa. The exhaust-pipe is attached to each side of the low-pressure cylinder, and passes up above the steam-chest, where the two parts come together, forming one open mg for the outlet.