in-mar furling vs traditional mast

[AiniA]

I am a fan of our roller main, but I think that not all furling mains are equal. We have a Hood system and it has proved very reliable and useful. You need to figure out how to use it but it is a great system on a boat our size (45' and 40,000 pounds). It makes reefing dead easy and you can reef to whatever extent you want (6 1/2 reefs anyone). Most useful for balancing the boat with vane steering too. We have a separate track for a trysail next to the main's slot but have never used the trysail - we have reefed the main down to trysail size several times.

[barnakiel]

TRYSAIL situation:

1) you are unlikely to ever need a trysail with in-mast as you can trim the main down to the size of the required trysail area; note the clew portion is not only the strongest but also covered with extra cloth (UV patch),

2) quality in-mast extrusions do have a groove, vide image, use plain trysail with sides if that's what you think is best for you.

https://encrypted-tbn2.gstatic.com/i...2c8T8OAmp3wgTA

image attribution: Selden

Cheers,
b.

[Sailor Doug]

Speed loses only happen with apparent wind of less than 12 knots.


Sent from my iPad using Cruisers Sailing Forum

[Dockhead]

Originally Posted by UNCIVILIZED

Also, a (Key) point (or points) which I didn't mention earlier, is that with a conventional main, you have the option of a dozen or so controls to use, in order to shape the sail with. Which, with a RF main, are completely lacking, and cannot be added.

Including a few, which are handy for things like; increased power, reduced weather helm, better pointing, reduced pitching & rolling, & decreasing heeling moment; all while maintaining the sail's/sail plan's power.
Basically; items of little import, unless you're concerned with things like; comfort underway, or trying to get somewhere under sail.

That said, it's good that spar makers are giving folks the option to fit Trysails to their rigs. But, yes, quite honestly, this is the first I've heard of it until now.


PS: By willingly giving up 1/2 - 3/4kt of speed, you've just cut your VMG by 15% - 20% or more. So it's not such as small a loss as it would, at first glance, seem.

And in doing so, you've drastically reduced the number of harbors, which you can comfortably reach in a day's sail.

A DOZEN controls missing from an in-mast furling mainsail?? I guess there have been some great leaps forward in technology in the half year or so since I was on a boat with full batten mainsail . It had mainsheet, traveller, vang, outhaul, halyard, backstay -- just like in-mast furling boats. What other controls are there? Runners on a fractional rig, cunningham, mast rotation? What are the other nine?



Concerning the performance hit from in-mast furling, you can't make blanket statements about "giving up 1/2 - 3/4 knots of speed". It doesn't work that way at all, because it's different on different boats and different conditions. The performance penalty of in-mast furling is very real, and might be more than a knot under some conditions and on some boats, but it is zero under a wide range of conditions encountered offshore.

In general, for cruisers, you will feel the performance hit, and the hit might be painful, if you are a keen sailor AND you are sailing a lot in light air conditions. In higher latitudes and windy conditions, you may not feel a performance hit at all. In very windy conditions, an in mast furling main may perform significantly better than a full battened one because it gets flatter and flatter as it's furled in, and can be reefed to small sizes a conventional main won't go to. Plus the airflow at the bottom of a reefed furling main is much better than a reefed regular main.


Note that you can have vertical battens with in-mast furling mains, something which gets mixed reviews. I took a risk with that when I had new sails made last year, and -- knock on wood -- the results have been excellent so far. I don't even notice the battens when furling, and the straight leech massively improves the shape of the sail compared to the ugly hollow leech which you would otherwise have.


Note also that in-mast furling works much better with laminate sails, than with woven ones. That is because laminate is thinner and rolls up tighter, making it much easier to get in and out of the mast. 99% of jams (roughly) with in-mast furling sails occur with blown-out Dacron sails which haven't been used in years. Such sails unroll inside the mast and form an amorphous mass which jams when you try to pull them out. That's why many delivery skippers hate them. A tip: Always tighten up the roll before you unfurl.


