The Canal & River Trust has said lock paddles left raised were cause of the embankment collapse that shut part of the Shropshire Union Canal just outside Middlewich
The Canal & River Trust has said that it is “pretty confident” that lock paddles left raised at both ends of several nearby locks were the cause of the major embankment collapse that has shut the Middlewich Arm of the Shropshire Union Canal just outside Middlewich until further notice.
CRT’s Simon Bamford explained that the raised paddles at the lock below the breach site were spotted and closed, but those at the lock above it were not discovered until much later, allowing the level in the canal to rise as the overflow weir could not cope with the flow, leading to the water overtopping the bank, which then burst.
The resulting collapse saw 2800 cubic metres of embankment material washed out, stranding 14 boats and leaving a small aqueduct over the River Wheelock with its arch unevenly loaded, leading to concerns even though it is structurally undamaged. Repair work will first involve dealing with this, then rebuilding the embankment with ‘reinforced soil’ (it will take about 140 lorry loads), then reinstating the channel lining. To complicate matters, in addition to the engineering planning the work will also have to make allowances for an active badger sett on part of the site.
As we went to press, initial preparation work by contractors Kier had begun with a site compound set up and an access road installed. CRT told Canal Boat that it would be difficult to estimate timescales and budgets with any certainty before the end of May, but that “at the moment our best estimate is that repairs will take 6 months from June at a cost of between £2m and £3m”.
Marple delayed yet again
Meanwhile the reopening of Marple Locks following major repairs to Lock 15 after an emergency closure in September 2017 as a result of movement of the lock chamber wall has been postponed once more.
The condition of the lowest part of the wall has proved to be worse than expected with crushed masonry and missing mortar, and it has needed to be taken down and rebuilt right down to the bottom. This has added a further three weeks work (following earlier delays as a result of problems related to the constricted site, and the need for matching replacement stone to be sourced), meaning that it is not now expected to open until 25 May.
