HelWin Beta jacket sets sail

The giant steel jacket for the 690MW HelWin Beta converter station is sailing for installation in the German North Sea.

Built for Siemens byHeerema Fabrication Group’s (HFG) yard in Vlissingen, in the Netherlands, the 4,500-tonne foundation will support the 10,200-tonne high voltage direct current (HVDC) transformer topsides that will pull together production from a cluster of wind farms in the offshore Heligoland area.

The jacket, which measures 62 x 42.5 x 42 metres, is being installed by sister company Heerema Marine Contractors and its Thialf construction vessel.

“The EPCI [engineering, procurement, construction and installation] contract with Siemens on HelWin Beta project shows our ability to manage such a challenging and complicated project through all the phases [of the project],” states HFG chief executive Koos-Jan van Brouwershaven.

HFG’s Heerema Zwijndrecht fabrication facility is current working on the final construction phase of the topside, due for completion in the summer.

The Helwin Beta transformer station – one of the 10 "hub" projects designed by transmission system operator TenneT to streamline the transport of offshore wind power onto the German grid – is the third connection in the eastern North Sea.

The first, on track to be completed in spring 2015, will link the Amrumbank West offshore wind farm to the grid via a 45km overland spurline from a converter station in Büttel to the coast, and from there a further 85km directly to the offshore converter station.