Irrational Fear of In-Mast Furling?

[marcot]

Martin&Rene
Is your HR ' s friend satisfied? How did he fit the track? Closing the slot with a riveted cover? Is the system strong enough ?

 

[horatio_nelson]

Doubt if many cruising boats use a Cunningham.

A fair proportion do, me included. A very useful sail control and easy to rig (assuming sail has cringle / ring / loop / whatever)

Needs a little tug here (RTIR 2016)

 

[NormanS]

A fair proportion do, me included. A very useful sail control and easy to rig (assuming sail has cringle / ring / loop / whatever)

Needs a little tug here (RTIR 2016) View attachment 64384

Doesn't look as if it's doing much for you there.

 

[Kurrawong_Kid]

I'm not at all sure why the attitude (presumably height) of the boom should be important, since the sail is not directly attached to the boom. I can only speak for my own, where it is loose-footed, and the clew has a sheave through which runs the double purchase outhaul. Other systems may be exist where the height matters, but it makes no difference with mine.

Absolutely critical on mine! I have the gas kicker set to the exactly correct angle and make sure boom is down to that before furling. No problem then to set sail. Neglect of the above leads to difficulties getting the sail out because the leech doubles over and jams in the slot.
One advantage of inmost I didn't foresee is in fitfull winds. It's only 10 seconds to furl or set sail so motor used less. When I had slab reeling I just couldn't be bothered to keep going head to wind to hoist or lower sail through lazy jacks.

 

[dragonvc]

Now on the 7th page with very little doom and gloom regarding mainsail furling.However reference is made to the reliability of headsail furling but today heard of a top swivel failure and last year a friends boat had a forestay break within the foil.Does thorough inspection with mast down prevent these issues and is that maintenance of inmast furlers a necessary requirement for safe sailing.Despite all these assurances I remain a inmast furler sceptic,but with increasing numbers fitted to boats we shall see what happens.

 

[Tranona]

Now on the 7th page with very little doom and gloom regarding mainsail furling.However reference is made to the reliability of headsail furling but today heard of a top swivel failure and last year a friends boat had a forestay break within the foil.Does thorough inspection with mast down prevent these issues and is that maintenance of inmast furlers a necessary requirement for safe sailing.Despite all these assurances I remain a inmast furler sceptic,but with increasing numbers fitted to boats we shall see what happens.

No need to wait - after all they have been around for getting on for 30 years and there are thousands in use. So not sure what you are waiting for. The easiest way to resolve your scepticism is to buy one and discover for yourself there is nothing to worry about provided you are aware of how to use it properly and carry out the minimal maintenance required. Just like any other kind of well engineered mechanical equipment.

 

[horatio_nelson]

Doesn't look as if it's doing much for you there.

No, on that occasion it wasn't

 

[Neil_Y]

My main reason for not wanting in mast furling is that the mass of the sail stays quite high up, slab reefing lowers the mass of the sail and needs less in the way of mechanics that also add weight up the mast. If I get rolled or knocked down I want less weight up the mast and less windage.

 

[rotrax]

My main reason for not wanting in mast furling is that the mass of the sail stays quite high up, slab reefing lowers the mass of the sail and needs less in the way of mechanics that also add weight up the mast. If I get rolled or knocked down I want less weight up the mast and less windage.

Well, with the system Island Packet use the windage would be less. 0nly the area of sail in use is able to grab the wind, the rest is neatly rolled around the furling foil inside the mast. The Charleston Spars extrusion is the same overall section as the optional slab reefing mast. There will be no large mass of reefed sail in the lazyjacks on the boom to catch the wind.

As for the weight-is that really significant? If you look at the amount of sailcloth rolled around an in mast system the shape of the sail means the most sailcloth will be in the lower third of the mast. With a slab system all the weight of the sail will be immediatly above the boom, which as you maintain is substantially lower. Remember, in mast reefing/furling is a cruising set up for easy sail handling with a small crew. Compromise is the name of the game.

But, in the real cruising world, on a well found vessel, prudently managed in heavy weather, is the weight in the mast a major issue?

I expect not.

 

[Tranona]

My main reason for not wanting in mast furling is that the mass of the sail stays quite high up, slab reefing lowers the mass of the sail and needs less in the way of mechanics that also add weight up the mast. If I get rolled or knocked down I want less weight up the mast and less windage.

Suggest you weigh the volume of sail that is "high up" and then think about other things that are often added to masts like radomes and radar reflectors.

Do you think that designers are not aware of the potential issue, and might just take this into account when designing boats for in mast? In the case of my boat, the section of the mast is slightly less and the builder advised when asked that the stability of the in mast is exactly the same as the conventional rig.

90% of HRs over 37' for example are specified with in mast. Do you seriously think they are unstable?

There maybe some merit in your argument with some of the retrofit systems popular in the early days, particularly with the heavy masthead rigs that were common at the time, but those things are long gone and suspect many have been removed.

