Thousands of visitors flocked to the famous Five Rise Locks over the weekend to catch a rare glimpse of the 18th century structure.
British Waterways engineers opened up the Grade I listed lock after draining it for maintenance, revealing the bottom of the Leeds-Liverpool Canal and the 23ft brick walls that line it.
Throughout the weekend 7,000 visitors queued up to be taken into the lock.
Peter Carter, heritage construction supervisor for British Waterways, said: “Me and my little team of eight guys are changing all the top four sets of gates in this lock and the decision was made that while we have it empty it would be a really good chance for people to see what they wouldn’t get a chance to see otherwise.”
The work, replacing four of the six gates on the structure to improve safety, is expected to cost £250,000 and take four weeks to complete.
Mr Carter said: “These locks were built in the 1760s and all they had then was harness ropes, ‘A’ frames, blocks and tackles and muscle power – it’s an incredible feat of engineering.”
Some 3,488 people visited the on Saturday with a 3,660 on Sunday, meaning 7,148 people visited over two days.
Mr Carter said: “As far as I’m aware it is the only set of five rise locks in the country.
“It is a Grade I-listed structure and next to the World Heritage Site of Saltaire – it is an iconic local landmark.”
The lock gates have been in place for 25 years. They will be replaced by oak gates made at Stanley Ferry Workshop in Wakefield – one of only two lock gate workshops in the country.
The water has been kept out of the lock chamber while the gates were removed using stop planks to form a water-tight seal. This enabled the team to carry out repairs to the brickwork, using traditional lime mortar.
Mr Cook said: “Having visited it so many times, to be able this time to walk down inside it, look at the gates and look at the construction, it’s very impressive.” Bingley Five Rise Locks were built by John Longbotham and are one of the major land-marks of the national water-way network. When completed in 1774, thousands gathered to watch boats make the 60ft descent, which can 90 minutes.