WOOD from the tallest trees in the world will be used to lift four submarines out of the water.

WOOD from the tallest trees in the world will be used to lift four submarines out of the water.

The Navy base at Faslane is to be the home of new highly sophisticated Astute nuclear submarines costing more than £4billion.

Each one of the 320ft long vessels weighs around 7800 tonnes leaving the problem of how to get them out of the water if they need repaired or servicing.

The base already has the only boat lift in the world capable of lifting a nuclear submarine out of the water.

But the Astute posed Navy bosses with a special problem as it has a different shape of hull.

As a result, 45 massive pieces of wood have been delivered to the Clyde base.

They will be put together to create a cradle for the craft which will be sunk into the water allowing the Astute to sail in over the structure.

Huge lifting machines will bring the wood support and the submarine out of the water.

The support is made from Douglas Fir - the world's tallest tree was a 420ft Douglas Fir, chopped down in 1895.

It will be tested when the first Astute arrives on the Clyde next year.

A floating jetty to support the new subs is being built in Greenock at a cost of £150m.