<P> 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 . 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 . </P>
<P> 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 . 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 . </P>
what is the longest canal tunnel in uk
what is the longest canal tunnel in uk
Huddersfield Narrow
Huddersfield Narrow