Jumbo has completed the transport and handling of offshore wind turbine foundation components for Ørsted’s Hornsea Two wind farm.
Supporting DEME Offshore, Jumbo deployed its K3000-class heavy lift vessel Fairmaster to transport 141 monopiles (MP) and 131 transition pieces (TP) from Rostock (Germany) and Aalborg (Denmark), to Eemshaven (the Netherlands).
The MPs measured between 8.5 m to 9.5 m in diameter and weighed up to 1,285 tonnes.
With the 152.9 m-long heavy lift vessel, with two 1,500-tonne capacity cranes, Jumbo could offer three different loading configurations without intermediate standby periods for re-configuration: five MPs loaded on deck and in the hold, six TPs and three MPs, or three TPs and four MPs.
“This engineered flexible solution made it an extremely efficient vessel for the project and is one of the things we’re most proud of – it helped us conclude the project scope within just 37 voyages in a period of just under 12 months,” said Jumbo’s project manager Maarten De Gruyter.
The multiple loading configurations also allowed Jumbo to adjust to its client’s planning, which was linked to the delivery sequence from fabrication yards. De Gruyter explained: “We had close cooperation with DEME Offshore with regards to scheduling, and we could handle many changes to the sailing sequence. Ultimately, this meant that we could carry more equipment within less time.”
He added: “During the planning phase, we designed and engineered the MP saddles and TP grillages to deliver our proposed vessel efficiency. We used inlays in the saddles to accommodate the different diameters of the MPs. The clearances were tight: sometimes 50 cm or less between components.
“We also installed project-specific lifting lugs on the deck hatches to speed up loading and unloading operations.”
As part of reducing the environmental footprint of the construction of the Hornsea Two offshore wind farm, Jumbo was required to include a green initiative into its project execution. Jumbo’s chosen solution was to sail with biofuel oil from GoodFuels. This product is expected to deliver 80-90 percent CO2 reduction versus fossil equivalents and contains no sulphur oxide (SOx) emissions.
For Jumbo, the Hornsea Two project is notable because it was the largest number of MPs and TPs that it has ever shipped in a single contract.