How Victorian Britain Tunnelled Under the Severn, and the Spring That Flooded It

On the Welsh shore of the Severn estuary, the pumps at Sudbrook lift more than ten million gallons of fresh water out of the ground every day, and they have done since 1886. The reason is a railway tunnel more than four miles long, and a spring beneath it that has never stopped flowing. In October 1879, the men digging that tunnel broke into it, and in a single day six years of work were flooded to the level of the tide. This is the story of how Victorian Britain tunnelled under the Severn. We follow the Severn Tunnel from the ferry piers at New Passage and Portskewett to the opening of the line in December 1886. You'll meet Charles Richardson, a pupil of the Brunels who dreamed up the tunnel and was pushed aside; Sir John Hawkshaw, who lowered it fifteen feet beneath the Shoots; and Thomas Walker, the contractor who finished the job and wrote that "one sub-aqueous tunnel is quite enough for a lifetime". We look at the Great Spring, the cement headwall that holds it back, and the six giant Cornish beam engines built to keep the tunnel dry. At the heart of this film is one of the bravest walks in British engineering. To save the tunnel, the diver Alexander Lambert had to walk a thousand feet along a flooded heading in total darkness and shut an iron door. His air hose defeated him. The inventor Henry Fleuss tried with his new oxygen apparatus and turned back. Then Lambert went in again, wearing it himself, and succeeded, only for the foreman to discover a month later that a valve with a left-handed screw had been turned the wrong way. Then came October 1883: the Great Spring broke in again, and a tidal wave poured down a shaft onto around ninety men, who were rescued by a small boat lowered into the flooded tunnel. We visit Walker's model village at Sudbrook, see what remains of the works today, follow the fates of everyone involved, and test the famous claim that the tunnel would flood in 26 minutes if the pumps ever stopped. Chisel Marks tells the stories of the great works that built Britain, and of the people whose names history forgot. If you believe they deserve to be remembered, subscribe and switch on notifications so you don't miss the next film. And if your family lived in Sudbrook, worked for Walker or drove the trains through the tunnel, tell us their name in the comments. Your story could help put a name back on the record. #SevernTunnel #RailwayHistory #WelshHistory #VictorianBritain #GreatWesternRailway