I am very grateful to canal expert Cyril Wood for drawing my attention to this fascinating shelter on the banks of the Bridgewater Canal between Moore and Daresbury in Cheshire.
The shelter was provided to protect lengthsmen who would patrol the canal looking out for bomb damage to the canal banks. (The canal was a vital transport link between Trafford Park, Manchester and Runcorn - and hence Liverpool Docks.) If the canal suffered a direct hit and water started to leak from it, the stop planks would be swung into position by the crane to prevent the canal being drained along its whole length. Cranes and planks were situated around every two miles along the canal, so these relatively short stetches could be isolated to facilitate the repair of the canal banks without too much disruption of the transport link.
The photographs were taken in 2014 and the condition of the shelter has since unfortunately deteriorated. Nevertheless, its remains may still be seen near Moorefield Bridge - OS Grid Ref. SJ 574 833 .
This next photo show the location of the shelter near Moorefield Bridge. The shelter is a little way from the canal along a short path which begins about two thirds of the way up this picture, on the right hand side. One of the cranes and sets of stop planks may be seen on the other side of the canal.
And here is a close up of the same crane and planks, still in amazing condition so long after the war. You can easily see the concrete channel or groove into which the planks would if necessary be slotted - just to the right of the base of the crane.
Larger hi-res versions of these photos may be seen if you click on them.
Further information about the Bridgewater Canal - and many others - may be found on Cyril Wood's website.