| Summary : The Standedge Canal Tunnel opened in 1811 and allows the Huddersfield Narrow Canal to pass through the Pennines between Diggle and Marsden. It is the longest, highest and deepest tunnel in Britain being 3.25 miles long and 645ft above sea level. Construction of the tunnel started in 1795 and it took a long 16 years to complete. The tunnel's, and the canal's, original engineer was Benjamin Outram. However, due to his many other commitments most of the canal's construction took place under the supervision of a young, inexperienced, surveyor, Nicholas Brown. The slow progress of the tunnel - by 1799 the canal had reached either side of the tunnel - led to Outram's resignation with its completion now being supervised by Thomas Telford. Excavation of the tunnel had been taking place, not only from each end, but also from the bottom of the air shafts. This led to the tunnel being somewhat crooked and Telford discovered that, at one point, the two excavations were not going to meet and they were going to end up with two tunnels. Correcting this has resulted in the tunnel having noticeable bends. The tunnel closed to traffic in 1944 and most of the 20-mile canal died with it. Following the restoration of the canal by the Huddersfield Canal Society, the tunnel reopened to traffic in May 2001. |