Innovation with Dyneema® in underwater pipe laying

Allseas Group S.A., a Swiss offshore pipelaying company, has collaborated with DSM Dyneema to improve the safety and speed of underwater pipe-laying using next-generation rope technology. The two companies have worked to replace traditional steel wire rope used to adjust pipelay stingers with a new product from BEXCOropes that is made with ultra-strong, lightweight polyethylene Dyneema® fiber. The new rope, which has been installed on Allseas' pipe-laying vessel Audacia, enables faster, easier and safer operations. "Adjusting the stinger is a critical part of the pipe-laying process because it determines the precise curvature of the pipe as it enters the water," explained André Steenhuis, Allseas Innovation Manager. "The heavy, rough steel wire rope hampered our crews, slowing down our operations. With the rope's high strength and low weight provided by Dyneema® fiber, we can achieve the precision we need more quickly and easily. Our partnership with DSM Dyneema has led to a major advance in pipe-laying efficiency and safety." Because of the heavy weight of the 150-meter steel wire rope, Allseas' crews experienced difficult handling, and higher risk of damage and injury. Also, corrosion shortened the rope's useful life. In contrast, the new stinger adjustment rope with Dyneema® is easy to lift and maneuver, is exceptionally durable, and can help avoid injuries. The high strength-to-weight ratio of Dyneema® polyethylene fiber enables use of thinner ropes that are easier to deploy, recover and store. The rope made with Dyneema® fiber only weighs 9.8 kg/meter; steel wire rope of equivalent strength weighs about 65 kg/meter. BEXCOropes created the load-bearing portion of the adjustment rope from 100 percent Dyneema® fiber. The core of the 136-mm-diameter rope is protected against abrasion by a Deltaflex cover, which is BEXCOropes' proprietary technology. Adjustment ropes, which are kept on a winch, can be subjected to as much as 250 tons of force. Rigo Bosman, Market Segment Manager Offshore at DSM Dyneema said, "We have closely collaborated with Allseas Group and BEXCOropes to perfect new rope technology based on Dyneema® fiber, which will help pipelaying companies improve the efficiency and safety of day-to-day operations. Although this is the first use of Dyneema® fiber in this industry, its strength, light weight and durability have proven their value in many other marine applications, and we see great potential for Dyneema® in new offshore applications such as Abandonment- and Recovery ropes."