. The Street railway journal . ,669 ,273 * Credit balances. SCIENCE: ENGINEERING: INVENTION A J500-HP Vertical Engine at Portland, Maine A new unit of power has recently been installed in the ForestAvenue power house of the Portland Railroad Company, con-sisting of a 1500-hp, vertical, cross-compound, Rice & Sargentengine, direct-connected to a 1050-kw General Electric railwaygenerator. The engine has cylinders 28 ins. and 50 ins. in diam-eter by 42-in. stroke, and runs at roo r. p. m. with 120 lbs. boiler three-quarter stroke, which gives the engine great capacity foroverloads, and insur
. The Street railway journal . ,669 ,273 * Credit balances. SCIENCE: ENGINEERING: INVENTION A J500-HP Vertical Engine at Portland, Maine A new unit of power has recently been installed in the ForestAvenue power house of the Portland Railroad Company, con-sisting of a 1500-hp, vertical, cross-compound, Rice & Sargentengine, direct-connected to a 1050-kw General Electric railwaygenerator. The engine has cylinders 28 ins. and 50 ins. in diam-eter by 42-in. stroke, and runs at roo r. p. m. with 120 lbs. boiler three-quarter stroke, which gives the engine great capacity foroverloads, and insures perfect regulation under any condition ofload. Proper motion for the exhaust valve is secured by meansof a toggle joint on each exhaust bonnet without the interventionof wrist-plates. A further advantage of this construction is thatthe moving parts have small mass, and are, therefore, fitted tooperate quietly at comparatively high speeds. The cuti-off latchesoperate without springs, dropping by their own weight, and are. 1500-HP GENERATING SET AT PORTLAND, MAINE pressure. The piston rods extend as tail rods through the headsof the cylinders; the receiver between the cylinders is cylindrical,extending across the frame, and mounted behind it, as shown inthe illustration; the exhaust pipe curves around the frame, andpasses down beneath the floor to the condensers. The throttleis controlled from three positions by means of hand wheels at-tached to a shaft, one at the floor and one at each platform. Thevalve gear is of the Rice & Sargent type, and has silent vacuumdash-pots. The main shaft is 22 ins. in diameter at the armature,The fly-wheel weighs about 85,000 lbs. The valves and valve mechanism of these machines are ofspecial interest. All the valves have double ports, and the exhaustvalves are set nearer the piston than the steam valves, so thatthe clearance is largely reduced. They are operated by directmotion from the eccentrics without the medium of wrist-plates,there being
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Keywords: ., bookcentury1800, bookdecade1880, bookidstreetrailwa, bookyear1884
