A big operation is planned to replace the lock gates in the centre of York.
The wooden gates control the water in and out of Castle Mills Lock on the River Foss.
They need replacing as they have “reached the end of their serviceable life,” a planning application says.
The upper gates are 3.5m high and the lower gates 6m high. So they will take some moving.
BAM Nuttall Ltd has been tasked with carrying out the work. It plans to install and electric crane onto the lock structure to lift out the gates.
A planning statement says: “Stoplogs will be installed adjacent to the lock gates to isolate the lock to allow works to be undertaken safely and maintain the existing height of the current lock gates.
“All materials to be brought to the site on the barge which will operate and moor outside the lock.
“During its operation, weather events and river levels will be closely monitored and the barge will be stood down in poor conditions.”
A pump will drain the water from the lock. “A fish rescue will be undertaken once the water level is sufficiently reduced for persons to safely enter the lock chamber to perform the rescue,” the statement says.
“The upstream gates will be replaced first, the existing timber gates will be lifted and removed from site using the crane. The new gates will be lifted into place and commissioned before moving onto the downstream gates
“Once the upstream gates have been commissioned the downstream gates will be removed, replaced and commissioned.”
A works compound next to St George’s Field Car Park will be up and running for the duration of the project.
Castle Mills Lock was created in 1796 and rebuilt in 1889. The wooden gates date from the 20th century, but the 19th century cast-iron winding and paddle gear remains.
The York Historic Environment Record states: “The Foss Navigation Act was passed in 1793, and the canal was opened as far as Strensall in c1796.
“In 1859 York Corporation gained an Act to abandon the Foss Navigation except for just over one mile in York. In 1889 the Corporation rebuilt Castle Mills lock for Henry Leetham and Sons, flour millers, to take steam keels.”
Castle Mills Lock was reopened by the Inland Waterways Association in 2021. Volunteers from the association and River Foss Society now operate the lock.
You can book a passage through Castle Mills Lock, but at least two days’ notice is required. Clearly this service will be suspended while the lock gates are replaced.