Th reality is that in certain conditions just about any design of smallish yacht can be overwhelmed and roll - and some of the best known involve "traditional" style designs. In fact one is described in an article in this month's YM. Perhaps it is because owners of this type of boat are more adventurous and go places where conditions are more extreme (as in this case).

 

[doug748]

....
As for the weight-is that really significant? If you look at the amount of sailcloth rolled around an in mast system the shape of the sail means the most sailcloth will be in the lower third of the mast. With a slab system all the weight of the sail will be immediatly above the boom, which as you maintain is substantially lower. Remember, in mast reefing/furling is a cruising set up for easy sail handling with a small crew. Compromise is the name of the game.

But, in the real cruising world, on a well found vessel, prudently managed in heavy weather, is the weight in the mast a major issue?

I expect not.

I would not expect an Island Packet to be unduly troubled by the loss of stability but for some boats it would be very serious. The RYA changed their syllabi some years ago to highlight the problem.

So the OP really needs to choose his boat with attention to the possibilities, if he decides he want the convenience of the system. For an older sailor, going places in a larger boat, there is a lot to be said for ease of use.

 

[geem]

Absolutely critical on mine! I have the gas kicker set to the exactly correct angle and make sure boom is down to that before furling. No problem then to set sail. Neglect of the above leads to difficulties getting the sail out because the leech doubles over and jams in the slot.
One advantage of inmost I didn't foresee is in fitfull winds. It's only 10 seconds to furl or set sail so motor used less. When I had slab reeling I just couldn't be bothered to keep going head to wind to hoist or lower sail through lazy jacks.

With our slab reefing on cars we have never gone head to wind whilst sailing to lower of raise the mainsail. If you need to do that then imho you system is set up wrongly. The only time we would go head to wind is when we are dropping the sail to go into a harbour but not necessarily every time. I have nothing against inmast reefing along as it is on somebody else mast not mine. I have never had it on any of my boats and what you dont have you dont miss. I like the simplicity of slab reefing and the excellent set of the sails with reefs in including the third reef which I think is impossible to replicate the same excellent sail shape in any inmast reefing system. Not an issue down wind but to windward is gets relevant

 

[Dockhead]

I've sailed some 20,000 miles with in-mast furling on my present boat.

It does not suck, and in fact has some significant advantages. But I will probably have a normal full batten sail on my next boat.

Advantages:

1. Ideal storage of the sail protected from UV and weather inside the mast. A very significant advantage, extending life of the sail, reducing maintenance, reducing deterioration of the sail due to creases, and completely eliminating the effort of flaking and covering the sail.

2. Reef without leaving the cockpit or heading into the wind. Means you can increase or decrease sail area effortlessly, always having the right amount of sail up for conditions. Big advantage.

3. Reef in infinite increments, down to handkerchief size.

4. In-mast furling sail gets flatter as it furls in (I have no idea why), so is excellent in heavy weather. No storm trysail is needed if you have in-mast furling.

5. Sail is simpler in construction so cheaper than a full batten one.


Disadvantages:

1. You can't have roach, so big performance hit, especially if you have a battenless hollow leech main as usually comes standard. You can claw some performance back with straight leech and vertical battens -- what I have now, with good results.

2. In-mast furling doesn't like blown out or baggy sails. You really, really want laminate sails, for in-mast furling. Laminate sails work much better in the furling mechanism, and you also get some performance back with them.

3. Weight aloft and windage of the fatter mast. Exacerbated by usually taller mast to try to make up for no roach. Big disadvantage.

4. You can't bend the mast so you can't use backstay adjustments.



I don't mention jamming, because I don't think it's a significant problem if the sail is in decent condition and you use the system correctly.


In my opinion, in mast furling makes little sense in lower latitudes with little strong weather. Or for boats used for local or coastal cruising only. Up at these latitudes, though, I think it does make a lot of sense for many sailors, especially long distance or all-weather sailors, other than those concerned about the last bit of performance.

 

[alant]

I've sailed some 20,000 miles with in-mast furling on my present boat.

It does not suck, and in fact has some significant advantages. But I will probably have a normal full batten sail on my next boat.

Advantages:

1. Ideal storage of the sail protected from UV and weather inside the mast. A very significant advantage, extending life of the sail, reducing maintenance, reducing deterioration of the sail due to creases, and completely eliminating the effort of flaking and covering the sail.

2. Reef without leaving the cockpit or heading into the wind. Means you can increase or decrease sail area effortlessly, always having the right amount of sail up for conditions. Big advantage.

3. Reef in infinite increments, down to handkerchief size.

4. In-mast furling sail gets flatter as it furls in (I have no idea why), so is excellent in heavy weather. No storm trysail is needed if you have in-mast furling.

5. Sail is simpler in construction so cheaper than a full batten one.


Disadvantages:

1. You can't have roach, so big performance hit, especially if you have a battenless hollow leech main as usually comes standard. You can claw some performance back with straight leech and vertical battens -- what I have now, with good results.

2. In-mast furling doesn't like blown out or baggy sails. You really, really want laminate sails, for in-mast furling. Laminate sails work much better in the furling mechanism, and you also get some performance back with them.

