Would I regret buying an old boat with in mast furling?

[dom]

As others have observed furling mains they are easier to reef and much easier to stow at the end of the day. It is also true that furling mains allow an infinitely variable amount of sailcloth to be set, which is the point two common misconceptions set in:

1. Furling mains can be more accurately set to prevailing wind conditions than regular mains: this is simply not true. Furling mainsails are inherently difficult to build and the lack of a conventional batten structure alongside the flatness of cut (required to to enable furling) necessitates compromises to both size and shape of the sail. For example, it is not really possible to control a furling main via mast bend (too flat), it is hard to constrain the centre of effort to where one wants it, and it is almost impossible to balance forward-drive against healing force as the wind rises. Without battens there is no structure to resist leech compression, which consequently causes the leech to creeping forwards towards the luff under load. This causes the sail to get fuller, the last thing one wants when the wind is forward of the beam. This is the point a regular fractionally rigged boat will be flattening his main by tightening the backstay, flattening the outhaul and winding in the Cunningham to max.
2. Vertical battens can sort out the problem: the obvious drawbacks of vertical battens are chafe and difficulty of getting the sail down in an emergency (never to be underestimated as sails sometimes blow!). Apart from easily getting the sail down, all of these problems can be addressed by good engineering. But other difficulties persist; whilst vertical battens can allow a little bit of roach and somewhat resist leech-creep, they cannot address the chord compression loads that cause a sail to get fuller under load. They are therefore only a partial solution. One could improve upon this by adding some ultra-high modulus laminate sailcloth into the equation, but that gets price and cruising laminates are bulky as they require a taffeta layer on both sides of the sail.

My point is simply that the mainsail is an integral part a boat’s aerofoil which is controllable in more dimensions than any other sail. In mast systems have a lot going for them in terms of convenience, but they also have some serious drawbacks, and one needs to strike one’s own personal balance between the two.

 

[ip485]

Dom - my rig is relatively primitive as the mast is really not designed to bend! However I do find winding on the outhaul has a pronounced effect on flattening the main - as you would expect - and there is enough travel left on the boom even when fully unfurled. Its not perfect of course but it cerainly aids driving up wind.

As I mentioned before the full length battens make a world of difference to the shape. I have seen both flat and round battens. Mine are round and seem preferable with no sign of wear so far. Should the need arise the battens can be relatively easily dumped out of the foot and fall pretty much under their own weight even under some load. They screw together in sections which is also a great help.

My main was made by Kemp who have constructed a very good shape.

I agree they are a compromise but given the size and usually a crew of two I would hesitate to go back to a conventional main given that on watch it is easily manageable with one person (without having to disturb the other from getting some sleep). We also race a little and again this is a joy with just a crew of two on a 50 foot yacht, albeit some big powerful electric winches make a hell of a difference.

I think the advantages diminish as the yacht becomes smaller because sail handling becomes a lot easier and perhaps performance more critical. After all we will make way to wind at a reasonable speed with some wind because of our waterline lenght without milking every bit of energy out he sails.

I know, big boats make you lazy - perhaps.

 

[NealB]

Great thread: loads of useful knowledge there, and some good stories.

Please don't be shy to share more.

Thank you!

 

[dom]

Please don't be shy to share more.

Hmm, well if you're still unsure about whether you like Marmite or not, you should probably taste it yourself before getting the dosh out of your pocket. After all it's not easy to scrape off once it's spread all over your toast! Then again if you love it why miss out :ambivalence:.

 

[NealB]

Hmm, well if you're still unsure about whether you like Marmite or not, you should probably taste it yourself before getting the dosh out of your pocket. After all it's not easy to scrape off once it's spread all over your toast! Then again if you love it why miss out :ambivalence:.

Excellent advice, thank you (nothing like a good analogy)!

Someone who knows a thing or two about such matters, has suggested another possible alternative.

Apparently, some in-mast furlers can be removed, and a track fitted in its place to take slides/ batten fittings. Anyone come across this?

 

[Javelin]

Not really going to add much to the discussion other than to say I've had to fix far more issues with in-mast furling than I've had to fix conventional systems.
Off the top of my head in terms of number of issues,
In boom furling is the worse, followed by old round boom furling systems, then in-mast systems, fully battened which is usually compression car related and then conventional.
Like most labour saving devices they are superb when working but a nightmare when they're not especially if there is no alternative backup.

