In mast furling vs slab reefing

[Anonymous]

We are planning to buy a 43-45' cruising boat such as the Jeanneau 43DS and one of the key requirements I have listed is in-mast furling. There is only my wife and myself, and my wife doesn't really sail, anyway, so I have to be able to do everything single-handed in all weathers. For this reason I decided that in-mast furling was essential. However, I've never had slab-reefing led back to the cockpit and I've never had in-mast furling, either. I've always had to clamber on deck to the mast.

A couple of nice fairly new boats have appeared for sale with slab rather than in-mast. Should I consider them? The specs are such that it seems likely that the owner preferred slab. Any advice welcomed, please.

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[Robin]

I am not a fan of in-mast reefing, the loss of sail area is very destructive to light wind performance and there is always the risk of it jamming.

In my view it is perfectly possible to design a slab reefing system with all the lines taken back to the cockpit such that reefing is easy and safe, whilst retaining the ability to have a 'proper' sail shape and with no loss of area. On our 41' Jeanneau Sun Legende we have a fully battened mainsail with 3 reefs and lazy-jacks. All 3 reefs, with separate lines for tack & clew reefs, are taken back via clutches to self-tailing winches mounted on the coachroof under the sprayhood. There is no need for anyone to go on deck to put in or take out a reef and the system is quick and easy to use single-handed.

Remember that for long term, long distance cruising, especially if loaded with live-aboard gear, the ability to sail in light winds is very important, you will meet many more light wind days than storm days unless you propose visiting extreme places.

All IMHO of course, many people like in-mast I know, it is just not for me.

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[mike_bryon]

I agree with everything said about the advantages of slab reefing. I crewed a boat from Crete to the UK with in mast reefing and while it was an old system it was not only inefficient but at times also quite dangerous. In strong weather the reefing line tended to slip while you were reefing and you found you had more not less sail out! no doubt more modern systems avoid this issue but it left a bad taste.

When short handed I prefer an autohelm and use heavy preventors then you can go forward and reef especially with a nice big deck belonging to a boat of around 45 feet. I have found the main drop systems that work on the slab reefing very good.

I would view the boats with slab reefing and suggest you do not reject them for that reason alone.




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[ChrisE]

I'd endorse what Robin has said but for different reasons. We have slab reefing and have deliberately not had lines led back. Sooner or later, you will have to go forward at sea to sort out a foul up. We beleive that with having to go up to reef we keep the skill and in the long term will benefit us.

I say this as one who has poor balance and has to hang on for grim death in anything above a f3. I clip on and hang on to what ever I can or in extrfemis do the whole thing on my backside. Not elegant but it works.

The other item to consider is the KISS (1) principle. If your in-mast jams in or our then you have no main either because its stuck in or shredded in the wind.

Keep It Simple, Stupid

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[Robin]

Trouble is I'd then have to put on the oilies, then the harness and the slippers would have to go too!

Joking apart, for us we have everything back for reefing in one spot, it can then be done by just one person. IMO it is all or nothing, if you have to go forward to hook on a reef, or for the halyard it is better to do the whole job at the mast. Our procedure with every bit led back under the sprayhood is:-

Let go mainsheet
Let go kicker (ours is rigid and supports the boom, no need for topping lift)
Let main halyard down to a premarked position
Pull in reef tack line through clutch, close clutch (winch available but not needed)
Winch in reef clew line through clutch
Re-tighten main halyard
Tension kicker
Re-set mainsheet
Take up loose slack on next reef lines
Drink coffee.

The loose sail sits in the lazyjacks.

We once tried a Westerly Oceanlord with in-mast and the sail would not unfurl, the leech jammed in the slot, probably because the sail was knackered but it didn't help my prejudice against the system.

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[boatmike]

Hmm..
Guess I will stick my neck out again. It's horses for courses as I see it.
I have owned monohulls and cats of various sizes up to 45 ft with various main reefing systems and would offer the following.....

If I was sailing long distance, i.e. full blue water sailing (which I used to do when younger) I would keep everything as simple as possible on the basis that anything that can go wrong will go wrong and at the worst possible time. (Mr sod's first law) Under this regime reef early and don't take chances. Even slab reefing with lines back to the foot of the mast or cockpit can tangle and jam and do.... When I was younger and more agile and ocean sailing I would not have given in mast systems a second look and if I bought a boat with one on I would have removed it.

