Canal boating - working the locks
Working the locks is an inevitable part of navigating the English canal system. You can chugg along for mile after mile without encountering any locks, and then a dozen of them come along all at once! You have to plan your day's run by taking the locks into account--you can't stop halfway through a flight, so do you tackle them tonight or wait until tomorrow?
Working a lock is simple enough, but there is a bit of hard work involved (come on, you need the exercise!) and there is an element of danger if you are not careful. People have been known to get things horribly wrong, resulting in serious injuries and even sunk boats, through being impatient or not concentrating, so before embarking on a canal holiday it's worth being sure that you know what you're doing.
The basic principle of the lock is that canal water is always level, and you can only move a boat up or down a gradient by shifting a body of water "downstream". If you are going down the lock, you go down with the water; if you are going up, the water proceeds downwards after you have left.
Whatever happens, the lock has to be filled and emptied, which involves several thousand gallons of water moving along the canal. At the top of a flight of locks, water has to be supplied to the canal, and at the bottom it may have to overflow into local watercourses if the canal becomes too full. In places, water can be pumped back up to the top. Whatever the circumstances, using a lock has consequences either for water supply or energy consumption, so using locks efficiently is in everyone's best interest.
In practice, this means alternating the movements through the lock between boats going up and down, if at all possible. If a lock is full of water, a boat going down can enter straight away, whereas a boat going up will have to have the lock emptied and then refilled before it can proceed. You should therefore always give priority to a boat going down, even to the extent of sending someone ahead to see if there is a boat just round the next corner. Similarly, if the lock is empty, a boat coming up has priority over one going down.
Assuming that the lock is full when you reach it, send someone ahead to open the gate and let you in. In a narrow canal there will only be one gate, but in a broad canal there will be a double gate. It is always worth pairing up with another narrowboat when travelling on a broad canal, because you save on the number of lock movements, and there will be more people around to do the work. However, if you are alone, you will probably only need to open one of the gates.
A golden rule when opening and closing lock gates is to make sure that nobody is standing on the wrong side of the beam as you do so. Although canals are quite shallow, full locks are not, and you don't want to be pushed into one if you can help it!
In a narrow lock you only need the keep the boat away from the top gate once it has closed behind you, but in a broad lock, especially if you are on your own, you also need to keep the boat straight. This may mean getting someone to hold you to the side with a rope. However, if you have to get off the boat to do this yourself, take care that you have left the boat in neutral and that you will be able to get back on when you need to. Above all, don't tie up and then get back on, because when the water goes down the boat may not go with it!
The reason for staying clear of the top gate once inside the lock is that at the base of the gate there will be a stone or concrete "cill" which is higher than the low water mark. A boat can be severely damaged, or even sunk, if the back end gets stuck on the cill as the water runs out. The extent of the cill is usually marked on the stonework near the top gate.
The person who is not on the boat, having closed the top gate, now needs to work the paddle mechanisms. The paddles are what let the water in and out of the lock, and the golden rule is that they must always be closed except when the water needs to flow. When leaving a lock, you should always check that all the paddles have been closed, but not everyone does this. It is therefore essential to make sure that the top paddles are closed before you open the bottom ones. If they are not, water will continue to flow into the lock as you are trying to empty it.
Paddles are of two types, gate and ground, depending on whether the water flows along channels that bypass the gates, or through the lower parts of the gates themselves. For gate paddles, the windlasses will be on the gate beams, and for ground paddles they will be alongside the gate beams.
Most windlasses on narrow locks are of a ratchet type, so as you wind the spindle, a racked bar rises up and a safety catch clicks into each slot as it goes. It is very important to keep the catch in place, because were you to lose grip for any reason, the gate would crash back down and allow the winding handle to fly off, possibly causing injury to you or someone else.
Some windlasses are very stiff and take a bit of winding, but when you have reached the top, make sure that the safety catch is in place and remove your handle. Another golden rule is to keep your handle with you at all times. Should you leave your handle behind, you'll have huge problems at the next lock!
When one paddle is raised, you will need to cross the lock to open the one on the other side. There is always a narrow bridge across the gate (sometimes it is the beam itself). There will be a handrail, which you are well advised to use!
When the lock is empty, the gates will open quite easily by pushing the beams. Bottom gates are almost always double, and angled to face "upstream" so that the weight of the water in the lock keeps them closed. Once the gates are open and the boat is able to pass out, you can close the paddles. Another golden rule here is never to simply release the catch and let the paddle crash down of its own accord. This can damage the mechanism. Instead, put your handle on the spindle and wind it down with care, bearing in mind that the safety catch will not be in place as you are doing this.
Especially on broad locks, the windlasses may be hydraulic rather than mechanical. They are about as hard to wind up, but they usually go down quite slowly of their own accord if allowed to do so. However, letting this happen is a bad habit that should be avoided.
When one gate is closed, you will now need to get back across the lock to close the other gate and lower the paddle. If you are brave, you step across the gap between the closed gate and the open one, but if not, you have to walk all the way round!
Final golden rule for the time being--always close the gates before you have finished with the lock, unless, of course, another boat is on its way into the lock from below.
This is basically the reverse procedure to that for going down, but with a few points to note.
One is that when the boat is in the lock, water will be rushing in, but it comes into the lock in such a way that it pushes the boat forwards as it does so. The person in the boat therefore needs to control the boat so that it does not crash into the top gate, thus spilling their tea. Some people like to keep the boat hard against the top gate so that there can be no movement of this kind. However, it is also a good policy to only let the water in fairly slowly, by lifting the paddle a few notches, waiting a second or two, and then lifting it a bit more.
The other difference is that it is the top gate that has to be opened and this can be hard work, as there is only one gate as opposed to two (in a narrow lock). The gate will not budge unless the water levels are the same on each side, and this is not always easy to judge. However, when it is ready it will go, although you still need to put your back into it!
Whether going up or down, it is always worth a final check as you leave the lock. Have you closed all the gates, lowered all the paddles, and got your handle in your hand?
Despite all the above strictures, warnings and golden rules, working the locks can be fun! This is when you are most likely to get chatting with other canal users, especially when you are sharing a broad lock or crossing with a boat coming the other way. You can always offer to help, but don't take over if it's not your boat in the lock. Other people may not do things quite the way you would like, so a little patience goes a long way!
More by this Author
Experiments have been made with "meteor burst communication" that involves bouncing radio signals off meteors ("shooting stars").
This is a question that makes a big supposition, namely that men DO find their secretaries attractive! Whether any scientific study has been made as to the proportion of men who fancy their secretaries, I do not know,...
Although views from The Shard are more extensive, the experience of a "flight" aboard the London Eye are still well worth it!