Ham Mill Lock October Update

Ham Mill Lock Restoration Update

Les Morris reports on the volunteer led restoration of Ham Mill Lock.

Lock Chamber & Gate Recesses

Repairs to the stonework near and in the lower gate recesses have been completed.
Whilst the wing walls on both sides above the lock have been rebuilt and the coping stones replaced. Repairs to the brickwork in the paddle chamber arches have been completed, the formers removed and coping stones re-set and stop-planks have been installed. The Aqua Dam, a large bag full of water, will shortly be drained down and folded away for future use elsewhere

Towpath

Work to realign the towpath to allow operation of the lock gates and paddles has been completed. This process involved casting concrete to move the towpath further away from the lock and repositioning the fence. A constructive meeting has been held with the owners of the adjacent land to agree positioning of the fence and work needed on trees.

Spill-weir

The spill-weir has been repaired. and repointed. A number of Ecotricty staff assisted the CCT volunteers with bricklaying and pointing. Silt was dug out from the outlet and it was flushed out by pumping water through. The water is now running out clear.
The by-wash outlet below the lock has been rebuilt, by repairing the brick arch and rebuilding the fascia with original stones.

Offside Lockside

Work has continued on the levelling of the offside lock-side area. The curved brick retaining wall has now been capped with Cotswold stone coping. The wall also includes the carving of a Severn Trow by local artist and Trust Member James Pentney.

Below the lock

Stop-plank grooves have been cut and steel channels installed. Scaffolding has been erected, and coping stones removed to enable repair of the lower walls.

Lock approach wall

Following recommendations from Stroud District Council’s engineer construction of a gabion wall was commenced on the offside bank on the western side of the bridge. See the bottom picture.

The purpose of the gabion structure is to reinforce the bank above the canal.

This involved removal of many years of accumulated material that had formed the sloping bank down into the canal channel on the west side of the bridge arch. This material had covered the original offside wing wall.

Removal of the material revealed the wall's poor condition and the fact that it had clearly collapsed long ago.

John Berry, a geotechnical engineer, was called in to make recommendations on how best to deal with this issue.

John's recommendations include a new concrete wall braced by a concrete base cast across the canal channel to the towpath wall.

This structure will be installed in sections. It is likely that a contractor will be engaged for this work.

Project Manager's praise

CCT Volunteer Martin Gray, one of the Ham Mill Restoration Project Managers, comments… "The success of the Ham Mill Lock restoration demonstrates the effectiveness of having a dozen or more well motivated people turning up each day.

"Around 30,000 bricks have been laid and, whilst we might be about a month behind our projected schedule, the whole thing is great example of what CCT volunteers can do. One of the elements that has helped achieve what we set out to do has been materials arriving on site on time."

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