June 18 - Longitude Engineering, a specialist marine engineering company, has won a major contract with A2SEA to deliver the transportation engineering package for the 67 Siemens 6MW turbines at Dudgeon Offshore Wind Farm off UK's east coast.

A2SEA will install the turbines using its purpose-built second generation installation vessel Sea Installer and has commissioned Longitude Engineering to assist with the design of component sea fastenings including the tower and nacelle grillages and blade racks, along with a motions and blade tip immersion analysis for the vessel whilst it is transporting and installing the turbines.

Andrew Butler, managing director at Longitude Engineering explains: "Sea Installer will transport four towers at a time and with the towers 81 m high, weighing 385 tonnes and with a centre of gravity some 35 m above deck on a narrow 6 m radius base footprint, the very high cyclical reaction loads imposed on the sea fastenings and deck structures present specific structural challenges. Although each turbine blade is only 26 tonnes, these relatively lightweight composite structures at a total length of 75 m significantly overhang the sides of the 39 m wide vessel. Our motions analysis allows for determination of the sea state limit for the transportation".

Although this is the first contract awarded to the company by A2SEA, Longitude Engineering has a proven track record in delivering similar services:

"We have a good profile in this market", says Butler. "We have significant market expertise in working with jack-up vessel operators, we know the challenges and the pitfalls and we understand what certification authorities require. Although we are a niche operator, we are a sizeable company with teams operating in the UK, Singapore, Mexico and the United States. This allows us to offer a comprehensive service including motion and hydrodynamic analysis, naval architectural services, structural design and engineering work. Our clients receive a turn-key solution for all technical works."