Using composite materials in rigging
by Andrew Rice
One of the drivers accelerating carbon’s introduction into the rigging market is the decision of two of the high-tech mast manufacturers, Southern Spars and Hall Spars, to start producing their own carbon rigging products. Where a few years ago they were fitting third-party rigging to their bare tubes, now they are increasingly keen to sell customers a total package: mast and rigging together.
For some customers the package is an attractive one, although Sargent points out that when a mast builder is promoting his own rigging it doesn’t mean it’s the most appropriate for the job. He advises customers to ask some hard questions and do their own research before choosing which type of composite rigging.
‘Each type of product has its advantages and disadvantages,’ says Sargent. ‘What’s happened is some of the mast builders have gone into manufacturing one style of rigging, and so they’re promoting their style.’
Navtec, it should be said, is now developing its own carbon product, while Future Fibres has recently gained Germanischer Lloyd approval for its first carbon product, so it will be interesting to see what further developments come out of this rapidly changing part of the market.
One of the attractions of carbon fibre is its resistance to fatigue
Carbon rigging specialist Carbo-Link is not a familiar name to the wider sailing world, although the Swiss company has been producing custom carbon fittings and rigging for Alinghi over the past two cycles of the America’s Cup. Now it is looking to bring its high-end expertise to a broader market.
One of the attractions of carbon fibre is its resistance to fatigue, as Andy Winistoerfer, director of Carbo-Link, explains. ‘It requires a bit of a change in the way of thinking, because carbon has inherently completely different properties which would allow rigging to have a lifespan comparable to a mast tube, and not really need to be replaced as often as is probably the current standard,’ he says.
Although the carbon rigging manufacturers make strong claims for the longevity of carbon in their marketing literature, they acknowledge the limiting factor is not so much the rod itself, but the terminations – how the rod is terminated at the mast and the deck. A lot of development is going into this area, with manufacturers using a variety of different termination technology. Reducing the size and weight of these terminations is one of the key battlegrounds in the racing market, where professional teams will go to great lengths and expense in the quest for reducing weight and windage by a few percentage points, or even a fraction of 1 per cent.
In its early days, critics of PBO pointed out its fragility if the raw material is exposed to UV or saltwater
In the superyacht world, where people are still waking up to the huge weight saving to be made over rod rigging, such differences are likely to matter less. Rather, reliability and durability are likely to be the more significant factors in determining which type of composite material to use.
In its early days, critics of PBO pointed out its fragility if the raw material is exposed to UV or saltwater. However, those doubts have subsequently proven largely unfounded, with braided coverings providing ample protection from UV exposure and moisture, and resulting in millions of miles of trouble-free sailing.
Carbon fibre has yet to establish the same track record outside of the grand prix race world, although the majority of the fleet in the last Volvo Ocean Race used Southern Spars’ EC6 product for their lateral rigging, and it proved very reliable.
EC6 is made up of a cluster of rods encased in a braided coating to protect against chafe and impact. Some of the newer products on the market such as Future Fibres TSC, Carbo-Link and Hall Spars’ SCR rigging are constructed from solid carbon. Indeed, SCR stands for solid carbon rigging. The potential advantage of a solid carbon rod is less windage due to the absence of the braided covering and because there are none of the tiny gaps that exist between each of the thin rods that make up a clustered product.
However, the potential downsides are carbon’s resistance to impact and its limited coilability. While carbon fibre has great tensile strength it is also a potentially brittle substance. Sargent believes this is a worry that most superyacht owners won’t want to deal with.
‘You want to be able to go a long distance for many years without worrying about it, and not having to worry about what damage might be done by a boom clattering against it,’ he says.