Furling Mainsails

Furling Mainsails

If you want to make mainsail handling as easy as possible, furling is the answer. And that applies whether you have an in-mast system or one that’s fitted behind the mast. A fully-
battened conventional sail with lazyjacks and a Packway will be ideal for many people, but furling provides the ultimate in convenience and control from the cockpit.

Should you decide furling is for you, that is something we will be happy to discuss with you, to ensure you are making the best choice. The most suitable type of sail will be determined by your rig, your budget and your style of sailing. So let’s consider the factors that will influence your choice.

 

WHAT TYPE OF MAST DO YOU HAVE?

If you have an in mast rig by Selden (or Formula, found only on bigger boats), all the opinion are open: You can have a sail with full-length battens, short battens or no battens. On the other hand, masts from most of the French and European manufacturers including Spacraft, Isomat and Z-Spars will give you a more limited choice. The reason is that Selden use a mandrel (the furling spar inside the mast) that is tensioned independently of the halyard and has its own top swivel). This keeps the mandrel tighter, leading to a neater furl and making better use of the space inside the mast.

Other manufacturers’ mandrels are tensioned by the halyard, whose swivel acts as the top bearing. Consequently the mandrel moves around more within the in-mast cavity, leaving less
space for the sail. In addition, Z-Spars have a narrower slot in the back of the mast. What this all means is that unless you have a Selden (or Formula) mast, there will be no room for battens. This will also apply if you have an Easyreef, Tabb, Bamar, the old Reefin’ by Kemp/Selden or our favourite, Facnor.

 

WHAT TYPE OF BATTENS DO YOU WANT?

In recent years, furling mainsails with full-length vertical battens have become increasingly popular. Full battens allow the sail to be built with a roach, whereas sails with no battens have
to have a hollow (concave) leech. The difference can be appreciable, a full-batten sail can be up to 6% larger than a hollow leech alternative whilst minimising any loss in performance
compared with a conventional mainsail. There are buts, however. One is that you can only have full length battens with certain types of mast, as discussed above. This means short battens are a compromise between full-length battens and no battens in terms of performance and price, but you need to check their mast compatibility with us before purchase.

WHAT CLOTHS DO WE USE?

Sails with full-length battens cost more because of the battens, they also cost more because they need to be built from a cloth that is stable, most critically in the leech, to keep the battens
in alignment and rolling in and our the furler smoothly. A stable leech is also needed for both the short battened and battenless furling mainsails.

We believe that the best cloth for furling is Vectron. Due to the mix of polyester and Vectran (a multi-filament yarn spun from liquid crystal polymer), it is a strong, light and durable choice. The alternative to Vectron is a finely woven, high tenacity polyester that uses a minimal amount of stabilising resin. The upgrade to a polyester that uses minimal resin will reduce the breakdown in the stability of your cloth and therefore increase the lifespan of your furling mainsail.

As for the use of laminates in the construction of furling mainsails, many are unsuitable due to the cloths vulnerability to UV damage and that is no good when sun can access the sail through the slot in the back of the mast. Laminates are also prone to mildew built up which can lead to problems when a sail is left rolled up within a confined space and delamination which can increase the risk of chafing when furling and unfurling.

Furling Mainsails

FURLING MAINSAILS

If you want to make mainsail handling as easy as possible, furling is the answer. And that applies whether you have an in-mast system or one that’s fitted behind the mast. A fully-
battened conventional sail with lazyjacks and a Packway will be ideal for many people, but furling provides the ultimate in convenience and control from the cockpit.

Should you decide furling is for you, that is something we will be happy to discuss with you, to ensure you are making the best choice. The most suitable type of sail will be determined by your rig, your budget and your style of sailing. So let’s consider the factors that will influence your choice.

