Please select your home edition
Edition
upffront 2018 Generic 728x90

Bjarne Lorenzen interviewed: Furling Your Mainsail

by Andy Rice 7 Aug 2019 07:00 UTC
Dacron Coastal Cruising Sail with vertical battens for in-mast furling © Doyle O'leu

Most of the time we think of furling headsails but as Bjarne Lorenzen of sailmaker Doyle O'leu explains, there are options for furling your mainsail too. In the fifth and final post from this series, Bjarne considers the pros and cons of 'in boom' or 'in mast'.

The choice of furling mainsails into the boom or into the mast partly comes down to local preference, says Bjarne Lorenzen. "In Germany we have more in-mast furling than in-boom. In Australia and New Zealand, however, we see more in-boom mainsails being used. It also partly depends on the make of the yachts. For example Bavaria, Hanse and Beneteau all offer in-mast furling mainsails as an option; most don't offer in-boom."

The in-boom option requires less compromise of your ideal sail shape, but it does require the angle of the boom to be precisely located before you start furling away the mainsail. Otherwise the furl will not go smoothly. Despite the challenges, as a sailmaker, Lorenzen tends to be more of a fan of in-boom compared with in-mast. "The sails for the in-mast option are very different. You can do a charter boat with negative roach which is quite ugly - but it's still sailing. You need vertical battens, it doesn't matter whether they are long or short battens, but they tend to be longer than normal horizontal battens. I can't say it's an elegant solution, but it works."

In-mast mainsails are very easy to stow away under most circumstances, which is what makes them so attractive for charter use. However, they're much harder to raise and lower in the first place, which tends to make this a once-a-season exercise. Lorenzen weighs up the pros and cons. "The shape is not as bad as people might believe. With vertical battens we can create a good roach, so the flying shape is not as disadvantaged as you might think. However, the mast is very stiff and you can't bend it much, so you don't have that last bit of control over sail shape like you might on other boats.

"The problems come, though, if you want to reef the sail or if it is damaged, because there is no way of lowering the sail easily with an in-mast system. The luff of the lowered sail is not attached to the mast, so the sail can easily get blown away during the take-down. The lowering of a reefed sail, which is already furled a few rounds, is impossible without the risk of damage."

The other factor to consider is that an in-mast option is a completely integrated rig package. You can't easily retrofit to an in-mast option for your boat without completely changing the mast too. There are some systems to attach furling systems to the backside of the mast, but these are relatively heavy and stop the mast from bending. The manufacturers are keen to keep the additional furling aluminium sections as small as possible which can make it tricky to get the full main sail rolled away in the available space.

In-boom furling avoids many of the compromises of in-mast, says Lorenzen. "Most of the in-boom mainsails are fully-battened, because you need the battens to keep the tension in the foot when you reef the sail into the boom. Also, you can achieve more roach in the sail with horizontal battens, so you don't really need to compromise your ideal flying shape so much." Raising and lowering the sail is straightforward compared with the much greater challenge of in-mast.

The in-boom option doesn't tend to come cheap, however. "In-boom customers are not your average customer; it's more for those aiming for a higher quality - for performance cruising boats, like Luffe yachts, a Swedish performance cruiser with carbon rig for example. In-boom is not going to appeal to the average cruiser with his Bavaria 34. This is for the keen cruising sailor who likes to spend more money on the boat, who appreciates really nice sails. In-boom enables you to trim the mainsail better and bend the mast if you are looking for that little bit of extra performance."

For more information on furling systems, or if you have any queries, feel free to get in touch using our contact form.

Related Articles

Tylaska Cone and Plug Fids explained
How to release loaded fittings remotely Tylaska Marine Hardware is an American manufacturer of high quality- marine hardware for the sailing and marine industry. Tylaska's stated aim is to make the best product based upon physics and not economics. Posted on 16 Jan
Velocitek - get your electronics strapped in
Brackets for every possible mounting point Simple, clear and extremely functional. Velocitek electronics are popular among sailors from beginners to competition veterans thanks to their functional design and ease of use. Upffront are big fans of the Velocitek range of electronics Posted on 8 Jan
Tuff Luff head foils care and maintenance
A guide from upffront.com Tuff Luff's twin-grooved headfoil allows for easy and fast headsail changes. It is a must-have system for any club or competitive race boat. Tuff Luff is owned by Schaefer Marine Inc. who has been in marine hardware design since 1966. Posted on 2 Jan
Soft Attachment Blocks - a guide to the basics
There has been a quiet revolution going on in the last 5 years There has been a quiet revolution going on with block attachments over the last five years. Soft attachments are universally accepted as the preferred method of securing a block. Posted on 25 Dec 2019
Bamar's RLG EVO - Code Zero Furler
Sleek, performance-orientated furling designs investigated Hailing from Northern Italy, Bamar are over 40 years old and on a mission to create sleek, performance-orientated furling designs that aim to 'partially automate sailing operations'. Posted on 19 Dec 2019
Trogear Bowsprits
A good enough reason to drill a hole through your bow Here at Upffront, we talk a lot about asymmetric sails and code zeros, and with good reason! Faster and more manageable, these are a popular choice among many sailors, with one caveat: they require a tack point. Posted on 11 Dec 2019
Loop Woggle is 'The Daddy'
In the world of genoa sheet leads In this blog we look at the trend towards lightweight, flexible sheet lead solutions and why the LOOP Woggle is working its way to the top of the pack in high load situations. Posted on 5 Dec 2019
Andersen Sailing Winches - making the right choice
The key variables and challenges involved in selecting the right winch Andersen winches are a big name in the boating business. Designed and manufactured in Denmark, Andersen Winches have earned a reputation for building high quality, reliable sailing winches that can last a lifetime. Posted on 27 Nov 2019
Calculating your sail areas
When purchasing new hardware this is often a crucial step Lots of equipment on board is load dependant and apart from length and ballast of the boat the primary driver is sail area. It is therefore unsurprising that a lot of hardware manufacturers use sail areas as a primary specification criterion. Posted on 21 Nov 2019
Ino-ending - The end of the line?
Simplicity is key with these blocks When it comes to the Ino-block range, the manufacturer firmly believes that simplicity is key, and Upffront tends to agree with them. Posted on 13 Nov 2019
MBW newsletters (top)