Lock 28, also known as Yard Lock, on the Trent & Mersey Canal, in Stone has a rise of 9ft 10in (3m) so the single-handed boater has to treat it with care. The problem with "uphill" locks is that the inward flow of water as they fill first pushes the boat backwards and then pulls it forwards, sometimes violently, into the top gates. One way of dealing with this is to leave the boat in gear against the top gates, but at lock 28 the amount of water coming round and through the gates and lock walls would have flooded the well deck. I therefore resorted to my alternative method of keeping Starcross well back in the lock (it's only 50ft long in a 70ft lock) and using the centre rope to control it in conjunction with one of the much-derided wooden bollards that British Waterways erected in its last years.
As Starcross rose in the lock, the forward pull effect tightened the rope which caught under the jagged edge of a coping stone. This happens frequently and the biggest danger is usually to the rope, but here the coping stone had worked free of the cement holding it in place and was being lifted - and tipped forward - by the rope. Fortunately, I saw in time what was happening and was able to release the rope before the stone dropped into the lock, via Starcross' paintwork or one of the cabin windows! Of course, this meant the boat was pulled forward to hit the top gates, but I have a fender to take care of that.
The same could happen to any other boater using a rope and there's an obvious danger to anyone who should step on the lose stone so I've reported the matter to CRT, who have promised to investigate.
STOP PRESS: CRT have now told me that the stone has been reset and repaired and there is actually proof of this in a picture in today's post on Chance's blog!