Repairs and dredging. Scheme started in May 1999 and was completed by March 2001.
- Client: British Waterways North West
- Design and Supervision: British Waterways Technical Services
- Contractor: Amalgamated Construction Co. Ltd.
Repairs and dredging. Scheme started in May 1999 and was completed by March 2001.
This is the most demanding and time consuming scheme in the restoration of the canal and is scheduled to take almost two years to complete. Forty per cent of the tunnel is through unlined rock. The remainder is fully or partly lined in either brick or masonry. There are four major rockfalls to be repaired in the tunnel, 16,000 tons of silt and debris to be removed, plus extensive rock bolting and relining works. The constraints of working underground make this an exciting engineering challenge. The photograph shows a shaft bottom structure in an unlined section before work starts. The restoration of Scout tunnel, Mossley is included in this contract because of the similarities between the two tunnels and the required work.
The full 5200 metres length of the tunnel has been desilted. This material has been flushed from the face and pumped to a holding lagoons in the canal at Diggle and Tunnel End Marsden. It has then been pumped to a centrifuge for clean water to be separated from the solids. The water is returned to the canal and the solids are taken by skip to a licensed tip. This photograph shows the treatment plant at Tunnel End Marsden.
The operation at the face has been dirty and arduous.
The shafts have been inspected ahead of the desilting operation and repairs made. Around 4,000 rock bolts have been installed in an operation which follows the desilting work. This photograph shows rock bolting in progress.
The stabilisation works use a variety of techniques depending on the condition of the tunnel. Here steel mesh is attached to rock bolts in the roof and sprayed concrete is to be applied.
This shows a finished section of sprayed concrete used to stabilise relatively small areas of the tunnel. Happily large areas of bear rock will remain exposed for future generations to see.
The Grade II* listed portal structure at Tunnel End Marsden has carefully been taken down stone by stone and reconstructed using traditional lime mortar and tied back to the rock behind.
This is one of four adits fitted with lighting and a tannoy system to act as emergency refuges. The other adits will be inaccessible to boat crews. The view is from the 1849 railway tunnel looking down towards the canal tunnel. Structural work within the tunnel was completed by Christmas 2000. Since then British Waterways staff have fitted fenders from a work boat. Tug boats and passenger modules are due to arrive in early April 2001 to test the operational arrangements before the 1st May opening.
May 25th, Tunnel End. British Waterways' George Greener officially opens the Standedge Tunnel.