In-mast furling - pros and cons

[Duffer]

I think this topic may have been raised about ten times previously and it seems to boil down to personal preference and priority.
My preference is NOT to have in-mast furling as I have seen many instances of this system stuck fast and unable to go in or out. When it is new with crisp sails it works well but the trouble comes later with baggy sails which have lost their slippiness and crease and jam.
Each to his own choice...!!!

If you want convenience over performance in-mast furling probably works fine for the first few years. Our previous boat (7 years old) had in-mast and it was always jamming. Single-line reefing on our new boat has worked perfectly (last 6 years). On a larger boat you will presumably have electric winches.

 

[SHUG]

The battens were always catching on the lazyjacks and I had to go forward every time to reef. .

Its very simple to devise a system to stow the lazyjacks ay the mast to avoid this problem AND there are plenty of single and double line options to have reefing from the cockpit.

 

[prv]

The battens are not one continous length. They are put together like a chimney sweeps brush. You push a section up the batten packet. Add the next section and continuing pushing up.
To drop the sail you just pull out the battens from the bottom of the sail a section at a time.

Thanks, that makes sense.

Pete

 

[Sailfree]

Its very simple to devise a system to stow the lazyjacks ay the mast to avoid this problem AND there are plenty of single and double line options to have reefing from the cockpit.

On a sailing boat the sails are the engine. Personally I would hate to cut the performance with in mast furling as even with vertical battens the shape is not the aircraft wing you get with horizontal battens.


Its a personal choice with pro's and cons but on a 57 I would go for powered winch and fully battened main. 1st & 2nd reefing points single line. 3rd reef can still be done from the cockpit but require line for luff separate from line for leach. Blocks on sail for reefing lines to reduce friction. Stack pack fitted so that lazy jacks can be lead forward to the mast when sail 100%. Probably worth an extra 2kts over a plain in mast reefing system. Is this a new Jeanneau where the mains are getting bigger and the genoas smaller?

 

[Ex-SolentBoy]

One of the challenges with broken battens is how to get them out. You can pull the batten from the foot of the sail, but if it is broken completely the broken bit stays behind.

Our sailmaker got round this by running a thin, but strong line all the way from the top of the batten to the foot of the sail. You insert this line when you insert the batten, and you tape it to the batten every 2 metres or so. If the batten breaks you can then pull on the line.

Fortunately, we have not had to test this system in anger, but he swears by it so we have continued with the idea.

 

[Talbot]

There are good arguments either way for the in-mast system for smaller boats, particularly when short handed, however, for a 57, I would not even consider an in-mast system, A Boom system would be vastly superior.

Take a look at Leisure furl.

 

[Dockhead]

Our present boat has in-mast furling, my first experience with this system. I am ambivalent about it -- it has a number of plusses and a number of minuses.

The minuses:

1. I had an awful jam with it just before setting off on my first Channel crossing last summer. It was a nightmare and almost ruined the trip. I don't think there is anything so horrible you can do with a regular battened main. That being said, I now know why it jammed and why I wasn't able to clear the jam at first. And I have had no further problems of the sort.

2. It seems to be much harder to trim well. Whether it is because of the lack of battens, because of the hollow leech, or whatever, I don't know, but I often get a stalling sail luff when going to weather which is hard to trim out.

3. It's harder to hoist and strike the sail, because the foil is inside the mast an inaccessible. On the other hand, you rarely need to do this as the sail is very nicely protected inside the mast when not in use.

4. No roach (negative roach, even). Correspondingly, reduced performance.

The plusses:

1. Infinitely variable reefing with no loss of shape (in other words, the shape is no crappier when reefed down than when not).

2. Sail is wonderfully protected inside the mast when not in use.

3. No flaking or covering of the sail after a day's sailing -- which would be quite a lot of work on a sail of this size -- a big plus.

4. Furl or unfurl without heading up -- a big plus.

Neither plus nor minus:

1. I don't know why people think furling mains are easier to reef, furl, or unfurl. In my experience they are not easier. It is somewhat tricky to keep the right amount of tension on the outhaul while furling, and you have to have tension on both ends of the furling line in order to keep good contact with the furling drum. Besides that, you have to be careful with the boom angle. It really takes two pairs of skillful hands, and other than not having to leave the cockpit, I don't see any big advantage in this regard compared to regular battened mains.

2. Sail area. I don't know why people think that this is a disadvantage of furling mains. You just have a taller mast and more headsail oriented rig to compensate. This is different from the issue of lack of roach -- the roachy part of the mainsail contributes disproportionately to performance, if I can believe what I have been told.