3. Weight aloft and windage of the fatter mast. Exacerbated by usually taller mast to try to make up for no roach. Big disadvantage.

4. You can't bend the mast so you can't use backstay adjustments.



I don't mention jamming, because I don't think it's a significant problem if the sail is in decent condition and you use the system correctly.


In my opinion, in mast furling makes little sense in lower latitudes with little strong weather. Or for boats used for local or coastal cruising only. Up at these latitudes, though, I think it does make a lot of sense for many sailors, especially long distance or all-weather sailors, other than those concerned about the last bit of performance.

The one downside not mentioned, is the experience of an Oyster owner, who parked in a marina near Cannes. His inmast slot acted like an organ pipe, resulting in very loud groaning noises which echo'd over the whole marina much to the annoyance of other residents,

 

[Dockhead]

The one downside not mentioned, is the experience of an Oyster owner, who parked in a marina near Cannes. His inmast slot acted like an organ pipe, resulting in very loud groaning noises which echo'd over the whole marina much to the annoyance of other residents,

That would be awful!

But I've never observed this, or experienced it on my boat.

 

[Saguday]

Me neither. The only noise we get from ours is when the main is taken off and the furler slats around inside the mast if it's windy - sounds like the bells of doom tolling. Can be sorted with a bit cloth wound round inside though so no biggy.

Love our inmast furling, 11 years of using it.

 

[Leopold Bloom]

With our slab reefing on cars we have never gone head to wind whilst sailing to lower of raise the mainsail. If you need to do that then imho you system is set up wrongly. The only time we would go head to wind is when we are dropping the sail to go into a harbour but not necessarily every time.

Could you elaborate on how you do that, particularly when running downwind?

 

[geem]

Could you elaborate on how you do that, particularly when running downwind?

When running down wind we would pull the mainsheet in until we had the boom at about 45degrees to the boat. We would have a preventer tight to ensure the boom wasnt wobbling about or risk jibing. We would let the main halyard off to lower the sail but with the wind pressure in the sail it wont drop. We would then put the reefing line on the reefing winch at the mast and pull in the reef. This action pulls the sail away from the spreaders and the mast and reduces friction thus allowing you to winch the sail down and put the reef in. We dont have a topping lift on our boat but instead we have a rod with a spring that supports the whole boom weight so its probably a little easier for us. Works every time for us

 

[doug748]

I've sailed some 20,000 miles with in-mast furling on my present boat.

It does not suck, and in fact has some significant advantages. But I will probably have a normal full batten sail on my next boat.

Advantages:

1. Ideal storage of the sail protected from UV and weather inside the mast. A very significant advantage, extending life of the sail, reducing maintenance, reducing deterioration of the sail due to creases, and completely eliminating the effort of flaking and covering the sail.

2. Reef without leaving the cockpit or heading into the wind. Means you can increase or decrease sail area effortlessly, always having the right amount of sail up for conditions. Big advantage.

3. Reef in infinite increments, down to handkerchief size.

4. In-mast furling sail gets flatter as it furls in (I have no idea why), so is excellent in heavy weather. No storm trysail is needed if you have in-mast furling.

5. Sail is simpler in construction so cheaper than a full batten one.


Disadvantages:

1. You can't have roach, so big performance hit, especially if you have a battenless hollow leech main as usually comes standard. You can claw some performance back with straight leech and vertical battens -- what I have now, with good results.

2. In-mast furling doesn't like blown out or baggy sails. You really, really want laminate sails, for in-mast furling. Laminate sails work much better in the furling mechanism, and you also get some performance back with them.

3. Weight aloft and windage of the fatter mast. Exacerbated by usually taller mast to try to make up for no roach. Big disadvantage.

4. You can't bend the mast so you can't use backstay adjustments.



I don't mention jamming, because I don't think it's a significant problem if the sail is in decent condition and you use the system correctly.


In my opinion, in mast furling makes little sense in lower latitudes with little strong weather. Or for boats used for local or coastal cruising only. Up at these latitudes, though, I think it does make a lot of sense for many sailors, especially long distance or all-weather sailors, other than those concerned about the last bit of performance.

What a nice change to see a balanced post.

I think the other condition where this kind of system is useful is where mainsail hoisting (or indeed any deck work) becomes a challenge due to age, or infirmity. Or as I eye them, probably in my case, bone idleness.

 

[Tranona]

What a nice change to see a balanced post.

I think the other condition where this kind of system is useful is where mainsail hoisting (or indeed any deck work) becomes a challenge due to age, or infirmity. Or as I eye them, probably in my case, bone idleness.

At last you have seen the light. Exactly what I have been saying - with the exception of Disadvantage 3. A larger or taller mast may be the case on the his boat, but it is not on newer boats. The mast on all the new boats I looked at (and on my old 2001 boat) were essentially the same as for a conventional sail.

BTW you can check all my previous posts on the subject to confirm. I have been completely consistent - as it is all pretty obvious when you have the experience.