Now I am older (61) and sail a cruising cat (Prout Snowgoose Elite 37) from port to port with never more than 6 days at sea, often single handed. I have an in mast system with vertical battened sail and it is excellent.
Yes it is correct that you can loose roach (curvature in the back of the sail) with older systems but vertical battened systems such as Easyreef have solved this problem so the loss of sail area is minimal. The thing most people don't recognise is that it is so easy with a properly setup system to reef that you don't have to reef early and can carry maximum sail area until it is really necessary to reef. Often I find myself sailing past other boats under full sail when they have (very sensibly) reefed before me....
Jamming should not be a problem if all lines are set up properly (many systems are badly installed) and everything is maintained properly and lubricated.
You must however also make provision for cock ups and if the sail jams you need to be able to roll it externally and stick a gasket around it and the mast until you can find a quiet moment to sort it..... Not a disaster when coastal cruising but not nice in mid Atlantic. I would add that the Snowgoose has a tiny mainsail and primarily sails on headsails. I have never experienced a jam on either this boat or my previous one that were both similarly equipped however.
I agree with the guy who said don't turn down a good boat if it does not have in mast reefing fitted though. It's a nice to have if it is set up right and suits your type of sailing but it's not as important as all that!

All this also applies to roller reefing headsails too of course and I find it puzzling that people have accepted these for their obvious advantages but still rail on about mainsail in mast roller reefing which is fundamentally the same thing.

Find yourself the boat you would like to have and don't concern youself with mainsail reefing systems too much. Slab reefing can easily be retrofitted if not present and works well. DONT however buy a boat and retrofit a "bolt on" in mast system. These are nearly all poorly engineered and add a lot of weight to the mast which you don't need. Replace the whole mast or accept what you have!

Hope this helps.


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[HaraldS]

I'm with you on that "boatmike". For all the same arguments including geeting older and sails getting bigger. Mine is some 60sqm. Many of the same arguments were around when furling headsails showed up first and on a relative scale they are at least as inefficient as in-mast mains. All the same problems, like accidental unfurling, when the reefing line breaks, to jamming, weight aloft and poor shape were cited. Now with respect to headsails, furling seems to be accepted.
The shape with vertical battens is indeed excellent, and remains very good even when reefed.

If I have one reservation left, then it is weight aloft, and unfortunately that is also true for the furling headsails of which I have two. I don't have any doubts about the safe an reliable operation. A bonus is that I don't need to carry a tri-sail any more, since I can make the mainsail any size. Off course anything can break. But I also remeber a case years back on a really ordinary boat, where the top sleeve of the main halyard disintegrated and there was no way to get the main down ather than climbing the mast it rough conditions.

Interestingly all you read in magazines and forums is the same cliche of furling mainsails being a real bad choice, which is quite in contrast to the number of furling mains I see....

I'd certainly be very happy with well working fully battened main, with good slab reefing and lazyjacks that don't catch the sail while hoisting, but when we are sailing short handed I feel that I have a safer option with the in-mast furling main.

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[Trevethan]

As others have said KISS appplies here too.....

As for you handling things single handed despite having swmbo on board -- strongly suggest you get swmbo involved early on with pleasant sailing experiences -- fun in the med or carribean in a flotilla holiday so she will be more willing to help. Sailing a big boat on your own is hard work and a little help makes life a lot easier!

Also remember the golden rule about reefing -- do it early -- that means you can do it at the mast in safety and not have to worry about in mast systems that bugger up or lines leading back to cokpit getting tangled.



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[Talbot]

Having gone from normal slab reefing to slab with full length battens, and then to behind mast rolling, I much prefer the later especially when single handed. The only proviso is that you should have a small winch in a position to be able to manage the control lines. (makes handling much easier)

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[MainlySteam]

As no one seems to have mentioned it, I wonder what the predjudice is against in-boom mainsail furling.

I am not promoting it at all, but it does not impose the same compromises on sail cut and mechanics as in mast does - plus you can still get the sail down if the furling jambs (as I have seen does happen).

John

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[Koeketiene]

A friend of mine works in a sail loft - they also rig & maintain all sort of furling systems.

Quote I thank God for in-mast furling. For it assures that I will never go hungry Unquote.

Nuff said



<hr width=100% size=1>Fair winds.
If not... reef early!

 

[Ric]

I chose in-mast reefing for my boat because I also single-hand almost exclusively. Mostly, I am glad I chose in-mast reefing. It is very useful when single-handing, especially at night and when tired, to be able to reef and unreef very quickly and easily. Bear in mind also that winds in the Med are often very variable, so one has to reef and unreef more often than in other parts of the world.

It is true that a conventional in-mast reefing sail is not a nice sail - it is about 6% smaller than a slab-reefing sail, and is not as easy to get a nice shape so you do lose a bit of light wind performance. However, I have a battened in-mast reefing sail from Elvstrom (look on their website for details). This has exactly the same surface area as an equivalent slab-reefing sail and a nice rounded luff supported with battens. It is much easier to get a nice twist to the sail. It has never jammed, despite the battens. Elvstrom tell me that its performance is identical to a slab-reefed sail.



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[Bejasus]

In boom reefing as opposed to the others

I had the same thought as mainlysteam. Surely this has benefits in reefing dropping the sail when jammed and weight aloft., or am I missing something?

