capnsensible
Well-Known Member
Mainsheet track??
In-mast furling - pros and cons
- Thread starter Magnum
- Start date
Slow_boat
Well-Known Member
I've only used in mast reefing once, on a charter, and was impressed. Until the traveller spewed out its bearings and it wouldn't work at all.
I prefer the KISS principle. Two line slab reefing on my boat means I can reef from the cockpit in under a minute and there's nothing high-tech to go wrong and require high-tech answers and prices.
Though I doubt if anyone buying a new Dufour 45 as a first boat is worried about cost.
I prefer the KISS principle. Two line slab reefing on my boat means I can reef from the cockpit in under a minute and there's nothing high-tech to go wrong and require high-tech answers and prices.
Though I doubt if anyone buying a new Dufour 45 as a first boat is worried about cost.
haydude
Well-Known Member
I have a lot of experience with in-mast furling, in particular Z-Spars and Selden.
With regards to performance, a cruiser or a beginner like your friend will hardly appreciate the difference, but he will most likely enjoy his boat more.
Indeed in-mast main can be smaller, but 10% less sail area does not mean 10% less performance. The loss in performance is hardly appreciable unless the sail and rig are perfectly tuned, which few cruising crews do (when was the last time you tuned your rig?)
Besides in-mast furling mains can have vertical battens!
In any case with in-mast furling I always managed to sail at hull speed pointing at 30deg or less (mainsail without battens).
With regards to jamming I learnt a few things. For the first few years using an in-mast furling I never had a jam, and until that time I never understood what all the fuss was about.
When it happened to me for the first time I could not believe it, I thought I knew all about it and I had a lot of experience, yet it took me sometime to figure out why, and once I did, everything was fine.
It is hard to explain how to avoid a jam because different systems have different quirks, so I will not.
I will just say that if the mainsail has the right shape (not a too loose or too tight halyard) and the furling line has the right size (ropes do swell with time and hence jam!) you will hardly ever get the sail jammed.
With regards to performance, a cruiser or a beginner like your friend will hardly appreciate the difference, but he will most likely enjoy his boat more.
Indeed in-mast main can be smaller, but 10% less sail area does not mean 10% less performance. The loss in performance is hardly appreciable unless the sail and rig are perfectly tuned, which few cruising crews do (when was the last time you tuned your rig?)
Besides in-mast furling mains can have vertical battens!
In any case with in-mast furling I always managed to sail at hull speed pointing at 30deg or less (mainsail without battens).
With regards to jamming I learnt a few things. For the first few years using an in-mast furling I never had a jam, and until that time I never understood what all the fuss was about.
When it happened to me for the first time I could not believe it, I thought I knew all about it and I had a lot of experience, yet it took me sometime to figure out why, and once I did, everything was fine.
It is hard to explain how to avoid a jam because different systems have different quirks, so I will not.
I will just say that if the mainsail has the right shape (not a too loose or too tight halyard) and the furling line has the right size (ropes do swell with time and hence jam!) you will hardly ever get the sail jammed.
Last edited:
Slow_boat
Well-Known Member
I've only used in mast once, on a fortnight charter. It worked a treat until the traveller on the boom shed all its little ball bearings. Then wouldn't work at all.
Being a fully paid up mamber if the KISS club, I prefer the two line slab system I've got on my boat. I can reef from the comfort of my cockpit in less than a minute. There's virtually nothing to go wrong and if it does, I can always just drop the sail or use sail ties to tie clew and tack. It can get a bit unweildy on three reefs, but I try not to get cought out in weather where I'd need three reefs.
Being a fully paid up mamber if the KISS club, I prefer the two line slab system I've got on my boat. I can reef from the comfort of my cockpit in less than a minute. There's virtually nothing to go wrong and if it does, I can always just drop the sail or use sail ties to tie clew and tack. It can get a bit unweildy on three reefs, but I try not to get cought out in weather where I'd need three reefs.
Phoenix of Hamble
Well-Known Member
You appear to have used it twice now Duncan.
Phoenix of Hamble
Well-Known Member
I've had both systems.
One observation..... the two systems are converging....
Slab is getting easier to handle with better cars, reefing systems and stakpacks
In-Mast is getting better shape as sailmakers learn how to cut the sails and new technology is introduced.
Where this will end up, your guess is as good as mine, but what I will add is that I wouldn't choose my next boat on the basis of one or the other.... both would be fine for me.
One observation..... the two systems are converging....
