This article was published in January 2017 in NautixExpo e-magazine #6.
You’ve probably seen them: loops of Dyneema rope, so called “soft shackles,” or blocks in which certain elements are textile rather than metal. Even textile deck fittings are entering the market and becoming increasingly popular.
This quiet revolution—the movement from hard steel toward soft materials—has been going on for quite some time now. So far, most of the action has been confined to the professional or semi-professional racing community. As always, frontline developments trickle down and are eventually adopted by ordinary sailors.
But if they are not obsessive enough about weight reduction to spend loads of money on minor weight savings, why would they opt for textile fittings? Are they getting cheaper and easier to find? What are the pros and cons? We asked the experts.
New Ways of Attachment
“New, high-strength ropes have gradually changed the development of deck gear,” he explained. “Dyneema, Kevlar and PBO are stronger than stainless steel and about ten times lighter. The fact that it is a flexible material allows new ways of attaching one part to another. You can move things in all directions.”
Another advantage noted by Clausin is rapid handling. Loops tend to be very easy to open and close without tools. “And since there is no metal-to-metal contact, there is no noise. If you look at blocks, the fact that the lashing goes through the center of the block is a real safety factor. If the block breaks, the running line is still kept in place by the lashing,” he added.
No Sharp Edge!
But what about the downside? “These textile products have to be lashed to a very smooth surface,” said Clausin.
“The fact that Dyneema self-aligns to load and has excellent abrasion resistance makes it much more reliable than stainless steel. If load is misaligned with a stainless toggle, metal fatigue and failure can happen very quickly. You don’t get this with Dyneema. The public just needs to be aware that sharp edges will lead to accelerated wear and tear, which is easy to see.”
“The beauty of Dyneema is that it is highly unlikely to fail before a problem is identified, assuming regular inspection. By contrast, metal fatigue from a badly installed toggle, for example, can be impossible to see and lead to a critical failure. For me, this is about education,” he added.
Waiting for the Main Players
Suitable textile fittings are the fruit of fiber products with heretofore unknown capabilities. High modulus polyethylene (HMPE) has been chemically manipulated at the molecular level and stretched in one direction. The result is a fiber with superior characteristics in three important areas: high strength, low stretch and low weight. In addition, HMPE is fairly resistant to UV and mechanical wear. The HMPE-based Dyneema and Spectra fiber brands have proven useful in many applications.
High strength, low stretch and light weight are the biggest advantages of textile.
Antal, a large Italian producer of deck gear, has had success with its low-friction ring, developed to replace blocks and attach to soft connections. Roberto Carrara, CEO of the company, confirms that high strength, low stretch and light weight are the biggest advantages of textile fittings, while susceptibility to wear are the main downsides. He added that prices will come down only with large-scale industrial production. “These products are now made by hand, making them expensive.”
Karver’s Clausin agreed: “It always comes down to the same thing—quantity. As soon as boat manufacturers like Beneteau start using lashing attachments, prices will decrease. I think we’re still at the beginning of this new age.”
Ropeye is another interesting player. Their main product line includes various versions of a through-deck fitting with a Dyneema loop, a low friction ring and a deck fitting that is easy to install and distributes loads evenly.
Founder Jaanus Tamme explained the idea. “When you use textile fittings, you need to protect the loop or lashing from chafing. Specifically designed attachment points like ours provide this, along with easy installation and overall weight savings. We believe equipment like this will be more or less mainstream in the future.” The fittings feature low-friction composite materials with rounded curves and no sharp edges.
Sailboat manufacturers are slowly coming to appreciate the benefits of low weight in general. Lightweight vessels not only perform better, they also generate less load, require less material and cost less. Building lighter craft is a new way of thinking in the industry, and the movement from stainless steel fittings to fiber and textile can be seen as a part of that development.