31st January 2013
New gates are to be installed at Wheeldon Mill Lock. This is Lock no. 2 on the Derbyshire section. The easiest way to get to it is to walk from Station Road Bridge, by The Mill pub.
Hargreaves Lock Gates are installing the gates as contractors to Derbyshire County Council, which owns this part of the canal. These photos were taken on 30th January.
If all goes to plan, the new gates will be fitted in the week beginning 18th February.
First they have to measure the old gates.
In order to keep the water out of the lock, stop planks are placed into slots just above the top gates. The water is then diverted round the bywash at the top of the photo.
The water comes out below the lock. The pound below the lock has been lowered all the way to Bluebank Lock.
Here you can see how well the stop planks work.
As you can see, the Danger Deep Water sign on the bridge is very accurate.
There are more stop planks beyond the lock. There are pumps to remove any leakage.
Here they are measuring the exact height of the bottom gates.
Note the V-shaped contraption in the water.
Here’s a closer view. This is the bottom cill.
The cill forms a seal when the gates are shut and helps to stop water from escaping under the gate.
Note the hole in the bottom of the gate. This is where the water emerges when the lock is being emptied.
These are the paddles (left) and the winding gear (right) from the bottom gates.
Note that the paddles have a rim round them. Note also the very long rods; compare them to the ladder.
This is one of the two bottom gates. You can see where the winding gear has been removed from the top. The rod runs right down the gate and the paddle fits into the slots at the bottom.
Here’s a close up of where the paddle slots in. When it is raised, the water rushes out through the gates lowering the level in the lock and lowering the boat with it. You can understand why there is a rim round the paddles.
This is the top gate. Note the curved stonework below it.
When the lock was restored, both side walls were rebuilt, but the curved stonework is original – 240 years old.
Note the hole in the side wall. This is where the water emerges when the lock is being filled.
The top gate is far smaller than the bottom gates.
Note the paddle gear on the right and the rod leading down into the recess.
This is a close up. You can see the paddle in its slots. It is covering a tunnel, or sluice, that comes out at the opening in the earlier photo. When the paddle is wound up, it lets the water into the lock. This raises the level, raising the boat with it.
This diagram might help you understand.
To see a video demonstrating how locks work, click here.