Opened in August 1858, the unlit Netherton tunnel stretches 1.7miles (3027 yards) underground and is a key link between the northern and southern Birmingham Canal Navigations. The tunnel was the last to be built in Britain during the canal age. It was built wide enough to allow boats to pass in both directions and constructed to relieve the bottleneck of the adjacent Dudley tunnel, which had waiting times of eight hours or more, and sometimes several days.
Built using pick and shovel, the construction of this impressive feat of Victorian engineering was not without its risk and during construction nine men were killed and eighteen seriously injured.
Due to the nature of its design and as a result of the local ground conditions, cracks have appeared in the Victorian brickwork with many ‘bunching up' and breaking off. This has caused serious concern for our engineers which have now started the repair works that will safeguard the tunnel's future.
The project will cost £1.5million and involves carrying out repairs to a 50 metre centre section of tunnel almost a mile into the tunnel. Engineers are drilling holes within the tunnel wall, filling these holes with steel tubes which are then filled with concrete. Once set this section of tunnel will also be reinforced with a new arch to create a stable centre section.
George Ballinger, head of engineering at the Canal & River Trust, said: “We have been keeping a close eye on Netherton Tunnel for some time and have carried out various repairs over the years, the last being in the early 1980s. The centre section of tunnel that will be repaired over the weeks ahead has really got us concerned and, ultimately, if we did nothing the tunnel could collapse.
“The works being carried out will help prevent any further movement of the centre section, giving it strength and support for generations to come.”
The works started at the end of last year and are due to be completed in early March. During the works the tunnel and towpath will be closed to members of the public.