Two massive prototype turbines are being constructed in the Highlands in a trial for offshore wind generation

The former oil fabrication yard at Nigg, in Ross-shire, is able to cope with the scale of the project

Once erected the turbines will be 146m from the tip of a blade to the base under the sea

Developers hope a full 200-turbine wind farm would produce enough renewable energy to power the city of Aberdeen

The nose cones weigh 60 tonnes each and the total weight of each turbine will be 1,000 tonnes

The turbines will be mounted on jackets which have been towed to the Beatrice Field