A novel way to damage a canal lock

 While we wait for CRT to fix the lock gate at Claydon (see previous post). Here's a little tale the CRT man told me about the stoppage at Grants Lock below Banbury last week.

Boaters will know what a bottom gate paddle looks like. They can skip the rest of this paragraph if I'm teaching them to suck eggs.  Here'a very rough sketch I just knocked up.

When you turn the windlass it rotates a cog against a toothed rack which then lifts or raises. The rack is at the upper and of a long rod (usually square section for some reason) and the bottom end of the rod is attached to the actual paddle wich is a large rectangular plate covering a hole in the lock gate. Raising the paddle lets the water in the lock escape, so emptying the lock.

Boaters will also know that when you are ascending a narrow lock, the strong currents produced by the water rushing in can really shove the boat back and forth strongly.  Two techniques can overcome this. One is to position the boat hard against the top gate and have the engine running in gear. The other is to keep the rear of the boat a yard or so ( or a metre if you prefer) from the bottom gate and using the engine, keep the boat in position by driving it against the current, forward and back, as it pushes and pulls. 

Well at Grants lock, some clever boater had another idea. He looped his stern rope around that long paddle rod, like you might on the riser rods in big river locks. I'm guessing he might have also had his engine in gear pushing forwards. Well those rods and paddles are designed to go up and down only and so when the boat lurched forward the paddle didn't resist much and gave way ,thus emptying the lock faster than it filled. Doh!

So lots of boaters had to patiently wait for CRT to come and fix the paddle. Best part of a day's cruising lost I suppose. I do feel sorry for those poor folks on a week's boat hire when something like that happens.

While writing this we got a notification from CRT that they are offering assisted passage through the broken lock gate at Claydon (see previous post), so it looks like it's not fully fixed but they need to clear the backlog of queueing boats. So I guess we might at last take Herbie up the hill today. Gonna be scorchio!