Dutch mobile offshore units designer GustoMSC has announced a new collaboration with compatriot designer of motion-compensated solutions Barge Master, to develop a solution to meet the installation demands of the emerging US offshore wind market. Designed as a flexible and cost-effective way of meeting the demand for initial wave of US wind farm projects, while allowing the companies to surmount the difficulties raised by Jones Act restrictions, the Top Feeder Barge solution comprises a Barge Master BM-T700 motion-compensated platform which can be mounted onto any appropriate US-flagged offshore vessel or barge.
GustoMSC will oversee the engineering and integration of Barge Master’s platform onto the chosen vessel. According to Elvira Jansen, Barge Master’s business developer, there is a degree of flexibility in what vessel type may be used, and the ultimate choice will be largely up to the individual client’s own wishes and the particular logistical requirements of a given operation. She suggests, however, that, a barge sized 120m × 30m would offer the “least residual motion and highest workability”.
The solution will facilitate the supply of the European installation jack-ups necessary for the construction of the US wind farms, as, according to Jansen, “there will be no US-flagged jack-ups of sufficient size available in time” to meet the installation demand. She also notes that US ports are often unsuitable for jack-up rigs of a sufficient size, due to the proliferation of bridges and hurricane breakers.
The platform has a footprint of 18.3m × 15.1m, and is fully containerised for swift mobilisation to operational locations. By compensating for the motion of the vessel upon which the platform is mounted, it can offer a stable and safe lift-off surface for a maximum payload of 700 metric tonnes in sea states of up to 2.5m Hs, and is Lloyd’s Register-certified under the lifting appliances regulations. It will hold its position using dynamic positioning (DP) or a mooring system.
Jansen adds that Barge Master is working to increase this payload to 800 metric tonnes, which will be necessary for the installation to meet any “expected increase in turbine size, weights and hub heights” predicted by GustoMSC. Jansen hints at the likelihood of multiple systems being combined “either into a bigger system or multiple systems working together” to further increase the overall payload capacity of the solution. This would have the effect, she states, once payload for each system is increased to 800 metric tonnes, of offering an overall capacity of 1,600 metric tonnes, and consequently allowing the solution to supply the monopiles to the installation sites.
The Top Feeder Barge solution is still in its concept phase. However, the concept has proven itself before, having been involved in performing successful supply operations since 2013, when the first BM-T700 platform was mounted onto a standard North Sea barge to supply Geosea’s jack-up vessel, Goliath, where, Barge Master state, the platform showed compensation percentages of over 95% of the barge’s movements. The system was also used in 2015 as part of the installation of a permanent bridge between a depletion compression platform and a shallow water gas production platform in the Philippines’ Malampaya field.