the grinch

yes Patrick the gate quoin/collar does indeed make the gate fall away from the mid position to fully open or closed

you're welcome to come along next time I'm doing a drain down of one of our locks and you can see for yourself that not only are they tapered vertically but are also slightly tapered lengthways as well, this is to prevent the wall from falling inwards (although it still happens sometimes) our locks have a mix of styles the stone locks have an invert which is curved up from the middle with about a foot rise from the centre to the walls the last lock we have built with a sharp transition from a flat floor invert into the walls there is no rise in the floor at all but there is still an offset in the length of the lock

or better still keep all your crap in the boat or get rid! you wouldn't pile all you stuff on your roof at home would you!! that's the Northern outfall sewer as I previously mentioned crosses the lee and the back rivers yes Alan I hadn't thought of that one but yes it is lower

nothing wrong with that Brian its just the way I use them (single rope / forward gear)

froghall tunnel northern outfall sewer on river lee (but only at high spring tide) burnt mill bridge river stort nell bridge oxford canal these would be on my list as the lowest I've encountered

the only place I would ever consider using a fender is on the Nene and only because of the stupidly installed chains at low level