New turbine foundation installation vessel

Norwegian engineering company, Ingenium AS Oslo, has unveiled a further example of looking beyond the usual jack-up vessel principle.

The company has an impressive list of clients, many connected with the offshore oil and gas industries, providing services such as offshore handling systems, cable handling and installation equipment and subsea equipment and tools. Earlier this year they established a new company, Ingenium Ventus AS, owned by Ingenium AS, Ingenium employees and selected external partners to design, build and own a turbine foundation installation barge described as ‘cost-efficient and fit for purpose’.

The company proposes two versions of the installation barge, capable of installing all types of foundations, including monopiles, piled jackets, jackets with suction anchors, and also fully assembled wind turbine units including foundations. Catamaran shaped and open at one end, the gap between the two pontoons provides a sheltered area for foundations to be upended by a hinged tilting frame and lowered to the seabed. Capable of a ten knot tow speed, final positioning is achieved using DP and four retractable azimuthing thrusters. The barge can be controlled either from aboard the vessel itself or remotely from a nearby vessel such as the accompanying tug.

A high priority for offshore wind farm developers is reducing the cost of foundations and their installation, a significant part of overall project costs. The light version installation barge, intended for foundations up to 1,000 tons, proposes such savings by utilising the vessel for installing foundations while other vessels (such as jack-ups) concentrate on installing the turbines themselves. While the full size version will be capable of installing fully assembled turbines, Ingenium points out that presently, complete turbines are not capable of being transported horizontally.

Installing jacket or monopole foundations involves skidding or lifting the structure onto the barge (between the pontoons), either directly from the quay, supported by fore and aft skidding/support beams, or from a barge ‘docked’ within, then locked into the tilt frame. Once on site, the barge is positioned using its own thrusters and subsea camera frames are lowered onto the seabed alongside pre-installed piles (if used). The tilt frame containing the foundation is then lifted to the vertical position and the structure lowered to the seabed utilising the camera systems and the vessel’s DP for final positioning. A similar procedure is used for jacket foundations using suction anchors and monopoles, where a pre-installed pile hammer completes the installation.

Classed by Germanischer Lloyd, the main particulars of the barge are 120m hull length, 45m width, 3.4 to 4.5m draft and capable of operating in water depths between 15 and 60m. Model tests are currently taking place and a building contract with a shipyard is planned by the end of the year.