In Taiwan offshore wind farm specialist Ørsted Taiwan, the Taiwanese division of Danish multi-national energy company Ørsted, commissioned Mammoet Giant, a joint venture between Neth-erlands headquartered heavy lift and transport specialist Mammoet and Taiwanese company Giant Heavy Machinery Services Corp., to marshal 66 wind turbine jackets for the 920 MW Greater Changhua 2b and 4a wind farms at the port of Taichung, Taiwan. 

RoRo is often the preferred method for moving large and heavy offshore wind foundations onto and from vessels at port. In this instance, however, Mammoet opted to use its 5,000t capacity SK350 ring crane for the job instead. 

A key reason behind this is that effective use of the RoRo method is condition dependent – particularly with regards to tides and weather. 

“We considered both RoRo and ring crane options but eventually came to them with a very clean solution of using our 5,000t capacity SK350 ring crane,” explains Joey Yu, manager of operations at Mammoet Taiwan. “This was because the port is quite famous for big tides – sometimes up to six meters in difference. 

“For a RoRo operation, if the tide is not up to a certain level and the weather conditions are poor, it would take much longer to offload the jackets. What we proposed was a solution that wasn’t dependent on those factors.”

The 80-metre tall, 2,400 tonne jackets arrived on a deck carrier in batches of four. They were hoisted from the deck using the SK350 and placed onto concrete supports on the quay. 

The SK350’s centralised ballast weight meant that the entire ring track didn’t need to be constructed on the quay – only the section needed to make the 130-degree slew from vessel to landing support – thus saving mobilisation time and working space.

Next, with the three legs of the jacket elevated on supports, 32 axle lines of SPMT drove un-derneath each foundation and lifted it in tandem, using their on-board stroke. 96 axle lines of SPMT were used in total across the project. 

The jackets were driven to a temporary storage area in the port and placed on steel founda-tions resting on load-bearing mats made from sustainable bamboo. 

The steps were reversed for the final load-out phase – the jackets were driven back to the quayside and then lifted by the SK350 onto a deck carrier, which ferried them to the offshore installation vessel in batches of four. The efficiency of this approach helped to minimise the uptime of high-value assets at sea, says Mammoet.

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