One other factor is the bigger the boat the more likely you have have to use a winch or worse, an electric winch.
Unsympathetic use of winches possibly accounts for the majority of rig damage that I've seen in the yard and this also applies to Jib furler systems.

 

[NealB]

Only you will know but given that you are asking the question it is not a good sign.

As the others have observed, it is a great option for the aging sailor who wants to prolong sailing with a bigger boat. Like many aids to easy sailing, they all tend to hack away at the performance of a boat and in the end you find you have re-invented the Motor Sailor. Fine if that is what you require.

Ask yourself truthfully if you found another indentical boat with conventional arrangements which one would you buy? That may give you a steer.

You make some points that really strike a chord ..... thanks!

Without any doubt, if she had a conventional rig, my offer would be in by now.

 

[mjcoon]

Great thread: loads of useful knowledge there, and some good stories.

Please don't be shy to share more.

Thank you!

OK, I don't think anyone has mentioned the two ways of spinning the foil. I think the simpler and less problematic is a spiral groove in the foil below the sail which takes the furling line. Then you only have to note which is the furling line and which the outhaul. Keeping a bit of tension on the one that is not being pulled is just the same as for a furling genoa. It is of course more crucial to wind into the spiral than into a genoa furling drum.

The worse system to my mind (which we had on a charter yacht last September) is a winch on the mast which is geared to the foil and takes a continuous furling line. It also has, as someone mentioned, a ratchet/free-run switch on the drum which necessitates a trip to the mast to switch over. We found it quite tricky to keep appropriate tension on all three bits of string that come back to the cockpit.

Mike.

 

[Tranona]

OK, I don't think anyone has mentioned the two ways of spinning the foil. I think the simpler and less problematic is a spiral groove in the foil below the sail which takes the furling line. Then you only have to note which is the furling line and which the outhaul. Keeping a bit of tension on the one that is not being pulled is just the same as for a furling genoa. It is of course more crucial to wind into the spiral than into a genoa furling drum.

The worse system to my mind (which we had on a charter yacht last September) is a winch on the mast which is geared to the foil and takes a continuous furling line. It also has, as someone mentioned, a ratchet/free-run switch on the drum which necessitates a trip to the mast to switch over. We found it quite tricky to keep appropriate tension on all three bits of string that come back to the cockpit.

Mike.

Not sure why you had a problem with the Selden geared system - which is the most common system available and is replacing the other types on many new boats. It is really not necessary to use the ratchet at the mast. I have had 2 of these systems and never any difficulty controlling the furling and outhaul from the cockpit. Just control the furling line with the clutches. I have mine set up with the outhaul to port and the furling line to starboard so that I can control the sail standing in the middle of the boat. With a bigger boat or if using a crew I would probably rig both on the same side. However for my relatively small boat and singlehanded I find my set up works well.

 

[l'escargot]

Not sure why you had a problem with the Selden geared system - which is the most common system available and is replacing the other types on many new boats. It is really not necessary to use the ratchet at the mast. I have had 2 of these systems and never any difficulty controlling the furling and outhaul from the cockpit. Just control the furling line with the clutches. I have mine set up with the outhaul to port and the furling line to starboard so that I can control the sail standing in the middle of the boat. With a bigger boat or if using a crew I would probably rig both on the same side. However for my relatively small boat and singlehanded I find my set up works well.

I have mine the same. The only time I've ever used the ratchet lock is in the winter to lock the sail, in the unlikely event that it worked out in high winds.

 

[NormanS]

I have the same, and have never had need to use the winch or the ratchet. I find the system works faultlessly, and would never go back to having to hoist the mainsail whenever it's needed. It does explain the number of boats that you see motoring with the main still hoisted.

 

[Lucky Duck]

I seen more than enough boats with in mast furling motoring into the wind with the main sail flogging to death, I'd assumed they wanted a new mainsail.

 

[BrianH]

Off the top of my head in terms of number of issues,
In boom furling is the worse, followed by old round boom furling systems, then in-mast systems, fully battened which is usually compression car related and then conventional.

As a satisfied in-boom reefing owner I'm intrigued by your list of problematic mainsail furling systems. True I had a lot of teething problems but the advantages of full-length battens and the ability to always drop the mainsail in a rising gale, whatever happens to the furling mechanism, made it my choice. Care to elaborate on what exactly causes the principle to be top of your list?

