In mast furling

[Tranona]

Jamming up

should I not like it then I assume I can remove it and go back to slab reefing

however, I also assume that would leave a row of rivet holes up both sides of the mast

will that compromise its structural integrity in any serious way?

D

Jamming is vastly overstated. If the system is properly set up, operated and maintained, just like any other mechanical system, then it is unlikely to jam. Either buy the boat on the basis the system will work in the same way it has in the past for the current owner, or if you are not confident it will, buy a different boat.

 

[eddystone]

Yes, and in addition to the drudgery of having to hoist every time, just consider that although you have roach, which increases the area, the foot of the sail doesn't have a decent shape to give air flow, because it's fastened all the way into the boom. With in-mast it's so easy to tweek the outhaul to get the perfect shape for the conditions.
My commiserations to you.

You can have a slab reefed loose footed sail. Not dissing in-mast reefing but that is not a differentiator.

 

[NormanS]

You can have a slab reefed loose footed sail. Not dissing in-mast reefing but that is not a differentiator.

Of course you can, but Can you show me how you can have a loose-footed in-boom sail? That is what I was responding to.

 

[Dockhead]

I would avoid all retrofitted systems. Had one on a previous boat and it was awful. There are different inherent problems with retrofitted systems including flexing of a mast designed for a normal main, especially on a fractional rig. An in-mast furling mast needs to be very rigid in order to avoid flexing the foil.

I would avoid furling mains on boats under about 40 feet, or maybe 50 feet if most of your sailing is coastal. The advantages become less and less important as the boat gets smaller (and as the sailing gets more coastal), and there is a significant downside in performance and other tradeoffs.

I have a new furling main on my boat this year, made by Sanders out of carbon laminate. Unlike the old one, it has a straight rather than hollow cut leech, held up by short and thin carbon fibre battens. This goes a long way to making up for the performance hit and on my boat, with a Selden furling mast with the wide slot, it works very well. There is certainly no need for leech fluttering or other trim problems just because the main is a furling one. It needs to be cut correctly, like any mainsail, and you need to have proper controls including an effective vang.

The advantages of furling mains in sail handling, and particularly reefing in hard weather, are very great. Another very great advantage of furling mains not much discussed is the ideal storage of the sail when not in use, rolled up smoothly and protected inside the mast. Because of this, furling mainsails typically last longer than regular battened ones, and they are cheaper to begin with, another advantage.

But everything is a tradeoff, and for that you have to pay with less performance, greater windage of the thicker mast, much more weight aloft. You should go into these tradeoffs with open eyes.

 

[Dockhead]

Jamming is vastly overstated. If the system is properly set up, operated and maintained, just like any other mechanical system, then it is unlikely to jam. Either buy the boat on the basis the system will work in the same way it has in the past for the current owner, or if you are not confident it will, buy a different boat.

Indeed.

Furling mains have a number of serious drawbacks, but I do not consider jamming to be one of them. They rarely -- as in "almost never" -- jam if properly setup up and operated. Even maintenance is not that critical.

 

[UncleAlbert]

Well as in most things, wars, F**t*all, Ru??y, tiddlywinks, et al there are two or more sides from which to choose. As this forum shows there are supporters and nay sayers on either side, and long may it so be.

FWIW I like mine for the sailing I do.

So me and my in mast system be it Tab or Bamar or whatever, are very happy. I will however, honestly advise the forum when/if it goes 'orribly wrong.:nonchalance:

 

[JumbleDuck]

Furling mains have a number of serious drawbacks, but I do not consider jamming to be one of them. They rarely -- as in "almost never" -- jam if properly setup up and operated.

That sound suspiciously close to the "No True Scotsman" logical fallacy[1]. The question is not whether ther are liable to jam if properly set up and used; the question is now easy it is unintentionally to set them up or use them improperly. A tightrope, after all, is a perfectly safe way of crossing the Niagara Falls, as long as it is properly set up and used.

[1] No true Scotsman wears anything under the kilt. Any one who does wear something under the kilt is therefore not true Scotsman.

 

[BrianH]

Yes, and in addition to the drudgery of having to hoist every time, just consider that although you have roach, which increases the area, the foot of the sail doesn't have a decent shape to give air flow, because it's fastened all the way into the boom. With in-mast it's so easy to tweek the outhaul to get the perfect shape for the conditions.
My commiserations to you.

Humbly and gratefully accepted.

