Top-down unfurled!

In the coming days, an impressive fleet of over 170 boats will be tackling the unpredictable and often challenging conditions that will be thrown their way as they head south in this year’s Sydney to Hobart yacht race. This iconic sailing event attracts many yachts, ranging from the fully professional race teams of the super maxis, right down to the Corinthian crews made up of family members, club sailors and friends. Some will be taking on the race to win, while others will simply be happy to participate and experience the thrill of crossing the finish line in Hobart.

There is no question this year’s competitors will all be better prepared to face the challenges coming their way, compared with the generations of sailors that have gone before them. Technological advances in the construction and design of the boats, the sails, electronics, hardware, safety equipment and just about every other aspect of modern ocean racing have contributed to making this race a faster, safer and more enjoyable experience for all competitors.

A significant advance in recent times from a sailor’s perspective is the development of furling systems for downwind sails. This technology owes its origins to the realms of the super maxis and short-handed sailing boats such as the IMOCA 60’s, but it has now trickled down into mainstream sailing to the point where most of the competitors in this year’s race will be utilising the benefits of furling downwind sails.

While the concept of furling a headsail is nothing new, the evolution of top-down furling has revolutionised the art of handling asymmetrical spinnakers and gennakers on modern ocean racing yachts. In the past, the task of dropping a highly loaded asymmetrical sail at night in a heavy seaway, often with a lot of water cascading down the foredeck, was always a risky and challenging “all-hands-on-deck” manoeuver.

These days the same task can be managed in a matter of seconds with minimal amount of crew involvement and virtually no requirement for them to leave the relative safety of the cockpit or make dramatic adjustments in the course being sailed.

There are two main differences between a conventional “bottom up” furling system and the new form of top-down furling: how the sails are attached to the furling hardware and the direction in which the sail furls.

In conventional furling, with sails like code zeros, screechers and staysails, the sails are attached directly to both the furler unit at the bottom, and the head swivel at the top. The structure in the luff of these sails is enough to make the sail turn or roll around itself whenever the furler is active. Due to the sail being directly connected to the furler, the sail begins to furl in an upwards motion, as soon as the furler starts to turn.

With top-down furling systems, using soft luff asymmetrical sails, the head of the spinnaker or gennaker is lashed directly to the top swivel, but the tack of the sail flies independently from the furler unit. The spinnaker tack is attached to a short strop that is connected to a swivel that allows the furler unit to rotate without pulling in the bottom of the spinnaker. The torsion cable then simply transfers the drive from the furler to the top swivel, and this makes the top of the sail start to furl.

As the sail continues to furl, it descends from the head, wrapping tightly around the torsion cable as it goes. This makes for a very tight furl and eliminates the risk of having excess material from the asymmetrical sail’s broad shoulders bagging up unevenly. This bagging can cause the sail to catch a gust of wind and unfurl the sail accidentally at a time when you least want it to unfurl.

The tightness and consistency of a well performed top-down furl is what makes this system so good. It significantly reduces the risks associated with hoisting and dropping spinnakers because you simply raise the sail in the air, firm up the torsion cable to the correct tension and unfurl the sail when you are ready. If conditions deteriorate at any point, you can simply furl the sail up and wait it out. The knowledge that you can get rid of the sail quickly and safely at any time, gives the entire crew greater confidence and peace of mind.

For further details about top-down furling or how to convert your boat and sails to adopt this system, check the furler section of the Ronstan website at or talk to your local sailmaker.

Watch the video here.


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