Staircase locks
Staircase locks share gates—the downhill gate of one lock is the uphill gate of the next. The Foxton Locks on the Leceister Line of the Grand Union Canal are two sets of five staircase locks, with expanded pounds to supply water.
There is usually a lock-keeper at a larger staircase lock, ensuring that for boats going downhill, only the topmost lock is full and the others are empty, or for boats going uphill, that all the locks are full except for the bottom-most lock. If you try to pour water into a lock that’s already full, it will overflow the gates and the pound walls.
A staircase is negotiated quite differently than a flight of locks. All the locks in a staircase must be turned in the favor of a boat (or boats) going uphill or downhill. On single locks, uphill and downhill boats take turns going through the locks, but the lockkeeper might have several boats pass through the lock in the same direction.
Generally staircase locks are negotiated much faster than a similar number of lock flights, however you may have to wait in line longer
When a crew approaches a staircase lock, many of the usual rules apply. If the nearest gate is open, that’s a pretty good sign the boat can proceed, but the lookouts need to scan the entire staircase to make sure there isn’t already a boat in one of the pounds headed in the opposite direction.
Going downhill, all the pounds except the topmost must be empty. However the “empty” locks should not be completely empty or there might not be enough water to float over the cill between each lock. Going uphill, all the steps except the bottommost should be full.
Unfortunately there’s always a chance on a longer staircase that you might run out of water. Because gates don’t meet perfectly there’s always some leakage—that full pound of water on the top step might not be a full pound worth by the fourth step, so a boat crew might have to let more water into the top step and then bring it down to the fourth step—but not too much water or again you might overflow the pound on the fourth step.
I’ve read posts online suggesting how important it is to contact the lockkeeper when you arrive at a staffed staircase lock. And a lockkeeper can be quite comfortable in a cozy cottage. He might not come out to you; you may have to knock on the door. Whatever you do, don’t go through the lock on your own. A boater headed down against three boats coming up will receive a tongue lashing from the lockkeeper they won’t soon forget.
Longer staircases, however, are often set up differently. There are overflow channels to prevent flooding the pound and holding pounds of extra water to make up a pound that’s too shallow. You should check with the lockkeeper or read any posted instructions on how to operate such locks.
Guillotine locks
They’re not as frightening as they sound. Instead of the gate swinging out, the gate moves up and down like a camera shutter. Sometimes they are electrically operated. Like all paddles, open them slowly at first.