Using a lock can be a bit scary the first time but it's easy when you know how.
First, some lingo:
- Gates - the lock's big doors at each end
- Paddles - the sluices at each end, which you wind up to fill or empty the lock
- Windlass/lock handle/lock key - the winding tool you need to work the paddles
- Lock landing - stretch of towpath above and below the lock, for use only while using the lock
- Line - rope
- Pound - stretch of water between two locks.
Landing at a lock
Use the lock landing just before the lock, where there are usually bollards to use. This area is for locking through only - you'll get tutted at (or worse) if you moor up there to have lunch etc. because you'll be in the way. In some places, the lock landing bollards or rings are painted a special colour (yellow in London).
If landing below the lock, make sure you moor securely, as you won't be able to keep the boat steady once the lock starts emptying.
Setting the lock (for locks with double-gates at each end)
If the lock is set in the 'wrong' direction for you (i.e. it's full when you need it empty or vice versa), then do the following (otherwise skip to 'Using the lock'):
- Close all gates and make sure all paddles are down.
- Raise both paddles at the end of the lock closest to you. Hold the windlass firmly - don't let it go as it will fly off, possibly into your face. Make sure the ratchet on the paddle is engaged as you wind, so that the paddle doesn't fall back down.
- When the lock is empty/full, nudge a gate to see if it will open easily, but don't open it yet.
- Wind down the paddle on the side furthest away from your boat. (To wind down the paddle, wind it up very slightly, hold and release the ratchet and then, keeping firm hold of both windlass and ratchet, wind the paddle down.)
- Cross the lock.
- Open the gate on the side nearest your boat. Wind down the paddle on that side.
- You should now have one gate open and both paddles down.
If you do things in this order, it will save you crossing the lock more times than you need to.
Using the lock
- Slowly, steer your boat into the lock and hand the centre line (rope) to your crew (if no crew, climb onto the bank and wind the line around a lock bollard for one turn only).
- If you're sharing the lock and are first in, make sure your boat's out of the way of the one following and hold it tight to the side. If their boat is first in, be careful not to knock it as you go in. There's no shame in going in very slowly or stopping if you have to.
- Close the gate(s).
- At the far end of the lock (in front of your boat), wind up the paddles on each side.
- Make sure the boat is held steady. Vital: make sure your boat is a good distance from either set of gates - otherwise it can hang up on something. If you're going downstream, make sure your boat is forward of the cill marker - if it isn't, it'll hang up and sink.
- When the water levels have equalised, nudge a gate to check it will open easily but don't open it yet.
- Cross the lock to the side opposite your boat and wind down the paddle.
- Cross back over the lock and open the gate on the side nearest your boat.
- Close the second paddle.
- Steer your boat out of the lock.
If you're locking through with another boat, it's their responsibility to manage their side of the lock and yours to manage your side, unless one boat has two or three crew and the other none, in which case the lone boater will tend to stay at their tiller and be generally looked after.
...are paddles on the gates at the top of the lock - they let water straight through the top gates. Not all locks have them, but if yours does and you're heading up the lock, first open the paddles on the bank (called 'ground paddles'), wait until the lock's half-full, and only then open the gate paddles. You risk flooding your boat otherwise, and sinking.
Leaving the lock
Cardinal sin #1 - paddles left up - don't do it!
If you leave the paddles up, Liam Neeson will come and find you, wherever you are, and you might not survive. Always close the paddles - it's really annoying to find a lock with paddles left open because you would only do such a thing if you thought the universe was made just for you to use.
Relatively minor sin - gates left open - better to close them.
After you've left the lock, unless you can see another boat coming towards you to use it straight after you, then close the gates - it stops water being wasted.
...this handy video from CRT on using a lock.