Of course a loose-footed main is to be preferred, as is the ability to reef further off the wind than I seem to be able to. Everything is a compromise and for me in-boom, on balance, is perceived as superior. That is because my subjective perception puts great store on never risking a jam in the sudden and ferocious winds we can experience in my sailing area.

I know others who know much better than I do, will advise me my fears are groundless, that in-mast reefing rarely jams and only then if wrongly used. But they are my fears and very real to me. Also, I am perfectly capable of wrongly using anything so I prefer to stick to a system where I can always lower the sail in a worst-case scenario.

 

[Dockhead]

That sound suspiciously close to the "No True Scotsman" logical fallacy[1]. The question is not whether ther are liable to jam if properly set up and used; the question is now easy it is unintentionally to set them up or use them improperly. A tightrope, after all, is a perfectly safe way of crossing the Niagara Falls, as long as it is properly set up and used.

[1] No true Scotsman wears anything under the kilt. Any one who does wear something under the kilt is therefore not true Scotsman.

Well, let me say it differently, and speaking from my narrow, personal experience, so make of it what you like. In about 20,000 miles with in-mast furling, I've had two jams. One of them was a bad one. It happened in my very first year of using the system and was the result of an awful combination of bad setup (overtensioned backstay which tweaked the foil) and poor technique (not understanding the right boom angle, not keeping the sail reasonably tight on the foil as it went in).

After that, I had one other jam several years later which was cleared in a couple of seconds.

And that's it. Eventually you get a feel for how it works, and how it goes in and out of the mast, and you understand that it is hardly more problematic than a furling headsail.

The other data point is this -- you will hardly ever find a case of someone who switched to in-mast furling and then switched back. User satisfaction is very high and you will not find many horror stories about jams. You will, however, hear many complaints about performance, weight aloft, etc., which are the real drawbacks of the system.

That being said, if I were buying a boat in the size range of 40 to 45 feet, I would not want in-mast furling. I would want a nice roachy or even flat-top main with full battens, and a ball bearing batten car system and lazy jacks. And a carbon mast. You can't come close to the performance of a setup like that, with an in-mast furling main.

So there's certainly no one right answer to this question, even for one sailor like me.

 

[JumbleDuck]

Well, let me say it differently, and speaking from my narrow, personal experience, so make of it what you like. In about 20,000 miles with in-mast furling, I've had two jams. ....

That's a much better argument!

 

[NormanS]

I'm not sure that actual distance sailed is relevant. For all we're to know, your 20,000 miles might have been two non-stop trips of 10,000 miles each, with the sail furled at the end of each trip. Result 100% jamming, or it may have been 1,000 two mile trips.......

The system works well for me. Indeed very similar to my furling genoa. The main difference being that my wife normally furls the genoa, and I normally handle the main. We do a combined effort with the mizzen in its lazyjacks.

I've never found the need to have the boom at a precise angle. Initially when furling the horizontal angle is determined by the sail, and then the topping lift automatically takes over. With the clew not being rigidly attached to the boom, I fail to see where the horizontal angle of the boom needs to be considered, but maybe I'm doing it all wrong, and am just lucky that it works for me. If not furling when head to wind, I will allow that on mine, it furls marginally better on starboard tack than on port, but that is merely because of the way it winds onto the foil from the slot.

 

[Dockhead]

I'm not sure that actual distance sailed is relevant. For all we're to know, your 20,000 miles might have been two non-stop trips of 10,000 miles each, with the sail furled at the end of each trip. Result 100% jamming, or it may have been 1,000 two mile trips.......

The system works well for me. Indeed very similar to my furling genoa. The main difference being that my wife normally furls the genoa, and I normally handle the main. We do a combined effort with the mizzen in its lazyjacks.

I've never found the need to have the boom at a precise angle. Initially when furling the horizontal angle is determined by the sail, and then the topping lift automatically takes over. With the clew not being rigidly attached to the boom, I fail to see where the horizontal angle of the boom needs to be considered, but maybe I'm doing it all wrong, and am just lucky that it works for me. If not furling when head to wind, I will allow that on mine, it furls marginally better on starboard tack than on port, but that is merely because of the way it winds onto the foil from the slot.

My 20,000 miles were sailed over 7 years, mostly day sails, so in total some thousands of furling and unfurling operations.

Boom angle can be important to get the furl to go on smoothly. The importance of it varies according to the flatness of the sail, height of the clew, etc. My new sail needs the boom to be angled well downward (as seen from the mast); otherwise the sail wrinkles going in which increases the risk of a jam.