Page:Walker (1888) The Severn Tunnel.djvu/300

Rh In the 12-foot Shaft, Sudbrook, one 37-inch plunger-pump, with 10-foot stroke, raising 467 gallons per stroke; the steam cylinder 70 inches diameter, stroke 10 feet; beam engine, horse-power per stroke from water raised 27, from indicator 32·5; ordinary strokes per minute 6½, maximum 9; lift 192 feet.

These three pumps pump tunnel water only—the drainage from the 5-foot culvert—and in dry weather one of them working at the ordinary rate is sufficient.

At the 29-foot Shaft, Sudbrook, three 35-inch plungers, with 9-foot stroke, each raising 376 gallons per stroke (the three 1,128 gallons), and three 34-inch plungers, each raising 355 gallons per stroke (the three 1,065 gallons)—the engines have already been described; steam cylinders 70 inches diameter, 10-foot stroke; horse-power per stroke from water raised, plunger-pump 20, bucket 19; ordinary strokes per minute 7 and 8½, maximum 10 and 12; lift 167 feet. In dry weather only three of these pumps work at one time; one plunger-pump, at least, is among the number, on account of the fresh-water lift.

At 5 miles 4 chains, one 35-inch plunger, with 9-foot stroke, raising 376 gallons per stroke, and one 34-inch bucket, 9-foot stroke, raising 355 gallons per stroke; the steam cylinders 65 inches diameter, 10-foot stroke; beam engine, horse-power from water lifted 15·30 and 14·4; ordinary strokes per minute 7½, maximum plunger 10 and bucket 12; lift 134 feet. Generally only one pump works at a time.

At Benacre, two 20-inch plungers, with 6-foot stroke, raising 82 gallons per stroke, or 164 gallons the two; the steam cylinders 22 inches diameter, stroke same as pump; Bull engines, horse-power per stroke from water lifted 1·32; ordinary strokes per minute 9, maximum 18; lift 56 feet. These pumps drain the cutting, and do not work in summer, the water being raised from 5 miles 4 chains.

On the Gloucestershire side, at Sea-wall Shaft, one 29-inch plunger and one 29-inch bucket, 9-foot stroke, each raising 258 gallons per stroke; steam cylinders 41