Northern Gypsea

Northern Gypsea

In a post-pandemic, post-graduation daze – we found ourselves window shopping for a more seaworthy vessel than our sleek quarter tonner, an Eygthene 24. Fast forward a month of deliberation and we were the proud new owners of a 1978 Rival 32, which we found by chance, on the Isle of Bute in the Clyde. We were very pleased to inspect the Kemp Sails that came with the boat; a triple reefed, battened mainsail and furling genoa – both in great condition, having hardly been used.

After another month of refitting in the yard, we splashed in August 2020 and got to know our stout new boat alongside the pontoons of Port Bannatyne Marina. We had replaced all standing rigging, fitted a new furling system for the genoa, serviced the engine and added a new electrical system. Our sea-trial was a 150 nautical mile run around the notorious Mull of Kintyre, northwards past the Isle of Jura and into Oban, where we would spend the rest of the season cruising the Inner Hebrides, and then haul out for a bigger refit. Following a fruitful winter of long yard days and modern upgrades, we launched and set sail in May 2021 for the Shetland Isles, the UK’s most northern territory.

The 350 nautical mile passage would take us west through the Sound of Mull, pointing the bow for the Isle of Lewis in the Outer Hebrides. We approached Ardnamurchan point, mainland Britain’s most westerly point, and a gateway to Scotland’s northwest guarded by the towering Stevenson’s lighthouse. Rounding the headland by boat is a rite of passage, shrouded in nautical history and traditionally celebrated by fixing a sprig of white heather to the bow. Depending on the weather and tides here, the sailing conditions can be demanding as the narrow Sound of Mull meets the wide and exposed North Atlantic. These environmental conditions attract vast numbers of cetaceans to the area, with Minke Whales and common dolphins both showing up and accompanying us on passage.

Close-hauled across the Minch, we pressed on through the night to tie up in Stornoway before the arrival of a front. Bioluminescent algae flashed and sparked in our wake as we rode the swell, mimicking the stars overhead. Casting-off from Stornoway gave us enough northerly in our bearing, that it was a straight shot NE passage, rounding Cape Wrath to reach our 60°N destination. We quickly discovered Shetland’s rich cruising grounds, with endless anchorages devoid of other boats. It’s famously windy up here, but provided you have an effective reefing system there’s endless exploring to be done. We have been impressed with our Kemp Sails canvas, the heavy cloth holding up to cold and heavy winds. We regularly sail with a second reef if it’s to be over 20 knots, and the heavily reinforced reef points do a great job in maintaining a flat cut.

Shetland is the perfect launching point for high-latitude cruising, with the Norwegian coast or the Faroe Isles reachable within two days sailing. Naturally we began seeking distant horizons, and the early winds of June 2022 favoured a trip to the fjords of Norway. Broad-reaching across the North Sea in a SW F6, we realised the true potential of our Rival as a bluewater cruiser. The heavy displacement and swept bow make for an easy motion in a seaway, and a relatively dry deck.

We made landfall in Bergen after a respectful 36-hour crossing, and after catching up on sleep, made our way into the endless network of fjords that connect this nautical nation. Again, we had most anchorages to ourselves, and we explored by hiking, swimming and fishing from the boat. The deep and fast flowing, steep sided fjords conform to produce exciting training grounds with constant attention required to the wind direction. One drastic wind shift saw us douse the asymmetric spinnaker and haul the boom up for a close-hauled beat with no change to the compass bearing!

By a stroke of luck on our return trip to Shetland, a SE F6 was forecast and we enjoyed similar conditions to our trip over, averaging speeds of 7 knots at points. We snuck past towering oil rigs and made landfall on Shetland in thick, summer fog – after 39 hours at sea. Our season was far from over yet though, and in July we cast off for a dream destination in the North; Fair Isle. Famous amongst long-distant cruisers, Fair Isle is like the Azores of the North, offering respite to boats on eastern and western passages. We encountered some lively seas on our way down, as the strong south-going tide converged with big westerly swells. North Haven on Fair Isle provided us with welcome shelter in amongst boats on transit to Faroe and Norway, and we met an eclectic bunch of like-minded folks from France, Norway, Ireland, Faroe, Alaska and Scotland.