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[MainlySteam]

Re: In boom reefing as opposed to the others

I too am wondering what I am missing hoo.

On anything where the mainsail is able to be manhandled ie not a super yacht or something similar, my own preference is for slab reefing (when I see a very competent ex sailmaker then yacht builder/designer put slab reefing on the 55 footer he built for himself for he and his wife to sail in his retirement, so is not young, I suspect he had very good reasons to do so). However, if had to have either in mast or in boom, I would go for in boom everytime.

The following are the faults I can think of with in mast furling but which do not apply to in boom:

- much longer mandrel so more prone to jambing/mechanical problems.
- mast is heavier, and includes the extra weight of the mandrel ALL the way to the top so reduced stability.
- when reefed the centre of mass of the sail stays in the same place so reduced stability compared to other reefing (I accept this fault lies with foresail furling also, but changing a foresail both from the point of view of having to be right on the bow and also do a complete sail change makes changing large non furling foresails a much more tiresome and dangerous matter than reefing a non-furling main.
- set of the sail is compromised significantly (you do not see in mast used on race boats, but in boom is used on some race boats)
- jambing at sea leaves one with the only solution of destroying the sail if it is imperative to reduce sail to protect the boat.

I cannot think of any fault that in boom furling has which is not shared with in mast furling (that is not to say in boom does not have faults).

Can someone tell me what the love affair with in mast furling is (the only thing I can think of is that it allows a loose footed sail - hardly a benefit)?

John

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[Robin]

Re: In boom reefing as opposed to the others

Hi John

My sailmaker told me that the teflon (?) or whatever luff tapes needed for boom roller sails (they do not normally have sail slides) do not last very long, another nice little winter earner he said!

As for loose footed, our new fully battened slab reefing mainsail is being made with a loose foot, seems to be the in thing.

Robin

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[HaraldS]

Re: In boom reefing as opposed to the others

Have almost no experience with teh modern in-boom systems. Some 30 years ago we had a thing that turned the whole boom via aworm gear and it sure was the worst system I ever experienced.
I have been briefly watched a sister ship that had a new make of in-boom furling and from what I could tell the trouble wasn't so much reefing, but getting the sail up. In order to furl it, you need to detouch it from the mast, and more difficult attach it when hoisting.
I know there are new systems that even allow for fully battened sails, but I haven't figured out how they attach the mast slides???
Obviously you need to set the boom in exactly a rectangular angle before grinding away, but that should be a lesser problem.


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[boatmike]

Re: In boom reefing as opposed to the others

Right again Harald,
In boom sails are no improvement on the 1960's boom rolling monsters at all. A reefed main with one of these is worse than just about everything else.
What you will remember from your past experience is that as you roll the sail around the boom the fullness of the sail bags up and causes you to need to pull the mainsail boom down almost to the deck to try to flatten the sail. What you are left with is something that looks like granny's knickers! Worse than useless going to windward. The cut of an in mast sail on the other hand can allow the sail to be cut to roll evenly around the foil like a headsail does and present a more respectable shape even when heavily reefed.
Like a headsail system however the sail needs to be cut to allow for this as anyone who has ever tried to convert a hanked on sail to roller reefing will tell you.
Properly cut sails on well engineered foresail or mainsail reefing systems work well. But then so do slab systems without compromising the shape of the sail.
In boom systems are rubbish. Thats why a very large and increasing number of boats are seen with in mast systems and almost no in boom systems are seen .... If you want an informed opinion of in boom reefing ask someone who has got one (if you can find one) not someone who is prejudiced against in mast systems and has no first hand experience of either assuming that you achieve the same sail shape either way...... You don't!
ANY roller reefing sail is a compromise shape. Thats why racing boats don't use them. For the majority of cruising yachtsmen however the performance difference of a hanked on sail and a PROPERLY CUT roller reefing sail either Main or Genoa is minimal. For those who want simplicity, less to go wrong, and ultimate performance however have slab reefed main, and hanked on foresails. There is no in-between.......

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[Bejasus]

Re: In boom reefing as opposed to the others

http://www.profurl.com
http://www.furlboom.com

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[boatmike]

Re: In boom reefing as opposed to the others

And your point is exactly?
Have you ever used one?
Do you know anybody who has and likes it?


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[Talbot]

Re: In boom reefing as opposed to the others

I cant disagree with your final conclusions, however the in/behind mast debate is not complete without mentioning full length vertical battens. They make a big difference to the set of the sail and its shape especially when in light airs. Furthermore proper use of the loose foot will make a big difference. I have noticed a major improvement in my light air performance since changing from my old fully battened slab reefed main to a vertically battened easy-reef system (probably cause the old sail was well past it's use by date /forums/images/icons/smile.gif). There has also been a major improvement on useability for me with single handed useage, despite the odd jam on the reefing line cause I dont have it adjusted quite right.

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