The “unusual challenge” of shifting a 64-ton crane which crashed into the Leeds-Liverpool Canal a week ago means no-one can say when it will be moved.

The huge all-terrain machine, thought to be worth £500,000, was being used by the Canal & River Trust. It was doing preparation work to replace lock-gates at Dobson Locks at Apperley Bridge when the accident happened on Friday.

The towpath collapsed under the weight of the Tadano Faun crane, which can lift 90 tons, in an accident the Trust said was “rare”.

Since then the charity and contractor Specialist Crane Hire have been investigating how the accident happened and how to haul the upturned four-axle crane from the water.

Apperley Bridge Marina owner Steve Wright said he imagined moving the crane would be a big job, but hoped it would happen as soon as possible.

“It’s not really affected the marina because the locks were closed anyway, they have been closed since before Christmas,” he said.

“It could affect us though if it means the lock closure goes on for longer than anticipated. Then it will cause us a problem because it will mean a loss of business. If it delays the lock re-opening, it will cause us an issue.”

Acting waterway manager at the Canal & River Trust Iain Weston said: “We’re still carrying out internal investigations to understand how the incident happened. Removing a crane from the canal is an unusual challenge and we’re currently looking into the best way of getting it out safely whilst protecting the environment .

“We can, however, assure everyone that enjoys the canal that we’re working on a plan to get things back to normal as quickly as possible.”

T&A Reader James Higgins sent us a picture, via Twitter, of bemused walkers taking photographs of the crane on mobile phones. He said: “Haven’t got a clue how they will get that out!”

Des Martin added: “As soon as I heard about this, my gut feeling was that it would be there for the duration!”

According to its website, Specialist Crane Hire, in Wigan, loans out machinery under two types of contracts. Under one contract responsibility for risk assessment and damage insurance cover lies with the company, and under the other the customer, in this case The Canal & River Trust, would have to provide the policy and checks.

The charity could not say what type of contract it had agreed to.

No-one was injured in the accident, which the Health and Safety Executive is aware of. The driver leapt to safety before the crane tumbled into the river.

Bungs were placed around it to prevent any fuel spillage spreading and part of the towpath has been fenced off until the crane is moved.

The Canal & River Trust reported the incident to the Environment Agency, but its involvement was not needed. A spokesman said the Trust had controlled the situation.

Specialist Crane Hire would not comment on the accident or the logistics of removing the vehicle.