Danish firm unveils new design of wind turbine maintenance jackup
Danish naval architecture firm Knud E. Hansen recently unveiled a new design of self-elevating platform optimised for the maintenance of offshore wind turbines.
The four-legged jackup vessel features a 15-metre-wide working platform, which can be elevated to the height of the nacelle, thus providing a safe platform for maintenance work on the blades by eliminating the need for hazardous rope access.
Knud E. Hansen said that, with a telescopic weather cover fitted on the platform, work on the blades can be done in practically all weather conditions, day or night, resulting in far more working hours annually than with conventional maintenance vessels and rope access. This then makes it possible for operators to set up a dependable schedule for planned maintenance.
A large, air-conditioned workshop is located at the aft end of the work platform. When the weather cover is deployed, a virtual factory hall is created around the blade, allowing all types of work to be performed on the blade, minimising the need to remove the blades and transport them to shore for repair.
Additionally, with the possibility of inserting an X-Y motion-compensating system between the work platform and the platform carriers, the “factory hall” can remain geostationary. A “cherry picker” mounted on a hammer head at the platform’s opposite end will meanwhile provide the access to the nacelle.
A main crane is fitted on the elevating structure, allowing for the use of a conventional pedestal-mounted crane with a boom that is approximately 30 per cent shorter than that of a conventional wind turbine maintenance vessel, which should be able to reach the same height, providing a much better view of the blades and the nacelle from the crane operator’s cabin.
Measuring 154 metres long by 64.4 metres wide, the jackup is designed for all kinds of maintenance work on wind turbines up to 20 MW, including replacement and handling of nacelles weighing as much as 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 metres water depth.
