The unusual work, which required the help of a specialist mining consultant, took two days to complete. A hydraulic bucket on the front of the amphibious dredger, known as a Truxor, was used to clear the blockage so that boats will once again be able to navigate the 3¼ miles through the tunnel.
It is thought that during the unprecedented wet weather, approximately 8-9 cubic metres of sand, gravel and other debris were swept into the tunnel by a stream that flows into the tunnel about 250 metres from its entrance at Diggle.
Mark Weatherall, senior project manager at the Canal & River Trust, comments: “Working deep underground in a tunnel on a floating dredger is quite unusual and poses many new problems which, I am proud to say, the team have successfully overcome in a short period of time. Not only have we had to bring in specialist equipment, we've had to take specialist advice from a mining consultant who is experienced in confined spaces to make sure that the work was undertaken in a safe and efficient way.”