For some reason, 50+ foot cruising boats made in the last 15 years are practically unavailable with any other type of mainsail, than a furling one. I don't really understand why, but there must be some reason that they are so strongly preferred by the buyers of this sort of boat.

 

[Dockhead]

Vertical battens do a good job of holding out the roach but they only work if they can be kept exactly parallel to the luff when furling. If they enter the slot at an angle they will jam instantly.

I have been warned many times to avoid vertical battens on in-mast furling mains, for this very reason.

In-boom furling is also supposed to be plagued with jamming problems due to extreme sensitivity to boom angle.

I think it's not an accident that Oyster, HR, and Swan use regular, hollow leech, unbattened mainsails on their in-mast furling rigs. I'm not sure you can even buy an Oyster with a battened main unless you special order it.

I think you have to either go with a regular battened main for best performance, or give up battens if you want in-mast furling. I believe that much of the performance loss can be made up with a taller mast, albeit at the cost of more weight aloft etc.

 

[Twister_Ken]

For some reason, 50+ foot cruising boats made in the last 15 years are practically unavailable with any other type of mainsail, than a furling one. I don't really understand why, but there must be some reason that they are so strongly preferred by the buyers of this sort of boat.

I suspect it may be because the height of the boom above the coachroof makes flaking and tieing-down the main a struggle for those of less than about 6' 8''. I sailed on a 47' boat where putting on the halyard required three mast steps to get to the head of the sail.

 

[Dockhead]

I suspect it may be because the height of the boom above the coachroof makes flaking and tieing-down the main a struggle for those of less than about 6' 8''. I sailed on a 47' boat where putting on the halyard required three mast steps to get to the head of the sail.

Good idea -- I hadn't thought of that. I spent a couple of weeks on a Swan 90 with a battened, laminate, performance mainsail. What a bl**dy b*tch it was flaking, tying down and covering that sail. It took two of us standing on the spray hood (which undoubtedly did it no good) and struggling away for the better part of an hour to do it, with a third handling the halyard. It was an awful job even in calm weather. One day we motored on a short passage instead of sailing just because we dreaded that job at the end.

 

[Magnum]

Good idea -- I hadn't thought of that. I spent a couple of weeks on a Swan 90 with a battened, laminate, performance mainsail. What a bl**dy b*tch it was flaking, tying down and covering that sail. It took two of us standing on the spray hood (which undoubtedly did it no good) and struggling away for the better part of an hour to do it, with a third handling the halyard. It was an awful job even in calm weather. One day we motored on a short passage instead of sailing just because we dreaded that job at the end.

The solution to that problem is a Hall VBoom. You can climb in it and it has a lot of nice features such as being able to pull the lazy jacks forward to hide in the boom. We have specified this boom on our Bordeaux 60.

 

[Mr Cassandra]

Hi

I have a jeanneau 44 which came with a fully battened mainsail. Lost the whole rig and replaced it with an In mast main. Had the mast made 1.4 m taller and the boom 500mm longer to compensate for the loss of sail size.
. If anything, I find the boat quicker than before. I think it could be because the Genoa is also bigger with the increase in mast height. I can get hull speed 8.6 in as little as 16 Knots of wind

 

[Kurrawong_Kid]

Our present boat has in-mast furling, my first experience with this system. I am ambivalent about it -- it has a number of plusses and a number of minuses.

The minuses:

1. I had an awful jam with it just before setting off on my first Channel crossing last summer. It was a nightmare and almost ruined the trip. I don't think there is anything so horrible you can do with a regular battened main. That being said, I now know why it jammed and why I wasn't able to clear the jam at first. And I have had no further problems of the sort.

2. It seems to be much harder to trim well. Whether it is because of the lack of battens, because of the hollow leech, or whatever, I don't know, but I often get a stalling sail luff when going to weather which is hard to trim out.

3. It's harder to hoist and strike the sail, because the foil is inside the mast an inaccessible. On the other hand, you rarely need to do this as the sail is very nicely protected inside the mast when not in use.

4. No roach (negative roach, even). Correspondingly, reduced performance.

The plusses:

1. Infinitely variable reefing with no loss of shape (in other words, the shape is no crappier when reefed down than when not).

2. Sail is wonderfully protected inside the mast when not in use.

3. No flaking or covering of the sail after a day's sailing -- which would be quite a lot of work on a sail of this size -- a big plus.

