Ancient wood being used to fix water wheel in St Peter’s
MODERN technology is giving way to one of the oldest materials known to man in repair works on the Le Moulin de Quanteraine water wheel.
The National Trust of Guernsey has owned the site since 1990. A mill there became redundant in the 1930s and the original machinery was lost in the 1960s when it became a dwelling.
Students from the Guernsey College of Further Education built and installed a new water wheel in 1991. One of the apprentices who was involved in building a replacement water wheel in 2012 was the son of one who had helped to construct the 1991 version.
The wheel is fed by water that comes down from La Societe Guernesiaise Silbe Nature Reserve.
Towards the end of last year it was discovered that one of the bearings on which the wheel revolved had seized and the shaft of the wheel was spinning inside it.
NToG council member and property manager Jim Whitmore said it was thought that the bearing had been seized for some time.
‘The bearing was made of steel and as the atmosphere around it is so damp it just went rusty and jammed up,’ he said.
Contractors have now removed the bearing and a replacement will be made of a special wood.
‘Lignum Vitae is said to be the wood of life,’ said Mr Whitmore.
‘It is sourced from the Caribbean and takes 350 years to grow to the point where it can be harvested. It is hugely expensive and is produced under licence.’
The timber could not save anyone from drowning as it so dense that it does not float.
Engineers have honed the steel shaft on the water wheel that will fit into the new bearing which is currently being manufactured to precise tolerances in the United States.
‘Lignum Vitae is self-lubricating and when used for bearings it can accommodate things rotating at high speeds,’ said Mr Whitmore.
It has been used in hydroelectric power plants and as a shaft bearing on USS Nautilus, which was the world’s first operational nuclear submarine.
‘While the wood is expensive it should save money in the long run as it can last twice as long as steel when used in bearings.’
The life of the new bearing could be as long as 20 years, he said.
Work began on the repair before Christmas. The water wheel had to de dismantled in to sections and removed with the use of a crane. The project is currently on hold because of the lockdown.
