Blisworth Tunnel sections lined with pre-cast concrete rings. It was also used to test out the materials that were later used on the Channel Tunnel. An unused ring is on display near the south portal. Blisworth Tunnel Blisworth Tunnel is a canal tunnel on the Grand Union Canal in Northamptonshire, England, between the villages of Stoke Bruerne at the southern end and Blisworth at the northern end. The northern end is about from the northern end of the Grand Junction Canal at Braunston, Northamptonshire and the southern end about . At 3,076 yards (2,813m) long it is the third-longest navigable canal tunnel
Chirk Tunnel was let in January 1796, and its construction was completed in 1801. The of canal eastwards to Frankton was opened immediately, because of the valuable trade in limestone from the Fron Quarries. The section through the tunnel, which also passed through Whitehouse Tunnel to reach Pontcysyllte was opened in June 1802. The tunnel is claimed to be the first in Britain to have a towpath running through it (along with its shorter neighbour - Whitehouse Tunnel). However, Berwick Tunnel on the Shrewsbury Canal was open by 1797 and included a towpath throughout its length. As the tunnel at Chirk is