February 1 - Project forwarder deugro Denmark A/S, together with partners Conquest Offshore, Amasus Shipping / Abis Shipping, have developed a joint plan for the installation of offshore wind farm components.
The use of a standard offshore barge with a 1,500-tonne offshore crane - the Conquest MB1 (pictured below) - will stay on location and perform on site installation work.
Open-top cargo vessels will supply the heavy components from fabrication yards. The vessels will be equipped with dynamic positioning systems that enable offloading operations without the added risk of mooring the vessel alongside the barge.
The lifting trial was carried out in the Flushing/ Westerscheldt area during December 2012. Two 200-tonne test weights were unloaded by the heavy lift crane barge Conquest MB1 from feeder vessel Abis Dublin.
The test lifts were successfully performed in weather conditions of waves of 0.5 m to 1.5 m, wave periods of between two and nine seconds, and wind speeds of 23 -29 knots.
Netherlands based Siri Marine monitored and recorded the lifting trials, including wave induced vessel and barge motions, as well as the heave motions of the vessel and the crane hook.
Through this new installation concept, the partners say that the time loss for transporting components on board the installation vessel from a nearby port is eliminated. The added advantage is that the feeder vessels can haul components from the actual fabrication sites instead of from a nearby "feeder" port.