Dyneema® vs. Steel Wire: Deeper, Stronger, Tougher

Urmond (NL), April 5 - Deep-sea installation of sub-sea hardware projects now have a high-technology alternative to traditional steel wire rope that offers a significantly longer lifespan, lighter weight and greater safety. Rope made with super-strong Dyneema® fiber from DSM has been shown to outperform steel wire rope when used to place heavy equipment at extreme ocean depths greater than 3km. Testing by TMT Technologies in Huntington Beach, CA, showed that an 80mm rope made with Dyneema®, the world’s strongest fiber, withstood more than twice the number of bend cycles of steel wire. (number of bend cycles where 50% of steel wire is discarded)

In addition, the DSM Dyneema test rope, which next to Dyneema® fibers also contains (limited) quantities of Gore™ Omnibend™ fiber from W.L.Gore and Associates and a proprietary coating, is less than 15 percent of the weight of the steel wire. This property makes it possible to install heavy loads in water depths that heavier steel wire, which can fail under its own weight, cannot reach. For example, templates of more than 250 tons can be lowered safely to the deep sea floor using the DSM test rope made with Dyneema®. Additionally, this lightweight rope is easier to handle and offers the potential to use smaller equipment like sheaves and winches.

Based on these spectacular results, any application where a steel wire rope runs over a sheave or winch is now a potential target for replacement by a rope made with Dyneema®. This innovative product is especially well-suited to applications where safety, durability and weight are becoming a major concern, including ultra-high cranes, mining cables, transport cables and lifting cables.

Mr. Richard Snell, Senior Advisor, Structures and Civil Engineering, BP Exploration, said, “I believe the results of fiber rope development work that have been undertaken by DSM Dyneema will be extremely important for the installation of undersea oilfield equipment in very deep water. This technology is likely to have an impact beyond deep-water installation applications – it potentially can be used in other lifting equipment with benefits from lower mass and inertia.”

Additional Advantages: Cost Reduction and Safety

A major side effect of improved durability is that to achieve the same number of cycles (lifetime) a rope made with Dyneema® can be bent over a smaller sheave. This enables the designer to construct a smaller installation system and thus reduce the costs of the whole operation.

Further, a rope made with Dyneema® is safer than steel wire, which carries a high risk of injury. Loose threads of steel wire can form hooks and cause serious cuts to workers’ hands. And if a wire snaps under the tension of a heavy weight, the results can be disastrous because of the sudden release of energy in the wire. In contrast, a lightweight rope made with Dyneema® stores much less energy - resulting in a less-hazardous break.

Ropes made with Dyneema® and Gore™ Omnibend™ fiber will be offered to the market by selected ropemakers.

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