Sailing to Papa Stour in September was a polar opposite experience, as we had the remote island almost to ourselves – except the shirtless crofters on quad bikes and giant grey seals we shared the anchorage with. As Autumn arrived, we got out in heavier weather as much as we could, testing our newly installed inner forestay with a scrap of hanked-on jib. Since stepping the mast in December, we’ve hunkered down and kept the stove going aboard – planning for 2023’s adventure and installing safety gear. Our first destination in the spring is Lofoten, in Arctic Norway!

The Start of our Journey by Teulu Tribe

The Start of our Journey by Teulu Tribe

First of all, hello! We are Becka and Zach, a couple who saved with all their might for three years whilst living in Swansea, Wales, to finally buy their 1987 Colvic Victor 40 sailboat. Upon buying our boat, named Teulu (it’s a Welsh word- pronounced Tay-lee), we bunkered down in Plymouth in order to get her up to a liveaboard, around the world standard vessel.

They say that if you wait until your boat is 100% ready, you will never leave, and as we neared our departure date back in September, we felt that through and through. Our mizzen mast had only just been craned back on, solar panels, batteries, VHF aerials fitted and life raft back from service. That week was all go! But, on that day, we let the lines off and as we sailed out of the Plymouth sound, all the angst, worry and doubt of our readiness just drifted away with the swell passing under our hull.

It’s a pretty long story but the first trip out of Plymouth stayed just that, a trip out of Plymouth and back into a cosy anchorage in the Helford River near Falmouth. We were novices in weather planning and unfortunately for us, the gale that hit the Scillies head on, also hit us dead on the bow. Think breaking waves at all angles and 32 knots of wind. It wasn’t ideal, so turning back was the best decision for us in that moment. A few weeks later, with fresh minds and after a tonne of planning this time, we set off on our passage across the English Channel. The next morning, we arrived (actually too early!) at the entrance to the Channel du Four. This stretch of water was renowned for its multiple rocks, gushing currents and countless navigational markers so required meticulous planning and a good set of binoculars! A couple of hours later, we had flown down the channel, hitting 10 knots at times (the tide was 5 knots- but we will ignore that!). We cruised into Brest feeling incredibly proud that we had accomplished that section of water

However, it was a ‘no rest for the wicked’ moment, as after a trip to the customs office and a good nights sleep, we cracked on with boat jobs. On the channel crossing, we had noticed a section of wear in our port side genoa sheet so we hired some bikes and cycled to the chandlery to buy a new one and then popped to a supermarket to resupply our cupboards. A quick stop at the marina office to use their WIFI to check the weather, changed all of our plans as there was a gap in the weather to cross the Bay of Biscay.

However, we had to be quick as a large system was rolling in. ‘We leave today at 3pm’ we exclaimed, suddenly rather flustered at the prospect of leaving again after just arriving less than 24 hours prior! But, after finishing all our jobs and having a coffee (or two), we let go of the marina lines in Brest and set out on the first section of the Bay of Biscay crossing- the Raz du Sein.
This was a similar stretch of water to Channel du Four with the number of cardinal markers (these mark danger), rocks and extreme currents. But, having now had a ‘practice’ section the day before, we felt dab hands at it and we sailed happily down the fast section of water between the mainland and the tiny Ile de Sein island.

The first night was beautiful. We had a full moon, our whisker pole was out and our Kemp sails were full. There was a steady 15 knots of wind with small rolling waves. We read our books, listened to podcasts and by the time we knew it, it was the morning.

On this day, the weather picked up a little and the wind went from 15 knots, to 25 knots by 8pm in the evening. We reefed early, just after dinner and prepared ourselves, and Teulu, for the rolly night. With 1.7m waves every 6.8 seconds, our autopilot was struggling to keep up and we ended up hand steering a good amount of the night. Combined with the sound of our free-spinning prop (we have a hydraulic gearbox so this is our norm) it was hard to switch off and get any rest. A combination of seeing other boats fly along at 20 knots and the wind shifting resulting in us having to change course and head more towards Santander, it was a rather intense night and I think Zach would agree that we were both relieved to see the sun rise the following morning.

