Lightweight Rope Lifts Pipelay Production
01 Apr 2007
Allseas Group S.A., a Swiss offshore pipe laying 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 fibre.
The new rope, which has been
installed on Allseas’ pipelaying 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, said 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 fibre, 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 150m 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 manoeuvre, is
exceptionally durable, and can help avoid injuries. The high strength to weight
ratio of Dyneema polyethylene fibre enables use of thinner ropes that are
easier to deploy, recover and store. The rope made with Dyneema fibre only
weighs 9.8 kg/m; steel wire rope of equivalent strength weighs about 65 kg/m.
BEXCOropes created the load bearing portion of the adjustment
rope from 100% Dyneema fibre. The core of the 136mm 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 fibre, which will
help pipe laying companies improve the efficiency and safety of day to day
operations. Although this is the first use of Dyneema fibrer 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.’






