Water Saving Wonders - North Rode, UK
Posted by: 
dtrebilc
N 53° 11.689 W 002° 08.718
30U E 557100 N 5894284
This information board tells how the Macclesfield Canal used side ponds on the canal locks as a water saving measure.
Waymark Code: WMQ16F
Location: North West England, United Kingdom
Date Posted: 11/27/2015
Views: 9
The Macclesfield Canal was the last narrow canal to be built in the UK and was completed in 1831. Engineer Thomas Telford designed the canal with all its twelve locks in a short distance, only 1¼ miles, so as to improve efficiency of operation and maintenance.
This information board stands on the side of the canal next to lock 4 and gives information about some of the design consideration of this canal especially its side ponds.
| Water saving wonders | |
In just a mile, the Macclesfield Canal changes height by about 113ft (34 metres) through the twelve locks of Bosley flight - that's nearly 3 metres per lock!
Go with the flow
Each lock had a side pond designed to save half a lock full of water each time it was used. The system was only efficient if there were equal numbers of boats passing up and down the locks!
When a lock was emptied half the water flowed into the side pond and the rest into the lower level of the canal. Every time the lock filled half the water came from the side pond and the rest from the upper level of the canal. Confused? Look at the illustrations to discover how it all worked.
In time the side ponds went out of use, perhaps because they were costly to maintain and there was a good water supply from Bosley Reservoir.
This part of the sign has a series of pictures showing how the side pond works. However this Wikipedia Page goes one better and has a working diagram. |
Restored
In 2009, British Waterways restored some of the original features of this lock, including the stone 'quadrants' underneath the lock beams and the side pond.
You will also see the beautifully restored steps on the far bank that would have been used to aid access to and from boats using the lock.
Look out for
A horse hook - what do you think this was used for?
Cast iron chequerplate on the footbridge crossing the lock
Marks on the bridge caused by the rope as the horse pulls the boat through.
| Horse hooks are used to reduce the effort needed by a horse to pull a boat moving out of a lock. The towline is passed through a pulley on the boat's mast. When the horse starts to pull, the pulley gives a 2 to 1 advantage to enable the boat to move out of the lock easily. |
The patterned deck of the footbridge at the tail of the lock helps to prevent the boatman slipping as he operates the lock. |
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