Houlder Lays Out Offshore Support Base Vessel Concept

Research & Development

Houlder’s Marine Design Consultancy has launched a wind farm support base concept design for an Offshore Support Base (OSB) vessel that recreates the convenience of port facilities – but offshore. 

Houlder said that it has been able to turn to a proven design from its Oil & Gas heritage to deliver a highly stable platform with a large and versatile deck plan, as well as high crew comfort and excellent operability.

The DSV (Dive Support Vessel) Orelia hull design has a long history of providing stable, safe and highly operable diving support. Using a proven, highly stable design will significantly improve the comfort levels onboard for future wind farm maintenance crews, the company explained.

Mike Simpson, Director of Houlder’s Marine Design Consultancy, said: “The fact that a windfarm needs people to maintain them is hardly news. Indeed, a workforce is now established that undertakes both routine and unplanned turbine maintenance for nearshore windfarms. The sight of crew vessels leaving and returning to shore is becoming commonplace in a growing number of sites round the UK coast.  Those planning future windfarms are, however, now hotly debating how to replicate this maintenance regime up to 100km offshore. It clearly makes for a more challenging commute.” 

In typical North Sea crew transfer conditions, the Orelia hull design limits roll to  +/- 1 degree. This means a straight-forward walk to work personnel transfer system can provide direct turbine access without motion compensating technology, Houlder said, adding that the design also provides three docking stations for Crew Transfer Vessels’ and a helipad to maximise deployment and crew transfer options.

“Taking Dogger Bank as an example, it is intended that the vessel will stay in the wind farm continuously throughout the summer weather period. It will be re-supplied by standard supply boats, with the crew and maintenance personnel being changed out as required. During winter periods, when crew transfer becomes more challenging, returning the mothership to port on a 28 days’ cycle proves more cost effective,” Houlder explained.

The OSB concept comprises facilities that are based on the latest offshore Oil & Gas standards, according to the company.