Sluice for draining canal - advice please

[Ian Mac]

This could get really interesting!
Box trunks are a common form of providing a means for draining  a canal. As Pluto has already shown they are standard on the L&L. And also as shown above the Rochdale also uses them.
As does the HVNC and the Chesterfield.
There construction is very simple. A vertical shaft is constructed from a horizontal culvert which runs under the canal below the puddle lining. A elm board is made traditionally these days one may use oppepe. This is placed on top of the vertical shaft and it is then sealed in place with clay which bonds with the puddle clay in the bed of the canal. The board has a chain attached to it and the chain is traditionally hooked onto a hook which is positioned in the wash wall under the water. The site of the hook is marked on the top of the wash wall. On the Rochdale an arrow is used. On the HVNC a roller is provided to which the chain can be attached and the roller has to cross holes in it so a couple of bars can be used to rotate the roller and thus pull the pull up. On the Rochdale winch points were provided by these were deemed to be a trip hazard and that bit of heritage has been got rid off.

On the Ashton, Peak and Macc a different system is used.  A culvert leaves the canal horizontally from the bottom of the bed, and  normally passes under the towpath. This connects at the far side of the towpath with a vertical chamber about 3ft square. This chamber has a set of stop planks in it and then on the far side of these the culvert continues onwards to the stream/river where the water will be dumped. There is a paddle frame which covers the hole as it leaves the chamber. 
The planks as secured with two sets of wedges one set hold the second stop plank down from the top in place and then another pair of wedges secure the top stopplank.
This enable the height of the top plank to be adjusted to the weir level of the canal. The Paddle  is normally left in the open position and it is the stop planks which retain the water. The paddle is closed the top plank removed and all the wedges and this enable the planks to bob and be removed then the canal can be drained by opening the paddle. On the Macc these paddles have a triangular spindle and a special windlass. The outlet culvert is sometimes also used as part of the storm weir system.

[Pagefield]

A chain on the bottom could possibly attract the magnet fishers.

 

Edited February 1, 2022 by Pagefield
spelling