Page:Walker (1888) The Severn Tunnel.djvu/112

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HEAD-WALL OF BRICKWORK.
55

The final struggle—1880. selected a place where the rock seemed sound for building a head-wall to stop back the water from the spring, which we decided to undertake at once.

To execute this work it was necessary to make two dams across the heading with good clay, and between the two to carry the water in wooden troughs about 3 feet square. Under the troughs a chase was cut well into the bottom of the heading; chases were also cut on both sides and in the roof, and in these a strong head-wall of brickwork, in cement 8 feet thick, was built with a door-frame of 12-inch timbers, and hooks to hang the door. The 3-ft. troughs passed through the door-frame, and when the brickwork was completed the shoots were removed and the door hung, but left open.

The bricks, cement, and timber had to be taken up the heading on a rough raft pulled backwards and forwards by a rope; and before any of these things could be done, an air-pipe had to be laid and a supply of compressed air provided for the men.

The brickwork was finished, and the door hung by about the end of the year 1880; and after allowing time for the brickwork to set, the door was closed on the 4th January, 1881, and the water from the spring entirely shut out from the works. This head-wall was 469 feet west of the centre of the Old Pit, and for more than two years from the time the door was shut we had no more trouble from the spring itself.