The worst things about in-mast furling, in my opinion, are the weight aloft, and the thick mast section. Those are big drawbacks, and are the main reasons why my next boat will likely have a slender conventional mast. But for many cruisers, the benefits of in-mast furling far outweigh the drawbacks. Certainly, something approaching 100% of high end cruisers over 40 feet, in Northern Europe, are delivered with in-mast furling, which should tell you something.

[Dockhead]

Originally Posted by Sailor Doug

Speed loses only happen with apparent wind of less than 12 knots.. . .

Depends on the boat and point of sail; you can't make a blanket statement.


On my boat, I feel a performance hit when hard on the wind in anything below about 20 knots, roughly, I would say. Obviously it will be more, the lighter the wind, and by 12 knots has become pretty painful.

[kas_1611]

Personal experience with a Selden In Mast Furler on a 40ft cruiser has been excellent. We have had hull speed out of her and the limitless reefing gives great control in a blow. Never tried, or needed, to reef it down to a trysail but might just look into that this season.

Yes there are some limitations due to the mechanics of the system but as long as you respect them and maintain them you should have little to no problems. They are also super easy for shorthanded sailing. It's just the two of us onboard and we can quickly reef in when needed.

Some of our secrets to a happy life are:

• Mark the kicker to relocate the sweet spot for furling all the way in. Our system is quite tolerant but it is much easier in the zone.
• In light winds use your traveller (or equivalent) to bring the boom up wind and increase the twist. We have a "german" mainsheet with 2 sheets so with the boom up traveller we can balance the mainsheets and still pull the boom down vertically
• Mark your boom with "normal" reef points (1st, 2nd, 3rd) so you have a guide for reefing in
• Grease and WD40 all the moving parts regularly. Candles are great for lubing the outhaul runner/track
• Check which way your sail rolls in. When trying to reef in avoid having the sail pressing against the mast (normally this is sail out to Stbd) as this massively increases the load and resistance. It is actually easier to keep a little wind in the sail as this reduces flogging.
• practice practice practice - make sure you are happy with the routines in calm conditions so you know what to do and how when the excrement hits the air con

Lastly on the subject of performance yes a normal in mast furler does lose a little with the negative roach but you can get vertically battened, positive roach furling mains which, from reviews I have read, give you all the performance of a traditional main.

One thing you definitely lose though is the main halyard to gain access to the mast top as it will almost certainly be wired on to the top roller. I had to use the topping lift with the spinnaker halyard as my backup when changing the mast top anchor light bulb.

Hope this helps

Keiron

[Clivevon]

Hi,
My first boat was 31 ft with in mast furling. It was really easy to use. Current boat is 36 ft ketch (42 foot mainmast) with normal slab reefing led back to cockpit and with lazy jacks. 3 reefs, 3 lines on luff, usual 3 pennants on leech. If it gets too bad I can drop the lot and sail on jib and mizzen. Works well for my offshore sailing, not oceanic.

IMHO the choice is yours - other issues will be more critical. I would actually be more concerned that your first boat has a 56 ft mast and will be run by you and your wife. So what is that? A 45 footer?

The advantage of inmast furling is that it is easy to use. The disadvantage is that it is a compromise wholly aimed at making sail handling easier, while decreasing performance, sail control, simplicity and seaworthiness.

For me a lot depends on how much experience you already have and how long you intend to keep this boat? If starting off on a 45- footer you will probably appreciate all the help you can get to make life easier. However, after a while you might get a bit fed up with the compromises - or you might not. In the end, it's up to you...

You can get a vertical fully battened inmast furling mainsail so you have the roach giving extra sail area. You still have all that weight aloft, though.

Either way, you can have a lot of fun...

[phydeaux]

Have sailed with an in-mast system on a cruise/charter, and was happy until we sailed into a blow. That lead to reefing issues. We have a Leisure Furl in-BOOM on our current boat, and found it to be easier and more reliable, and with a minimal change in performance.

[captmikem]

It is a pretty easy question if you are honest with yourself.

Are you really going to use your boat to go someplace, or just coastal hop.

