Operating a Lock

Letting water in to raise the boat is something all the family can do

How to operate a lock

A lock is basically a chamber that holds water and accommodates the boats to either lower on raise them to a lower or higher level. A lock is therefore needed to follow the level of the ground.

Locks are quite simple things, with boats going into the lock then the crew shutting the gate(s) behind the boat.

Going Down

is simply a matter of letting the water out of the other end until the same level is reached, then opening the gate(s) to proceed on the lower level.

Going Up

is just a matter of letting water in the lock from the higher level, until again, the water in the lock is level with that above, then proceeding on the higher level.

Safety tips

Don't open the sluices fully - check how much water is coming in by cautiously opening one paddle half way and making an assessment - you can accidentally flood a boat if you open them too quickly .

Avoid Getting Hung up on the Cill

Remember to keep the boat forward of the top lock gate cill otherwise it can result in the boat sinking or capsizing. The word 'Cill' and white lines are marked on the lock walls and warning signs are placed on lock gates.

Read more information on how to avoid your boat getting hung up on the cill.

Water conservation & Lock etiquette

Always share a lock with other boats if possible. Better to wait a few minutes than to close the gates on an approaching boat and waste up to 56,000 gallons or more of water! For the same reason, always wait your turn at a busy lock. Be courteous and don't prepare locks ahead of you if you can see boats coming in the other direction. Check that no rubbish gets jammed in the gates as this can cause leakage. You will need a boat hook to clear any jammed rubbish, and may need to open the gate again to clear it away.

Always ensure that all gates and paddles are closed after you leave a lock, unless you see another boat approaching, in which case leave the gates open to help them. Never dangle your arms and legs over the side of the boat or the lock as they can get crushed between the boat and lock side.

  • Going Up 
    Close all gates. Ensure top paddles shut.
    Open Bottom paddles to empty lock
    Open doors and enter.
    Close doors and bottom paddles
    Open top paddles to fill lock
    As the boat rises, ensure that the bow does not snag on the forward lock gate
    Open top gates and exit
  • Going Down
    Close all gates. Ensure bottom paddles shut.
    Open Top paddles to fill lock
    Open doors and enter.
    Close doors and top paddles
    Open bottom paddles to empty lock
    There is a sill (step) behind you under the top gate. As the boat falls, stay forward in the lock or your boat may strike it as the water level falls.
    Open bottom gates and exit  


Staircase locks

After operating a few dozen locks most boaters feel thoroughly at home with the procedure but an encounter with staircase locks can forbade even experienced crew. A lock staircase, or riser, is defined as at least two adjacent locks where the upper gates of one lock serve as the lower gates of the next. This means that there are no gaps between locks and on leaving one lock the next lock in the staircase is entered immediately. This method of operating staircase locks is somewhat different from that used for single locks and there is a variety of lock designs which doesn't really help you get to grips with them.

When you are travelling through a staircase you need to think about the direction of the water flow. This is because when you arrive at the bottom of a three-lock staircase, just as a boat coming the other way has left the bottom lock; whereas at a single locks this would be is good news, as you can go in and fill up the lock; with a staircase the top two locks will also be empty so there is no water to fill the bottom lock. You must fill the top two locks before filling the bottom lock otherwise you will not have enough water to take you to the top. This helps to explain why staircase locks need more water; it needs two locks full of water to get to the top where one lock-full from the summit level would suffice on flights composed of single locks, no matter how long the flight. If the staircase had four or five locks there would be three or four locks to be filled using even more water. If you follow another boat up the staircase all the locks are full, you can just empty the bottom lock, enter and fill each lock as you progress up the flight. This is easier and uses only one lock of water instead of two.

Leaving a wide lock - care should be taken to avoid damage to the closed gate