The sun showing its face and the water transforming from a medium grey to a rich blue, lifted our spirits and around 7pm the following day, we spotted land. Although the crossing had not been long, nor too strenuous, it was the most surreal and fulfilling moment when we realised we had successfully sailed our own boat from France to Spain, across one of the most dangerous sections of water in the world.

However, we weren’t out of the woods yet. When we were 20 miles offshore, with the glimmer of lights guiding us in, the weather took a turn for the worse. We had heard the gusts really pick up along the Northern Spanish coast so we reefed early but we were still incredibly heeled over when they hit. The seas were confused and we were being flung about as we approached Gijón. The heavy rain bought a lot of haze and turning into wind to drop our sails, felt like we were participating in a rodeo! However, with the motor on, we passed through the breakwater into the marina and tied the lines on.

Accompanied by loud music from a nearby nightclub, Zach and I stood on the pontoon, in awe (or shock?) that we had another 300 miles under our belt and a new country to explore.

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Downwind Update

Downwind Update

Much has changed with downwind sails over the past 15 years or so. For cruising sailors it used to be a relatively simple choice between a spinnaker flown from a pole and a cruising chute tacked to the stemhead (or to a short bowsprit). Now there’s an array of lightweight asymmetric sails including, of course, the one everyone talks about: the Code 0 (though many sails described as Code 0s are really not Code 0s at all, as we will explain).

So what has happened, why has it happened and, most importantly, where does it leave you?

G-One on a Discovery 55 (Kemp Sails)
Photo: G-One on a Discovery 55 (Kemp Sails)

WHERE RACING LEADS…

As developments in cruising so often do, it all started with racing boats. About 20 years ago in the Whitbread (subsequently Volvo) race we witnessed the appearance of the Code 0: a large, lightweight, free-flying headsail rather like a flat-cut asymmetric spinnaker. It was designed to fill the gap between a conventional spinnaker and an upwind headsail – not so much a downwind sail as what you might call a “crosswind” sail.

These sails and their variants have since become popular across the racing world and in cruising circles too. Just bear in mind that many so-called Code 0s are not actually Code 0s because, under the IRC rating rule, a Code 0 has to have a mid-girth that’s 75% of its foot measurement. In practice that means a rounded luff that’s typically not attached to the torque rope of a furling system. Such a sail is more of a challenge to handle than many cruising sailors want.

There has, however, been an increasing need for cruising sails that fill the gap between upwind headsails and conventional spinnakers, and that’s largely because of changes in modern rigs. Back in the days of the IOR (international offshore rule, which influenced cruisers as well as racing yachts), boats tended to have relatively small mainsails and large foretriangles with overlapping genoas. More recently, for easier handling and inspired by racing rules since the end of the IOR, we have seen a move towards larger mainsails and smaller fore-triangles. Self-tacking headsails have become increasingly popular, too.

These changes have simplified handling, particularly upwind when much less winching is called for, but they have led to a problem. When you bear away from a close-hauled course and ease a small, close sheeting headsail, it twists open and loses most of its drive as well as progressively disappearing behind the mainsail. In light winds you will often be slower on a reach than upwind, yet unable to hoist a spinnaker or cruising chute until the wind is approaching, or abaft, the beam. This leaves a wide angle between a fetch and a broad reach when many modern cruisers feel rather lifeless. So what’s the answer?

