Dalby Offshore, in collaboration with Plymouth-based company Manuplas, has developed a new modular honeycomb bow fender to bring greater stability to its vessels in high seas, enabling wind turbine technicians to work longer in challenging sea conditions.
The company’s vessel Dalby Aire has been already fitted with the fender to work on the Greater Gabbard Offshore Wind Farm. “The feedback was excellent and the contract on the Aire has been extended,” said, Steve Bartram , operations manager at Dalby Offshore. The company plans to fit its entire six-vessel fleet with the fender this month.
The new fender allows offshore wind technicians to remain safely at turbines in waves more than 1.75m high, rather than heading back when they reach 1.5m. “The problem isn’t getting the technicians on to the turbine but getting them off the turbine and on to the boat when the seas are tough because they have to go down backwards. The object is to minimise movement of the vessel. The fender achieves that,” Bartram said.
Dalby Offshore worked with Manuplas to build the fender with a special polyurethane compound to create the right grip to turbines’ J tubes. The compound is far more effective than rubber used in conventional hollow ‘D’ fenders, according to the vessel owner.
Bartram explained that scope for working in harsher seas had been limited previously by vessels’ hollow ‘D’ rubber fenders. “In an industry constantly transferring technicians, if 12 can stay on turbines for two hours longer because the vessel can stay out and maintain stability in harsher conditions, that’s 24 hours more work for the client. It offers them huge savings.”
“To achieve that, we needed to develop a compound with enough energy absorption and high levels of friction to stick to J tubes on the turbine and give the stability to keep technicians out in higher seas. The extra hours offered between 1.5m and 1.75m makes a lot of difference to client costs,” Bartram said.
Dalby Offshore, which was awarded a GBP 50,000 grant from the GBP 6 million SCORE fund, invested between GBP 90,000 and 100,000 in its development and subsequent testing programme. The SCORE grant helped to develop the compound further and for the fender to be fitted onto all of its six crew transfer vessels. Dalby Offshore was supported in its SCORE application by Tim Smith, of Dorset-based Saline Marine.