what is the longest canal tunnel in uk
Standedge Tunnels The canal tunnel is on the Huddersfield Narrow Canal. It opened in 1811 and is the longest and oldest of the four and is the longest and highest canal tunnel in the United Kingdom.[1] The first, single-track railway tunnel was completed by the London and North Western Railway (LNWR) in 1848 on the line between Huddersfield and Manchester and a second, parallel, single-track tunnel opened in 1871. The LNWR opened a third, double-track tunnel in 1894. All four tunnels are linked by cross-tunnels or adits at strategic intervals, which allowed the railway tunnels to be built quickly, reducing the need for construction shafts, as waste could be removed by boat.