MULTIPLE CHOICES…

Fundamentally the choices are the same as always: symmetrical and/or asymmetrical. It’s just that there’s now a far greater range of asymmetrics (sometimes known as A-Sails) to choose from, ranging from those that are essentially large, lightweight genoas all the way to full-cut asymmetrics for deep downwind angles. As you would expect, at Kemp we offer sails to cover the whole spectrum and we’ve given a lot of thought to what each sail should be designed to achieve. Even with all our expertise and experience, however, we have yet to come up with one sail that does everything. We will announce it as soon as we have changed some of the laws of physics! In the meantime, read on to see how we can make your downwind sailing fast, fun and trouble-free.

DOWNWIND AND CROSSWIND OPTIONS…

In ascending order of wind angle – from close to broad – below are the sails to choose from. But before we introduce them, a word about furling systems, which are often used to make handling these sails as simple as possible. Furling systems using torque ropes (otherwise known as anti-torsion cables)have played an essential role in making lightweight, free-flying asymmetric sails manageable by short-handed crews.

In many respects they’re like conventional furling systems for headsails, only they’re not connected to the forestay and, instead of an aluminium extrusion between the bottom drum and the top swivel, there’s a torque rope. When you turn the drum, the torque rope turns like a headfoil, without twisting, and the sail wraps around it. Another difference is that some of these downwind sails are not attached to the torque rope – just the tack to the drum and the head to the top swivel. There are also two types of furler: bottom-up and top-down, depending on whether a particular sail should be furled from the tack or the head. We supply both types as appropriate and, importantly, many components are common to both, so if you have multiple sails you won’t need to buy two complete furling systems.

Photo: Racing Asymmetric – A2 (Team Firefly)

1 | ULG
Usually made from 3oz polyester (as opposed to spinnaker nylon), the ULG has a straight luff and can be handled with a bottom-up furler or without any handling aids. It’s ideal when you’re cracked off the wind a few degrees and want to keep the boat powered up.

2. G-ZERO (GENNAKER)
Our G-Zero is similar to the ULG, also with a straight luff and the torque rope encapsulated in a luff sleeve for easy handling. Being designed for slightly broader angles, it’s made from nylon rather than polyester and incorporates more roach in the leech. Suitable for use with a bottom-up furler or a snuffer (or nothing at all if you prefer).

3 | G-ONE (CRUISING CHUTE)
This is the closest equivalent to what has commonly been known as a cruising chute and will help keep the boat moving as the wind comes further abaft the beam. Fuller cut than G-Zero, it’s made from spinnaker nylon and, if you have a furling system (top-down for this one), the luff won’t be attached to the torque rope. There’s also some round (positive roach) in the luff. A snuffer is an alternative handling aid with this sail.

4 | RACING ASYMMETRICS (A0–A5)
For racing sailors we offer the full range of racing asymmetrics, from the Code 0 (A0) to specialised reaching and running sails. Please ask for details.

5 | THE BUTTERFLY SAIL
With this option you have two sails in one. It consists of two ULGs sharing a luff rope. Use them folded together in the same way as a ULG or, with the wind from astern, spread your wings and open them up one each side. If you pole the windward one out, you can sail with the wind up to 15° off dead astern. Use with a bottom-up furler.

6 | SYMMETRIC SPINNAKERS
We’re listing this as a single option but, of course, there’s a whole host of choices for different wind strengths and points of sailing. These sails are still the most efficient solution for sailing deep downwind and running square, but they do call for a pole and a little more experience.
All downwind sails are a compromise and, as you can see, there’s quite a choice. ULGs and G-Zeros are the easiest to handle. If you’re going to have just one sail, we would suggest a G-Zero or a G-One. If your budget allows two, a ULG and a G-One would be a good combination. Bear in mind that, depending on conditions and how well they’re furled, you will often be able to hoist a ULG, G-Zero or G-One and leave it up for a day’s sailing with no need to drop and re-hoist each time you use it (though do bear in mind the greater susceptibility to UV degradation of these thinner fabrics).

AND FINALLY, LET’S NOT FORGET…

The magic, all-in-one downwind sail that does everything brilliantly. When we’ve invented this, we will supply it in a package with a dozen sky hooks to hang things from – and that’s a promise!