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One of the last railways to be built in the broad gauge. 4.75 mile long; it connected with the Great Western Railway at Awre
1856 The company was incorporated.
The line was intended to run to a new harbour to be built by a separate company at Brimspill on the River Severn. By August 1860 the branch from the South Wales line to Brimspill was completed. However, the dock at Brimspill, with its intended coal staiths, was never completed. Permanent way had been laid to within 20 chains of the shore, and construction rails to within 2 chains.
1868 Line opened
1872 The gauge was converted. 
A summary of the history and route, together with a list of surviving and lost features, including bridges, may be found on the Historic England Heritage Gateway website