‘Jack-up on Jack-up’ vessel could allow 24/7 offshore wind repairs, claims designer

A new 'Jack-up on Jack-up' concept has been revealed that it is claimed could revolutionise offshore wind turbine maintenance by creating a “virtual factory” around blades, allowing for work to go on day and night in virtually all weather conditions.

The four-legged jack-up design, which features a 15-metre-wide working platform that can be elevated to the height of the nacelle, was revealed by Danish naval engineering firm Knud E Hansen.

“With a telescopic weather cover fitted on the platform, work on the blades can be done in practically all weather conditions, day or night,” it said.

This would result in “far more working hours annually than with conventional maintenance vessels and rope access, making it possible to set up a dependable schedule for planned maintenance.”

A large, air-conditioned workshop is located at the aft end of the work platform, it said.

“When the weather cover is deployed, a virtual factory hall is created around the blade," it said. This allows "all types of work to be performed," minimising the need to remove blades and transport them to shore for repair.

A “cherry picker” mounted at the platform’s opposite end would provide access to the nacelle.

Measuring 154 metres in length and 64 metres in breadth, Knud E Hansen said the vessel could service turbines up to 20MW.

That includes replacing nacelles weighing up to 1,000 tonnes at a hub height of 175 metres, and managing blades up to 130 metres long. This can be done while it is jacked up in 80 metre water depths.