Allelys has completed its second and third packages of work for the Dogger Bank B onshore converter station, part of the world’s largest offshore wind farm.
The scope of work included receiving four transformers, each weighing 255 tonnes and measuring 9.3 m x 4.2 m x 4.8 m, at Albert Dock in the port of Hull and transporting them to the site. Allelys was then responsible for the installation in their final positions.
Initial pre-works and engineering studies suggested that Albert Dock would be unsuitable for offloading the transformers and that the project may be at risk of a significant setback. However, Allelys’ in-house engineering team developed a bespoke crane mat and load spreading system to enable the lifting operations to proceed whilst adding vital protection to the quayside.
Allelys also rigged an LG1550 mobile crane to load the transformers onto a 12-axle SPMT, which transported the loads across the docks to a suitable transhipment area. The transformers were then loaded on to Allelys’ Faktor 5.5 girder frame trailer, with 350 tonne capacity, ready for transportation to site.
The girder frame transportation took place over four consecutive weekends. Moving one transformer at a time before going back to reload the next. This carefully planned operation provided a seamless solution for the client to receive the transformers in a more efficient time frame.
Once each transformer arrived at site, each unit was installed using a combined approach of turntables, jacking and skidding systems, allowing Allelys to turn, move and install the transformers in their designated bay.
The first offshore wind turbine for Dogger Bank, meanwhile, was recently installed by Jan De Nul Group’s jack-up installation vessel Voltaire.
GE Vernova’s Haliade-X 13 MW turbines are being installed at the site, one of the largest and most powerful globally. This is the first time Haliade-X units have been energised offshore anywhere in the world.
