Batchworth Canal Wall Rebuild

The Project

Initial findings indicated that the structure comprised stone masonry with extensive voids, supported by a solid concrete footing that was reported to be in good condition. Works commenced at the beginning of January under a dewatered stoppage. A 15-metre cofferdam was installed and the channel was drained to facilitate inspection and repair.

Upon dewatering and closer inspection, it became apparent that the wall was in fact constructed of brick rather than stone masonry. The structure had completely failed and required a full rebuild, including the installation of a new concrete footing.

After immediate discussion with the client a new scope was agreed. Additional labour and materials were sourced with minimal delay. The works comprised installation of a new concrete footing, full reconstruction of the brick wall, and completion with a cast insitu concrete coping.

The lock was secured and buoys installed across the canal before the dam was lifted into place with our crane boat. Hand breakers were used to remove the concrete coper and to break out the existing wall.  All arisings were transported by wheelbarrow to a hopper which was boated away for disposal via a grab lorry. A new 300mm x 800mm concrete footing was installed as per the revised drawing. This required an 80m pipe to reach from the Lock Centre across to the worksite.

At the Western end of the works, the new wall was keyed into the existing brickwork.  At the Eastern end we were able to get a tight fit to the existing concrete planks. Granite gabion stone was placed in front of the wall and bonded together with cementitious grout to act as scour protection. A new cast in situ concrete coper was installed as per the drawing.  A retarder was used to create a rustic effect to tie in with the existing coping.

The footpath was reinstated to CRT standard specification.

Despite the unforeseen structural failure and revised scope, the works were completed with only a three-day delay to the original programme.