Slab is getting easier to handle with better cars, reefing systems and stakpacks
In-Mast is getting better shape as sailmakers learn how to cut the sails and new technology is introduced.
Where this will end up, your guess is as good as mine, but what I will add is that I wouldn't choose my next boat on the basis of one or the other.... both would be fine for me.
robp
Well-Known Member
I've had in mast furling for 12 years now. There are some things to learn to avoid problems but no great shakes to be honest. I've also got vertical battens on both main and genoa. I don't agree that the entry angle of the batten whilst furling is that critical. In any case the main tends to furl following the sail shape from the luff.
The kit does need some basic service attention from time to time and that should prevent problems. (Checking the drum aloft and lubricating etc.).
With the battens on my Maxiroach's, it is hard to imagine them actually snapping. They'd need a hell of a tight bend to do that, as the material is amazing stuff. Also you can take the sail down with battens inside, it's just not so flexible as without. But in an emergency you can do it. My battens are in one piece. (Beneteau 36, so smaller than the OP mentions).
The kit does need some basic service attention from time to time and that should prevent problems. (Checking the drum aloft and lubricating etc.).
With the battens on my Maxiroach's, it is hard to imagine them actually snapping. They'd need a hell of a tight bend to do that, as the material is amazing stuff. Also you can take the sail down with battens inside, it's just not so flexible as without. But in an emergency you can do it. My battens are in one piece. (Beneteau 36, so smaller than the OP mentions).
Marmalade
Well-Known Member
we've just ordered a new main and have reverted to the manufacturers original spec - no battens for the in-mast furling. The previous owner had installed a battened sail which was great at first but as the years passed got stretched and started to cause problems
Jamesuk
Well-Known Member
Here's a pic of an Oyster 655 with an in-main that does not look too bad.
I helped sail Acheron across the Atlantic leaving just before the ARC last year (2010) funny to see it on here. My old school friend from when I was 10 was the skipper, and my other class mate came along too.
Elemental
Well-Known Member
Maybe, but I don't think those figures alone tell the whole story. the Genoa is 947 sq ft. This means the total sail plan of the two formats is
In-mast furling mainsail 1668 sq ft
Fully-battened mainsail 1797 sq ft
That's a difference of around 7% in total.
If you then consider that in upwind conditions a disproportionate fraction of the power comes from the genoa, then that possibly diminishes the difference still further.
For sure there's a reduction in available power, but other factors such as hull state, hull and sail trim etc can also carry large influence in low wind conditions. The difference attributable to the main sail area may be smaller than you think
haydude
Well-Known Member
A friend of mine is seriously considering buying a new Jeanneau 57. Like myself he's an experienced mobo'er, and he has sailing experience, but this will be his first sailing boat.
He's keen to make his sailing as stress-free and easy as possible so has suggested that the in-mast furling option might be a good idea. I think he could be making a mistake. Here was my response.
"It's an entirely personal matter but I think you might regret going for in-mast furling. Although you quite rightly say you are not concerned about the last 1/2 knot or so it is my understanding that an in-mast furling mainsail offers quite a bit less performance that a conventional sail. The problem with in-mast furling is twofold. Firstly there are no battens, because of course it has to be furled into the mast. This is going to make the sail less stiff and that will affect performance. Secondly, as a result of the lack of battens there can be no roach and this significantly reduces sail area. There's a quick explanation here - http://www.cruisersforum.com/forums/f47/in-mast-furling-15121.html#post161607 . Take a look at the J57 spec and you'll see the standard mainsail is 807 sq ft whereas the in-mast furling mainsail is just 624 sq ft. That's a big difference and something you'll really notice when battling against a few knots of tide. My suggestion is to forego the extra convenience of in-mast furling and go for the slightly less convenient but more efficient slab reefing arrangement."
I would be very grateful for comments on the above
If you gave him such advice knowing that he is not experienced, he is looking at a quite large 57ft and he does not consequently do any racing you cannot possibly be his friend!
You may have shown off your technical knowledge, but you got the priorities totally wrong.
Performance is an extremely secondary issue with in-mast furling, unless you do racing. In very few circumstances somebody not experienced and willing only to cruise will notice any difference, and only in extremely light breeze. In a wind Force above 3 it begins to be hard to notice the real difference.
The advantages of a good system like a Selden (for example) are enormous!
1) it makes the difference between having a good day sailing or staying in the marina when short handed
2) it makes the difference between a scary experience reefing a huge mainsail when it gets blowing or comfortably furling the main from the cockpit, single-handed, having infinite possibilities in reducing the sail size, yet maintaining optimal sail shape.
