Page:Walker (1888) The Severn Tunnel.djvu/298

Rh is placed there, on which are stored the spare valves.

A simple contrivance is also provided by which the valves can be changed very rapidly.

The engine-house is traversed in its entire length by a powerful traveller, capable of handling any part of the engine or pumps.

Steam is supplied to the engines from a battery of twelve double furnace Lancashire boilers placed in an adjoining building.

Two main steam-pipes connect the boilers with the engines. These pipes are arranged with sluice-valves, so that the engines can be worked singly or all together.

The temporary pumps used during the construction of the works are as follows:

At the Iron Pit, Sudbrook, two 26-inch plungers (the Bulls), with 10-foot stroke, raising 231 gallons per stroke each, or 462 the two together.

Also one 35-inch bucket-pump, with 9-foot stroke, raising 376 gallons per stroke.

At the New (12-foot) Pit at Sudbrook, a 28-inch plunger-pump, with 10-foot stroke, raising 267 gallons per stroke; also two 18-inch plunger-pumps, with 10-foot stroke, raising 110 gallons per stroke each, or 220 gallons the two together.

At the Old (15-foot) Pit at Sudbrook, erected specially to pump the Great Spring, a 37-inch plunger-pump, with 10-foot stroke, raising 467 gallons per stroke; also a 35-inch bucket, with 9-foot stroke, raising 376 gallons per stroke; and a 31-inch bucket, with 9-foot stroke, raising 298 gallons per stroke.

At Five-mile-four-chain Pit, one 31-inch bucket-pump, 9-foot stroke, raising 298 gallons per stroke ; one 28-inch bucket, 9-foot stroke, raising 240 gallons per stroke; two 18-inch plungers, 8-foot stroke, raising 88 gallons each per