Dyneema slings used in wind farm construction

7 July 2010, Urmond - Dyneema ultra-high molecular weight polyethylene (UHMWPE) fibre is helping to ensure that a major construction project to bring clean energy to millions of people in the U.K., moves ahead as efficiently and safely as possible.

The world’s largest offshore wind farm, which is under construction in the North Sea, 23 km off the coast of England, is scheduled for completion in 2012 and the Greater Gabbard wind farm’s 140 turbines will generate 500 megawatts of electricity for the people of London. The turbines are mounted on top of 65 metre, 650 tonne steel ‘mono piles’ that are transported by barge from the Verbrugge Zeeland Terminal in Vlissingen, Netherlands to the construction site.

For lifting the long and heavy mono piles, the Dutch terminal operating company’s safety department wanted a system with better ergonomics than steel-wire and chain lifting slings which are normally used. The new slings would need to be just as strong, or even stronger, but lighter and therefore easier to handle. In addition, previous safety concerns over steel wire rope slings, such as the tendency for the steel wire strands to snap over time and create ‘fishhooks’, prompted the search for a safer solution.

The answer was Ultralift round slings with Dyneema, made by Technotex in Coevorden, Netherlands, which have quickly won the full approval of the operator. “Initial scepticism among our employees has turned into admiration,” says Mattheo Rozemond, responsible for handling the Greater Gabbard mono piles at Verbrugge Zeeland Terminal. “The new slings help our team optimize safety and provide damage-free cargo handling.”

According to DSM Dyneema, manufacturer of Dyneema fibre, the Ultralift slings are just as strong as slings made with steel wire, but have just one seventh of their weight. One result of this is that half as many people are needed to operate the slings, with much less auxiliary equipment, the company says. The operatives are also said to have a healthier environment and are less plagued by shoulder, back, hand and other injuries associated with the older, heavier slings.

“Beyond safety, the Ultralift slings are also contributing to better handling of the expensive mono piles. Because the slings are soft, they avoid damage to the mono piles during the lifting operations. As a result, the cost associated with corrective maintenance is virtually eliminated,” DSM Dyneema says, adding:

“Logistical costs have been cut too. The unloading time of a full shipload of mono piles has been reduced by one full day, saving over € 60,000 in daily rental fees for lifting barges.”

Rozemond is also impressed by the durability of Dyneema, saying: “After intensively using the new slings to unload 56 mono piles, the slings do not show any damage.”