The UK’s deepest single canal lock has been partially drained for a spring clean.

Canal & River Trust volunteers are removing debris and litter from Tuel Lane Lock, on the Rochdale Canal, in Sowerby Bridge, West Yorkshire, in preparation for the busier boating months ahead.

The lock lowers and raises boats almost 20ft (6m) as they make their journeys over the Pennines, the trust said.

The charity said it recently launched its biggest ever volunteering campaign to ask for help protecting its 250-year-old network of waterways and historic structures.

Canal & River Trust volunteer leader Matt Crowley giving the UK's deepest single lock, Tuel Lane Lock, near Sowerby Bridge, West Yorkshire, a spring clean, as the charity prepares its historic waterways for the busier boating months to begin. Volunteers are stepping into the partially drained 20ft-deep lock chamber to remove debris and litter which has accumulated over winter. Danny Lawson/PA Wire

placeholder image — Canal & River Trust volunteer leader Matt Crowley giving the UK's deepest single lock, Tuel Lane Lock, near Sowerby Bridge, West Yorkshire, a spring clean, as the charity prepares its historic waterways for the busier boating months to begin. Volunteers are stepping into the partially drained 20ft-deep lock chamber to remove debris and litter which has accumulated over winter. Danny Lawson/PA Wire

Unlike most locks, members of the public are not allowed to operate the mechanisms themselves, because of its depth and its proximity to a tunnel.

Instead, the lock keepers help crews to negotiate the gates, the trust said.

The lock is so deep because it replaced a pair of earlier locks, when it was built in 1996, to enable the canal to tunnel under a road built on its original level and provide a more efficient route.

Volunteer Maureen Readle said: “I’ve enjoyed lots and lots of canal boating holidays with my husband, we wanted to help give back to the canals by volunteering when we retired.

General view of UK's deepest single lock, Tuel Lane Lock, near Sowerby Bridge, West Yorkshire, as Canal & River Trust volunteers give the lock a spring clean, as the charity prepares its historic waterways for the busier boating months to begin. Volunteers are stepping into the partially drained 20ft-deep lock chamber to remove debris and litter which has accumulated over winter. Danny Lawson/PA Wire

“We get involved in all sorts of activities around Todmorden, litter picking, painting locks, managing vegetation.

“I have also adopted a stretch of the canal too, which my husband and I look after.

“When I took part the first time two years ago, I’d never worn a pair of waders before, let alone being waist high in water, helping to look after the UK’s deepest lock.”

Sean McGinley, regional director, Yorkshire & North East at Canal & River Trust, said: “Lock-keepers, many of whom are volunteers, are the face of the canals and play a vital and iconic role within our charity.

“Lock-keepers have been a presence on Britain’s canals for hundreds of years, although the role has changed over time.

“Today, they help to look after the nation’s beautiful waterways, assist boaters on their journeys, provide information and advice to visitors on the towpath, and maintain historic locks.”