4. Furl or unfurl without heading up -- a big plus.

Neither plus nor minus:

1. I don't know why people think furling mains are easier to reef, furl, or unfurl. In my experience they are not easier. It is somewhat tricky to keep the right amount of tension on the outhaul while furling, and you have to have tension on both ends of the furling line in order to keep good contact with the furling drum. Besides that, you have to be careful with the boom angle. It really takes two pairs of skillful hands, and other than not having to leave the cockpit, I don't see any big advantage in this regard compared to regular battened mains.

2. Sail area. I don't know why people think that this is a disadvantage of furling mains. You just have a taller mast and more headsail oriented rig to compensate. This is different from the issue of lack of roach -- the roachy part of the mainsail contributes disproportionately to performance, if I can believe what I have been told.


For some reason, 50+ foot cruising boats made in the last 15 years are practically unavailable with any other type of mainsail, than a furling one. I don't really understand why, but there must be some reason that they are so strongly preferred by the buyers of this sort of boat.

I think the point about the height of the boom made earlier is the reason on a large boat. Putting on a sail cover or even zipping a stack pack is difficult above shoulder height, made even more difficult on a yacht with a deck saloon. Many Oysters being built at the moment, with traditional rigs, have a "V" shaped boom and the sail drops into it. Not sure if there is a powered sailcover or something similar.

 

[snowleopard]

A point not mentioned so far is the aftermarket furling option. Rivetting the large track and furling mechanism onto and existing mast can be done but the added weight aloft can have a significant effect on stability.

 

[Juniperskip]

Most of the pros and cons have been aired here. I would place a larger emphasis on the in boom furling system for someone wanting ease plus new to raggy things. I have a simple single line reef system which is easy to use until you want to setup a deep 3rd reef offshore. The in boom system solves that and the risk of jamming is much lower that the in-mast system. I believe Jeanneau are now offering this on the 57. EOLIC & Osprey (CNB60) also have it....

 

[Salty John]

I sail an Amel Maramu (49') from time to time and it has in-mast furling and electric winches. It's a delight when short handed.
I certainly wouldn't add to the potential for things going wrong by having a roach and the vertical battens to support it.
With the relatively small, high aspect main on a modern boat I don't think the loss of drive is significant for a cruising boat. I'd certainly consider in-mast furling on my next long distance cruising boat.

 

[Monique]

Hi

I have a jeanneau 44 which came with a fully battened mainsail. Lost the whole rig and replaced it with an In mast main. Had the mast made 1.4 m taller and the boom 500mm longer to compensate for the loss of sail size.
. If anything, I find the boat quicker than before I think it could be because the Genoea is also bigger with the increase in mast height. I can get hull speed 8.6 in as little as 16 Knots of wind

I have an older Bav 46 with inmast furling... as stated above, the larger Genoa makes up for the reduced mainsail size nicely. My main/genoa 150% lasted 13 years and I have just replaced them; looking forward to sailing faster in lighter airs... Furling reduces the work considerably for short handed crew (GF and I).

 

[NormanS]

1. I don't know why people think furling mains are easier to reef, furl, or unfurl. In my experience they are not easier. It is somewhat tricky to keep the right amount of tension on the outhaul while furling, and you have to have tension on both ends of the furling line in order to keep good contact with the furling drum. Besides that, you have to be careful with the boom angle. It really takes two pairs of skillful hands, and other than not having to leave the cockpit, I don't see any big advantage in this regard compared to regular battened mains.

.

It may depend on what particular make of furling gear you have. I find my (Kemp / Selden) gear very easy, and don't have any of your problems.

Or again, it may depend on precisely how it's rigged. I had never had in until my present boat, and for cruising, would recommend it.

 

[Dockhead]

It may depend on what particular make of furling gear you have. I find my (Kemp / Selden) gear very easy, and don't have any of your problems.

Or again, it may depend on precisely how it's rigged. I had never had in until my present boat, and for cruising, would recommend it.

Mine is also Selden. I don't hate it.

The only problem I have with the furling mainsail on my boat which I consider to be a serious disadvantage is the problem I have with trimming it. And I'm still not sure (even after 53 days at sea so far with it) that it's any inherent aspect of the system, rather than just some mistake of mine.

Have you had any problem with stalled luff of the mainsail? I also have a persistent weather helm which I find very difficult to trim out.

 

[Tranona]

There is not a lot you can do to trim the sail except varying the area and then the draught with the outhaul.

Your description suggests a problem with the sail being cut (or worn) too full. My original sail was like this, but the new flatter sail is much better and trimming for helm balance is excellent.