Bosses at Manx National Heritage admit they don’t know how long the Laxey Wheel is going to be out of action.

A decision was taken last Friday to stop the Lady Isabella turning after a routine inspection found structural damage to a connecting timber rod.

Daniel Spencer, MNH site supervisor for the Laxey Wheel and the Grove Museum, said the decision was taken within half an hour of the damage being discovered - an indication of just how seriously the problem is being taken.

He said: ’We don’t know how long it’s going to be out of action.It’s sad not to have her turning but it’s safety first.’

Mr Spencer said routine inspections are carried out every week and on Friday, the issue with the beam was identified when debris was found on the platform underneath.

The fact that the problem had developed so quickly was a clear concern. Mr Spencer said: ’It’s very, very rotten. It may still be structurally sound in the middle but it’s not safe to have it moving.’

Mr Spencer said if the wheel had continued to operate and the problem had got worse, it could have caused the counter balance to drop and the sudden jolt of that could cause damage to the crank and elsewhere.

The crank converts the rotational movement of the water-driven wheel into a horizontal motion of the beam which would have at one time driven the mine pumps further up the valley.

In a worst case scenario, debris or even the beam itself - which weighs several tonnes - could have fallen, with an obvious risk to the public.

Engineers are assessing how the beam can be replaced. But in the meantime the attraction remains open to the public, even though the wheel itself is not turning.

Mr Spencer said: ’Nothing has been decided yet. It is not a simple case of replacing a bit of wood. She’s very, very old. All parts of the wheel have got traces of wear and tear.

’It has to be preserved - especially something as unique as this. It’s a big job and obviously a very important one.’