 

[Javelin]

The issue with in boom is getting the relative angle between the boom and mast just right.
When its works I think I would prefer the system to in mast for a number of reasons, however;
If the angle is not right the sail either walks aft or forwards during the roll which then jams.
On two of the booms I had to fix the plastic control line fairleads were simply not man enough, failed and jammed.
On another the rod kicker would push the boom up too high so the sail walked aft jamming and ruining the leach so the kicker would have to be set just right to get it to work.
This was on a 50' and the cost of the damage done when someone inadvertently adjusted the kicker before furling the main was eye watering.
On another all was fine unless it was blowing f5 or more and then the boom would shake causing an uneven roll.
On another you had to release most of the back stay tension and get the mast dead straight before a drop.

All these were on 35' or above yachts, my guess is the problem is reduced as the sail size drops.

 

[BrianH]

Thanks for that and I can understand the problems, having had a long learning curve in the early days getting the mast-boom angle just right. Heaven help anyone who ever touches the adjustment nuts on the boom strut now ...

And with my 31 footer, I can agree that small is probably easier - although getting that last few meters of luff to the top of the articulating slot is a bit of a bind. But when it is eventually and properly set up it works like a dream, I wouldn't go back to any of my previous systems ... not that I've owned in-mast but have some fair amount of experience with other peoples' boats.

 

[Tranona]

As others have observed furling mains they are easier to reef and much easier to stow at the end of the day. It is also true that furling mains allow an infinitely variable amount of sailcloth to be set, which is the point two common misconceptions set in:

1. Furling mains can be more accurately set to prevailing wind conditions than regular mains: this is simply not true. Furling mainsails are inherently difficult to build and the lack of a conventional batten structure alongside the flatness of cut (required to to enable furling) necessitates compromises to both size and shape of the sail. For example, it is not really possible to control a furling main via mast bend (too flat), it is hard to constrain the centre of effort to where one wants it, and it is almost impossible to balance forward-drive against healing force as the wind rises. Without battens there is no structure to resist leech compression, which consequently causes the leech to creeping forwards towards the luff under load. This causes the sail to get fuller, the last thing one wants when the wind is forward of the beam. This is the point a regular fractionally rigged boat will be flattening his main by tightening the backstay, flattening the outhaul and winding in the Cunningham to max.
2. Vertical battens can sort out the problem: the obvious drawbacks of vertical battens are chafe and difficulty of getting the sail down in an emergency (never to be underestimated as sails sometimes blow!). Apart from easily getting the sail down, all of these problems can be addressed by good engineering. But other difficulties persist; whilst vertical battens can allow a little bit of roach and somewhat resist leech-creep, they cannot address the chord compression loads that cause a sail to get fuller under load. They are therefore only a partial solution. One could improve upon this by adding some ultra-high modulus laminate sailcloth into the equation, but that gets price and cruising laminates are bulky as they require a taffeta layer on both sides of the sail.

My point is simply that the mainsail is an integral part a boat’s aerofoil which is controllable in more dimensions than any other sail. In mast systems have a lot going for them in terms of convenience, but they also have some serious drawbacks, and one needs to strike one’s own personal balance between the two.

While your description of what can be done with a sail if you have the controls to do it, once you have decided to go in mast that is mostly irrelevant as the controls (nor a sail that can be manipulated) are no longer available. As you say you simply cannot shape the sail other than alter the size and the draft.

However, this is not the point. First the benefits of manipulation are not necessarily of interest to a cruising sailor in just the same way as what Lewis hamilton can do to the set up of his F1 car is of little relevance to road car users. If you have a boat that responds to such changes then without them the boat is a bit wasted. If, however, you have a well laden cruising boat then such fine tuning probably does little to enhance the use of the boat. The key thing apart from ease of handling of in mast is the infinite variability of sail area (particularly combined with furling headsail) rather than shape. Newer designs have moved away from large headsails that are a hangover from IOR days and now have the majority of sail area in the main. So adjustment of sail area in the main is the tool for balancing the boat to reduce steering loads and sail efficiently.

Slab reefing limits you to fixed mainsail sizes and lots of fine adjustments to balance the boat. This can be very limiting for cruising sailors in boats that do not respond to such antics. This perhaps explains part of the reason why in mast (and to an extent in boom) furling dominates the larger cruising boat market.

