Sailing I

Wind is Power

WORDS: SAMUEL JEFFERSON

In 1853 the clipper ship Sovereign of the Seas was racing home from Honolulu to New York with a cargo of whale oil. Slashing through the water under a huge press of sail, she repeatedly hit over 20-22kn of boatspeed, generating through the power of her sails alone some 8,000hp. At the end of a wild and exhilarating day, her Captain recorded that his ship had run 428nm in 24 hours. This was the apogee of commercial sail, when a clipper ship could outperform a steamship on passage. It was a fleeting moment and, by 1940, the last of the great commercial sailing ships was gone. The fact that, less than a century later, we are casting around for viable sustainable alternatives to diesel-powered commercial freighters is a powerful irony.

The return of commercial sail looks a long way off and in their absence, it is Superyachts that blaze the trail in terms of providing a lower-impact alternative to engine power on big boats. Bear in mind that the Sovereign of the Seas was 76m long – significantly smaller than many sailing Superyachts – and it’s clear that the technology being developed by spar and sail manufacturers to create rigs that can tolerate extraordinary loads on very large sailing vessels was foreshadowed by those who designed the final generation of commercial sailing ships of the 19th century. Riggers and sailmakers working on a Superyacht come face to face with the same conundrums of load bearing on a vast scale as their 19th-century counterparts and, while hemp, timber and canvas may have been superseded by carbon fibre, Dyneema and Vectran, the principles remain the same. It is also true to say that the technology they are developing may in time create a pathway back to commercial sail and a cleaner, brighter future.

Back in the 19th century, of course, few if any boatbuilders gave any thought towards environmental sustainability. Now, it is central to the world we live in – and most certainly that of Superyachts. On average, a sailing yacht generates a carbon footprint some 45 per cent lower than its motorboat equivalent, chiefly because its spars and sails can effectively harness the power of the wind. Meanwhile, advances in hydrogeneration enable yachts’ propellers to generate power while sailing at speed under sail, which also means they are capable of arriving at anchorage with full batteries. In turn, this makes it possible to run air-conditioning and electrical appliances overnight without a generator, and the boat’s carbon footprint is
further reduced.

To develop rigs and sails capable of driving Superyachts under sail on such a grand scale places you at the cutting-edge of technology. Two companies operating in this zone are Southern Spars and Doyle Sails: in recent years, both have become accustomed to testing the limits of possibility when it comes to rig sizes and sails. A fine example of a recent collaboration between the two companies is SY Maximus; a mighty 59m German Frers-designed ketch – with a 67.5m mainmast – built by Vitters and delivered in 2023. This is a ship designed to perform under sail: she made her racing debut at the St Barths Bucket in March 2024. “The requirements of this yacht were many,” Vincent Guiot, Southern Spars’ Group Sales Director, recalls. “The rigs had to be safe and reliable yet also one that could be pushed hard around the Bucket regatta course. We also needed a rig that was easy to use whether cruising with the owner and guests onboard, or racing in the big seas off St Barths.”

It is fair to say that a rig capable of taking the loads that a yacht like Maximus generates would have looked very different in the early 90s, when Southern Spars first started out. “Essentially, design tools have become far more sophisticated and accurate,” Guiot reflects. “In addition, the carbon materials used [now have] high modulus and ultra-high modulus fibres, as opposed to standard. The benefit of this is that the fibre is much stiffer, therefore you use less to meet your required inertias.”

Another key factor is that Nitronic steel rod standing rigging has been replaced by carbon fibre. Southern uses ECsix rigging, a carbon technology that is approximately 70 per cent lighter than the Nitronic rod rigging. Given that all that weight is saved aloft, that translates into superior performance, less rolling at anchor and greater strength. “Another vital aspect is the useability of the product,” Guiot says. “Everything is considered [in relation] to how a crew will operate the rig day to day. A rig that is easy to operate will be used more and the operations will be undertaken confidently.”

Maximus carries a crew of 10 and has a simple ketch rig with three ‘working’ sails; headsail, mainsail and mizzen. The ability to easily handle these is key. The development and refinement of in-boom furling has been a significant factor. At the bow, the power and efficiency of headsail furlers has also developed a lot, while push-button technology for all aspects of sail trim means that big sail plans can be handled with much greater ease.

Running rigging has also moved on to deal with the immense loads generated by a giant yacht being sailed hard. Stiffer, stronger fibres are used to enable smaller diameter ropes to be used, while rope covers have been updated over the years to enable light, downwind sails to be trimmed with high-speed winches and not suffer cover burnout.

Then, of course, there are the sails, which on Maximus were developed by Doyle, whose work on Superyachts has garnered great respect in recent years. Although huge sails have been constructed for centuries, the latest generation uses carbon and vectran fibres combined with a composite membrane to be lighter and stiffer. The result is a suit of sails that can be more easily and efficiently handled by a small crew.

Since 2001, Doyle has been developing its own composite membrane sail known as Stratis. This is a sail built in four distinct layers which provides flexibility in fibre orientation, accuracy of placement and superior lamination. “When designing Stratis sails, the first part of the process is to select the surface type,” Mike Sanderson, CEO of Doyle, shares. “Once the surface is laid on the Stratis table, X-Ply yarns are laid to give the sail a base layer of fibre as support before the primary yarns are laid on top. Then once the primary yarn structure is laid into the sail, custom yarn layouts are laid to match internal detailing including internal batten pockets, looping for slides, looping for battens on the leech.”

The whole process then begins again in reverse, with the remaining primary yarn layout being laid before a balance of support yarns, followed by the surface. “Once the sail has all of the fibres laid,” Sanderson continues. “It goes through a lamination process where it is heat-sealed under 16 tonnes of pressure before being finished by the hands of our sailmakers. The result is a stronger, lighter sail that is much smoother when set, and that holds its shape better with significantly less stretch.”

The idea that carbon composites can be good for the environment seems counterintuitive, but the fact that ever larger yachts can be sailed more efficiently with less need to resort to the motor points to a brighter future. The sheer power this latest generation of yachts is able to harness simply with a suit of well-made sails and an immensely strong and efficient rig suggests that perhaps mighty commercial sailing vessels such as Sovereign of the Seas may once more race across our oceans at 20kn, powered by nothing but the pristine, sustainable energy of the wind.