Offshore wind jackets transported efficiently for assembly

Mammoet-Giant provided a range of high-level engineering and design services, as well as assisting with the transport and integration of the jackets, ready for load-out.

The Greater Changhua 1 and 2a Offshore Wind Farms are located approximately 35km-60km off the coast of Taiwan’s Changhua County. They are being constructed as part of Taiwan’s transition towards renewable energy use.  

Jacket foundations for the Greater Changhua 1 & 2a Offshore Wind Farms are comprised of upper and lower jackets, where Mammoet-Giant was involved, including designing temporary lifting lugs fitted to both the upper and lower jacket sections as they rolled off the production line.

These upper and lower jackets sat on top of the custom support saddles – also designed by Mammoet-Giant engineers – which were used on the self-propelled modular transporters (SPMTs) to transport both upper and lower pieces between assembly stations. This method ensured a more efficient transportation process compared to other methods by reducing the time needed.

As part of this project, Mammoet’s PTC200-DS ring crane was deployed for the first time to Taiwan.

The upper jackets – weighing 270t - were transported in turn around 100m from the storage area to the PTC crane, where they were erected so that the transition pieces could be fitted. A 750t crawler crane was used for the upending operation.

The lower jacket – weighing between 600t and 700t - were then also transported to the ring crane’s location and erected in a similar fashion. Then the upper jackets, now fitted with transition pieces, were lifted by the PTC and mounted on the lower jackets.

The lifting capacity of the PTC200-DS ring crane allowed up to four jackets to be assembled at once at the same location, fast-tracking the assembly work. 

Finally, the completed jacket structures were lowered onto the SPMT/saddle combinations for transport to a storage area at the facility.

Transports of the jackets were conducted using the 96 axle lines of SPMT in two 4-file 24 configurations, with two transport beams. The beams - measuring up to 24m in length - were designed to bear the pile stoppers, allowing the transporters to lift the full jackets using the SPMTs’ integral hydraulic suspension.

During the fabrication peak time, Mammoet tapped into its global network to make sure lifting equipment was available to meet short-term demands.

“Mammoet-Giant has provided strong support during the fabrication of the first Taiwan-made jacket foundations for the Greater Changhua 1 and 2a Offshore Wind Farms. The PTC200-DS ring crane’s high lifting capacity, together with the engineering expertise and solutions shown by the Mammoet-Giant team have provided both time and cost efficiency for the operations” commented Sing Da Marine Structure Corporation.

The Greater Changhua 1 and 2a Offshore Wind Farms will have an installed capacity of 900 MW once completed, enough to provide clean energy to one million households in Taiwan. They are also Taiwan’s first large-scale, far-shore wind farms.