Over 100 transition pieces transported in cost-effective marine scope for world’s biggest wind farm
ALE’s offshore engineering expertise enabled them to complete the marine transportation, sea-fastening, load-out and ballasting of over 100 transition pieces (TPs) for one of the biggest offshore wind farms in the world, Ørsted’s Hornsea Project One.
As well as drawing on new and innovative equipment for the first time, ALE was able to utilise the experience of their Conbit operation for the project’s structural engineering and provide a cost-efficient and safer solution.
ALE’s scope on the project began with the load-out of the TPs, each weighing 337t and measuring 25m high, from the fabrication yard onto the barge. Conbit provided the engineering for cost-effective storage and SPMT stability during the ALE transport operations at the yard. As ensuring stability during the SPMT move was challenging, Conbit provided the engineering to enhance the hydraulic stability during the monopile positioning in relation to the sling configuration (used for loading onto the SPMTs) and positioning within the support cradles. Conbit designed monopile cradles for the storage at the quay. These were specifically optimised to reduce costs, as the need for welding works is reduced.
For the structural engineering, the Conbit team performed the structural integrity and sea fastening calculations of the grillages on the barge deck of the SARAH S barge. Once on the barge, the TPs were transported on the River Tees to the discharge berth.
The project was the inaugural job for ALE’s innovative SARAH S barge. It is 3m narrower than most North Sea barges, making it ideal for this project, as the barge could fit between the quayside and the offshore installation vessel, and fell in line with the vessel’s crane radius limits for transferring the TPs from the barge to the installation vessel.
ALE provided the full, specialist marine scope of work for these operations, which demonstrated the breadth of ALE’s internal expertise and ability to provide unique, tailored solutions. Combined with the strength of the ALE – Conbit collaboration, ALE showcased their ability to provide a complete service package.