In cruising boats above 42ft for families or couples is an absolute delight and a must!
Beside, after two boats with in-mast furling and several years sailing I never had a jam. I tried! To see how it could happen, but no, it doesn't. So those who experienced jamming must have had some really dodgy system or quite old and out of shape sails.
Last edited:
GrumpyOldGit
Well-Known Member
haydude
Well-Known Member
Indeed! Modern In-boom even better, but possibly a lot more expensive, although it would really make sense above the 50ft size.
Last edited:
rwoofer
Well-Known Member
Just to show how in-mast furling has progressed here is one on an Oyster 655.
My personal preference having had both is slab reefing, but that is because I have generally moved to boats that perform.
My personal preference having had both is slab reefing, but that is because I have generally moved to boats that perform.
maby
Well-Known Member
Pro : it's very easy when it works
Con : it often doesn't work
Con : it often doesn't work
windpipe
Member
There is never an easy answer to this question and a lot will come down to the type of sailing you want to do. In mast furling can be very reliable, if you are prepared to go with the more expensive versions. Generally the cheaper the boat the cheaper the system and hence more problems.
I like sailing short handed on boats over 45ft so for me it is a no brainer.
I like sailing short handed on boats over 45ft so for me it is a no brainer.
Fluter
New Member
I agree with Windpipe and Haydude. Over 45 feet and certainly at 57 feet, in-mast furling needs to be very seriously considered unless you want to sail with a cast of thousands aboard. In mast in marginal conditions can be faster than fully-battened thanks to the ability to set exactly the right amount of sail for the conditions and so easily. With a fully-battened sail you are often late to take in a reef or shake one out because of the faff.
Climbing up the mast to attach the halyard, flake the sail and fit a boom cover (or even zip up a lazy bag) is not easy on this size of boat. It's likely that you will sail a lot more with an in-mast rig on these larger boats.
Sure, a conventional fully-battened sail is a nicer, more efficient rig but priorities change for larger boats IMHO. If were me, go in-mast and upgrade the sails to spectra or carbon to win back a bit of performance (like the Oyster Acheron).
Climbing up the mast to attach the halyard, flake the sail and fit a boom cover (or even zip up a lazy bag) is not easy on this size of boat. It's likely that you will sail a lot more with an in-mast rig on these larger boats.
Sure, a conventional fully-battened sail is a nicer, more efficient rig but priorities change for larger boats IMHO. If were me, go in-mast and upgrade the sails to spectra or carbon to win back a bit of performance (like the Oyster Acheron).
Dockhead
Well-Known Member
Neither of these statements is true, I'm afraid to say.
That is, it's not all that easy. And - it's extremely reliable.
windpipe
Member
In my experience whenever there is a problem with in mast furling, it almost always comes down to user error. Know how to use the system and understand how it works and you will never look back.
rotrax
Well-Known Member
A friend of mine is seriously considering buying a new Jeanneau 57. Like myself he's an experienced mobo'er, and he has sailing experience, but this will be his first sailing boat.
He's keen to make his sailing as stress-free and easy as possible so has suggested that the in-mast furling option might be a good idea. I think he could be making a mistake. Here was my response.
"It's an entirely personal matter but I think you might regret going for in-mast furling. Although you quite rightly say you are not concerned about the last 1/2 knot or so it is my understanding that an in-mast furling mainsail offers quite a bit less performance that a conventional sail. The problem with in-mast furling is twofold. Firstly there are no battens, because of course it has to be furled into the mast. This is going to make the sail less stiff and that will affect performance. Secondly, as a result of the lack of battens there can be no roach and this significantly reduces sail area. There's a quick explanation here - http://www.cruisersforum.com/forums/f47/in-mast-furling-15121.html#post161607 . Take a look at the J57 spec and you'll see the standard mainsail is 807 sq ft whereas the in-mast furling mainsail is just 624 sq ft. That's a big difference and something you'll really notice when battling against a few knots of tide. My suggestion is to forego the extra convenience of in-mast furling and go for the slightly less convenient but more efficient slab reefing arrangement."
I would be very grateful for comments on the above
The well respected cruising yacht manufacturer Island Packet specify in mast furling as standard on their boats. You can have conventional main and stackpack as an option. Island Packets are often sailed with a husband and wife crew and the in mast main makes perfect sense in those circumstances.
