Page:Walker (1888) The Severn Tunnel.djvu/171

102 accidents, which are unavoidable in tunnel works, occurred.

The first of these took place about 60 yards east from the New Pit at Sudbrook, when we were getting out a length of tunnel in the last week of January, 1882.

The upper part of this length was entirely in coal-shale. The length was nearly ready for the bricklayers, and looked all secure, when a large mass of coal-shale in the face slipped out off a concealed bed of rock, which stood at an angle of about 45 degrees, and in slipping knocked out the whole of the props under the sills. The knocking out of these props caused the sills to break; the upper part of the face then also slipped in, and we ‘lost the length.’ This was the only length we lost in the whole tunnel; and as the total number of lengths taken out was over 1,500, it shows that great care was exercised by the foremen and the miners, to be able to say that only one length of the 1,500 was lost.

The losing of a length in such ground was, however, a serious matter.

It was under the river, but fortunately there were the hard beds of Pennant and conglomerate above the coal-shale, so that we had no reason to fear that the water would break into us.

As quickly as possible the top was secured, and then one of the most difficult operations in mining was commenced, viz., to pole through the broken ground.