The key thing in buying an older boat with in mast (once you have accepted the principle) is ensuring that the gear works properly and has been well maintained. Poorly functioning gear can make it a very negative experience and sorting it probably not easy if the problems are mechanical.

 

[dom]

While your description of what can be done with a sail if you have the controls to do it, once you have decided to go in mast that is mostly irrelevant as the controls (nor a sail that can be manipulated) are no longer available. As you say you simply cannot shape the sail other than alter the size and the draft.

However, this is not the point. First the benefits of manipulation are not necessarily of interest to a cruising sailor in just the same way as what Lewis hamilton can do to the set up of his F1 car is of little relevance to road car users. If you have a boat that responds to such changes then without them the boat is a bit wasted. If, however, you have a well laden cruising boat then such fine tuning probably does little to enhance the use of the boat. The key thing apart from ease of handling of in mast is the infinite variability of sail area (particularly combined with furling headsail) rather than shape. Newer designs have moved away from large headsails that are a hangover from IOR days and now have the majority of sail area in the main. So adjustment of sail area in the main is the tool for balancing the boat to reduce steering loads and sail efficiently.

Slab reefing limits you to fixed mainsail sizes and lots of fine adjustments to balance the boat. This can be very limiting for cruising sailors in boats that do not respond to such antics. This perhaps explains part of the reason why in mast (and to an extent in boom) furling dominates the larger cruising boat market.

The key thing in buying an older boat with in mast (once you have accepted the principle) is ensuring that the gear works properly and has been well maintained. Poorly functioning gear can make it a very negative experience and sorting it probably not easy if the problems are mechanical.

All fair points and I'm loving the expression, "boats that do not respond to such antics"!

I think most of us agree that at the end of the day it boils down to a compromise and I can certainly see the advantages of a furling main. There as however a vast spectrum between a slow old tub and an America's Cup yacht and I personally think many cruising sailors are unaware of how much better their boat might sail with first class sails and without the cruisy junk. Perhaps some are not interested, perhaps some are; either way it's good to know what the choices are.

 

[Tranona]

All fair points and I'm loving the expression, "boats that do not respond to such antics"!

I think most of us agree that at the end of the day it boils down to a compromise and I can certainly see the advantages of a furling main. There as however a vast spectrum between a slow old tub and an America's Cup yacht and I personally think many cruising sailors are unaware of how much better their boat might sail with first class sails and without the cruisy junk. Perhaps some are not interested, perhaps some are; either way it's good to know what the choices are.

But once you have made the choice of in mast then most of what you talk about is not available. Suggest it is not through ignorance that the choice is made - most people buying the sort of cruising boats we are talking about probably have experience and understand what it is possible to do with sails, but make a conscious choice based on their needs.

As is obvious from the many threads on this subject, very few regret that choice. Perhaps you should put yourself in the shoes of others and appreciate why they hold that view.

 

[dom]

But once you have made the choice of in mast then most of what you talk about is not available. Suggest it is not through ignorance that the choice is made - most people buying the sort of cruising boats we are talking about probably have experience and understand what it is possible to do with sails, but make a conscious choice based on their needs.

As is obvious from the many threads on this subject, very few regret that choice. Perhaps you should put yourself in the shoes of others and appreciate why they hold that view.

You're right, one is indeed locked-in once that particular choice is made, which is I guess why the OP asked the question he did.

Incidentally I never used the word "ignorant", I said "unaware". I am unaware of most things on this planet, but I don't think that makes me ignorant. But you're right, it's always a good idea to put oneself in other people's shoes and perhaps at one of next year's get togethers it might be a good idea for peeps to have a go on other people's boats. Could be fun!

 

[Tranona]

You're right, one is indeed locked-in once that particular choice is made, which is I guess why the OP asked the question he did.

Incidentally I never used the word "ignorant", I said "unaware". I am unaware of most things on this planet, but I don't think that makes me ignorant. But you're right, it's always a good idea to put oneself in other people's shoes and perhaps at one of next year's get togethers it might be a good idea for peeps to have a go on other people's boats. Could be fun!

Point taken about the use of the word ignorant. However I was fully aware of the arguments in favour of alternatives when I made the decision to have in mast - along with just about all the mature serial boat owning buyers of the same boat that I eventually bought.