| Work Detail |
Knud E Hansen’s four-legged vessel concept is designed for all kinds of work on turbines up to 20MW
Knud E Hansen has designed an offshore turbine maintenance platform.
Measuring 154 metres in length and 64.4 metres in breadth, the vessel is designed for all kinds of maintenance work on machines up to 20MW, including replacement and handling of nacelles weighing as much as 1000 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.
The “Jack-up on Jack-up” four-legged vessel concept features a 15 metre-wide working platform.
The ship can be elevated to the height of the nacelle, thus providing a safe platform for maintenance work on the blades eliminating the need for hazardous rope access.
With a telescopic weather cover fitted on the platform, work on the blades can be done in practically all atmospheric conditions, day or night, resulting in more working hours annually than with conventional maintenance vessels and rope access, making it possible to set up a dependable schedule for planned maintenance, said the company.
A large, air-conditioned workshop is located at the aft end of the work platform, and 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 provides the access to the nacelle.
The 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% 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 driver’s cabin.
Two crew access vessels are arranged in davits on the aft deck, and with a retractable boat landing that can reach the water when the vessel is jacked up, the vessel can work as a mother vessel for CTVs working in the area.
This design is patent pending for the “Jack-up on Jack-up” concept, with the elevating work platform, and its unique suspension allowing it to be positioned precisely beneath a turbine blade, and with regard to the weather cover. |
