How to work Canal Locks

Working locks, winding paddles, opening gates, safe operation, consideration of other boaters.

Canal locks are probably the most difficult thing to get the hang of, and they require the most physical effort too! We've provided some detailed advice below, but it will all make more sense when you get to your first lock! Remember that hire firms will always take you through your first lock if required.

It might seem confusing here, but in fact most of these things are just common sense that you can pick up by taking it slowly and watching and talking to other boaters. Most boaters will be holiday makers just like you, and happy to chat about ways to do things, the weather and canal conditions. Important safety points are highlighted in the red boxes.

Being able to work locks is essential if you are hiring a boat (you won't get a skipper with it) and handy if you are going on a hotel boat. Some rivers have locks that are worked for you by lock keepers and some canal locks have keepers who may assist you, but mostly you work the locks yourself. Two narrowboats may share a 'broad' lock.

Locks allow canals to go up and over hills and sometimes come in flights of twenty or more. A lock is a bit like a big bathtub that you sail in to when it is nearly empty. You fill it up and then sail out the other end. This lifts the boat up to a higher canal level. Or it lowers the boat down to the lower level if you are letting water out of a full lock.

The main Ďrules of the roadí are - donít rush, consider others and donít waste water. If you come to go up a lock and itís full of water, see if there is a boat coming wanting to go down. It wonít take much longer, it will save water (a lock can use 50,000 gallons of water each time) and it will be easier for you.

If you help another boat with a lock make sure they know what you intend to do. Some people like help, others feel safer when they do the lock themselves. If the lock is big enough to take two boats then share the lock if another boat is close.

Being able to work locks efficiently and safely is really important, you can drain an entire canal if you get it wrong, and, even worse, people have been drowned by incorrect lock operation. Read the information below, listen carefully when you are given instruction and take your time, and wait for someone to help if you are not sure. There are millions of lock operations each year without problems.
YOU SHOULD KEEP AWAY, AND KEEP CHILDREN AWAY, FROM THE LOCK EDGE. Water enters the lock with tremendous force and anyone falling in to the lock or into the canal above the lock could be sucked beneath the water.

What things are called, paddles, gates, windlasses and bollards!

Cut-away lock
To allow the boat to get in and out, and to keep the water in, there are gates at both ends of the lock. Sometimes they are single gates, sometimes double ones. These are called the top and bottom gates and you can only open a gate when the water levels on both sides are the same. So the top gate(s) will only open when the lock is full, and the bottom gate(s) only when the lock is empty.
To let water in and out you wind up paddles, which are a bit like valves, using a windlass. Your boat will come with windlasses supplied.
So to work a lock you need to wind paddles up and down and push gates open and shut. The top paddles let water from above the lock in to fill the lock. The bottom paddles let out the water from inside the lock. Sometimes paddles are attached to the gates, gate paddles, like on the bottom gates here, and sometimes they are free standing ground paddles like at the top of this lock. The water fills the lock through the underground passageway outlined in blue.
Locks usually have wooden or metal bollards that you can wind a restraining rope around.
Paddles may be ground paddles set in the canal bank like the one in the foreground or gate paddles fixed to the gates like the one top right. Most locks have one type or the other. Some locks may have both types, as in this photo. Some locks have hydraulic paddles which look different but have the same effect. Always wind the paddles slowly, checking to see what effect the water is having on your boat.

Be very careful with GATE paddles, when you are going up a lock don't open them when that would direct incoming water into the front deck of your boat!

We've illustrated a narrow lock here, only room for one boat across, broad locks work in the same way but because they are wider and there may be other boats in the lock even more care is needed to restrain boats adequately. Always take extra care whenever there is more than one boat in any lock, boats can get jammed together. There are a number of different types of lock which may have different methods of operation, click to see some different types of lock.

Paddles

Taking a boat up a lock.

Working Locks Safely

If the lock is full of water you must empty it before you can open the bottom gates to let the boat in. Make sure all the gates and top paddles are closed and then wind up the bottom paddles to let the water out. Always check that all top paddles are closed before opening the bottom paddles, otherwise water will just be wastefully running straight through the lock.
When you wind up a paddle don't leave the windlass on the paddle gear. The safety catch on the paddle gear could slip off and the windlass would spin rapidly and fly through the air. People have been badly injured by flying windlasses.
When the water level has dropped enough to let the bottom gates be opened wind the paddles back down again.  
The lock is empty. Open the bottom gates to let the boat in. When the boat is in close the bottom gates. Some people prefer to use the engine to enter and help keep position in locks, others rely solely on ropes. It really depends on the boat and what you feel most secure with.
If you are using ropes make sure you don't drop the rope into the lock, it may get tangled around the boat's propeller. This could stop the engine and leave the boat out of control.
Most people consider the safest position for the boat to be is in the middle of the lock, not touching the top or bottom gates where a fender could catch and hold the boat down as the water rises. If your boat is the full length of the lock you will have to take extra care to make sure that it does not get jammed on any obstruction on the top gate.
Usually there should be at least one person on the boat, checking its position and possibly using the engine to help maintain position, and at least one person operating the paddles and holding a restraining rope.
You will probably need to restrain the boat with a rope, wrapped around a convenient bollard, to make sure it is not pulled around by the rushing water.
As the boat rises the rope will get slacker and must be tightened, so don't tie knots you can't undo, just wind it once around the bollard and take up the loose rope as the boat rises.
Now gently wind up the top paddles to let water in to the lock. Open ground paddles first. The boat will rise to the upper level. Don't use the gate paddles until the boat is above their level to prevent water gushing into the front deck.
Watch the boat all the time to make sure it is not being violently thrown around by the inrushing water and that nothing is holding it down as the water level rises. If at any time there is concern about the way the lock is filling, immediately close the paddles.
When the lock is full you will be able to open the top gates and let the boat out.
Wind down the top paddles and close the top gates after the boat. Don't let the paddles fall on their own, it can damage them, and always check that you have fully closed gates and paddles after leaving the lock.  

Taking a boat down a lock.

Working Locks Safely

If the lock is not full of water you must fill it before you can open the top gates to let the boat in. Make sure all the gates and the bottom paddles are closed and then wind up the top paddles to let the water in. When the water level has risen enough to let the top gates be opened wind the paddles back down again.
When you wind up a paddle don't leave the windlass on the paddle. The safety catch on the paddle gear could slip off and the windlass would spin rapidly and fly through the air. People have been badly injured by flying windlasses.
When the lock is full open the top gates to let the boat in. When the boat is in close the top gates.
You will probably need to restrain the boat towards the centre of the lock with a rope wrapped around a bollard to keep it away from the gates and to make sure it is not pulled around by the rushing water. If your boat is the full length of the lock you must take extra care to avoid being caught on the bottom gate or the top sill as the water falls.
As the boat falls the rope will get tighter and must be let out, so don't tie knots you can't undo. Wind the rope once around a bollard and hold it firmly, letting more rope out as the boat descends. Don't drop the rope into the lock, it may get tangled around the boat's propeller.
Now wind up the bottom paddles to let water out from the lock. The boat will fall to the lower level.
Watch the boat all the time to make sure that nothing is holding it up as the water falls. If at any time there is concern about the way the lock is emptying, immediately close the paddles.
When the lock is nearly empty you will be able to open the bottom gates and let the boat out.
Wind down the bottom paddles and close the bottom gates after the boat. Don't let the paddles fall on their own, it can damage them, and always check that you have fully closed gates and paddles after leaving the lock.


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