Work has started on repairing and restoring the famous Three Rise Locks at Bingley and when completed they will be as near as possible as they were almost 240 years ago.

British Waterways wants the Grade II* listed structures to look as they did when they were first built in in the 1770s.

The project has meant consulting the Leeds and Liverpool Canal Society and canal heritage expert Mike Clarke.

The work, which involves fitting new oak gates, is expected to take two weeks to finish.

It will include fitting the original style "piggy back" balance beams to replace the single balance beams which have been used in more modern times.

And the paddle gear, which lets the water out, will also revert to the old style system.

Out will go the modern wind-up mechanism and in its place will be fitted the original scissor paddles which open with a sideways motion.

Judy Jones, British Waterways heritage adviser, said: "The locks are changed every about 25 years and over that time the beams and other areas have been altered.

"We are trying at Three Rise, because of their importance nationally, to fit the original equipment.

"It is not appropriate at all locks but because Three Rise is staffed throughout the season it was felt appropriate.

"With that in mind we thought this was just the right opportunity to fit the original equipment.

"It is very important to try to get back to what we believe is the original design."

She said that the original drawings no longer existed so they had consulted experts.

Removing the water had also revealed an unusual feature.

The base of two of the chambers - the top and the middle chambers - had been constructed in stone and the lower chamber had a timber floor.

Mrs Jones said: "It seems unusual that they should have constructed them differently - even so, we think they are the original floors.

"We will be using this opportunity to examine the base of both locks to see if we can understand why they were constructed in different ways."

It was remarkable that the timber floor had lasted so long, although it was badly rotten, she said. The "joists" were broadly still in place but the boards that were laid across were rotten.

"There is no way we will replace anything until we are as certain as we can be that it was original," she added.

The new oak lock gates have been constructed at the British Waterways workshop at Stanley Ferry, Wakefield.

The work is due to be completed by Friday, December 14. There are towpath restrictions and the canal is closed to boating on that section until December 15.

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