Most people are coastal sailors, they have a schedule and want to be in a marina or anchorage by dark, and so crank up the engine if they get down under 5 kts or so, which means hoisting and dousing the main at least twice per day. Most folks have a comfortable window of wind and when it picks up much over 18kts prefer to just douse sail and motor. If this is you a roller furling main would be fine, because main is much smaller (no roach), no real battens, and the shape does not really matter that much, and it is easy to roll out or in, and you can do it from the "safety" of the cockpit.

On the other hand if you plan on traveling with your boat, and you plan on 120 to 150 mile days (average 5 or 6 kts), you want a main that is going to deliver power to your boat. You will lose at least half a knot, that is 12 miles or nearly 3 hours per day minimum. That adds a day a week.
Also keep in mind a good sailing boat is designed to balance center of effort and center of lateral resistance, with a roller furling main your COE moves forward and you have to balance that with less headsail or you will have weather helm.

And, as always, slab reefing with everything at the base of the mast is easy to see when something is going wrong, easy to operate, and easy to fix when at sea.

I sailed an 80 foot cutter around the world with just my wife and myself. Took three years and in that time I reefed hundreds of times with very few problems. The boat I have now, the PO went to a mast furler, which I find handy when day sailing, but a real pain if I want to get someplace. I will be changing it over soon.

Not telling you what to do, just giving my opinion based on my experiences.

Good luck with whatever you decide.

Michael

[sailing_gal]

I am a singlehander who has had a standard main with stackpack and lazy jacks and currently have a RF main. I can tell you that being shorthanded, I am much more likely to pull out the main in lighter wind or for shorter trips than I did with a standard main. The work involved in putting the main up, and then taking it down and stashing it was so much, that for shorter trips, I just didn't bother. Now, I do, and I am sailing more often and motoring less.

And I do have a storm trysail, because I don't want to blow out my mainsail, which should be flatter than a regular sail, in a strong blow. My mast came with a slot on the side for a sail slides, and I can easily attach it and keep it bundled up by the mast if I think I think I may need it.

You may also want to read John Kretschmer's book where he talks about RF masts. He was totally against them.... until he sailed one.

[SimonV]

Originally Posted by goat

Pros and cons for everything that floats. I've had both, so here's my opinion.

RF can jam at the worst possible time (part way back in in a hard blow). Of course a sail slug could jam in the top of the track. Worst case scenario your R/F jams in a horrible blow, you cut the out haul, bunch the sail up against the mast as best you can, then maypole your spinnaker halyard around it until you've got a chance to repair the jam.
Other opinions will be very different.


goat

I have seen this point referenced before, about getting a spinnaker sheet around the mast as stated like a "maypole" to secure a jammed mainsail. It beggars belief that anyone, with any sort of sailing experience could possibly imagine this act, given the abundance of fixed obstructions making this act impossible on a a calm day and god like in a blow. And why would you CUT the out haul? .

[Boston Blackie]

I am a recovering racer and would never have considered sailing with a mast furling main. Uncivilized, I must admit I was surprised by and actually very impressed with the perfomance and adjustability of the electric furling main on a Hinckley SW 42 I raced to Bermuda on a few years ago. I found that by easing or trimming the boom outhaul at any given amount of furl, we could actually shift gears and power up or flatten the main surprisingly well. And we did of course constantly tweak the furl for desired heel angle.

A critical point is that when reefing or furling you always must have the sail rolling to windward on the in-mast mandrel. If you have tacked since reefing and want to shorten further, fully unroll and roll up to windward. This prevents an S bend around the mast slot and dramatically reduces friction and wear on the sail and gear.

I would not hesitate over in-mast furling for shorthanded cruising. That said, we have 2 slab reefs on our J42 and a separate trysail on its own track.

[Dockhead]

Originally Posted by captmikem

It is a pretty easy question if you are honest with yourself.

Are you really going to use your boat to go someplace, or just coastal hop.

Most people are coastal sailors, they have a schedule and want to be in a marina or anchorage by dark, and so crank up the engine if they get down under 5 kts or so, which means hoisting and dousing the main at least twice per day. Most folks have a comfortable window of wind and when it picks up much over 18kts prefer to just douse sail and motor. If this is you a roller furling main would be fine, because main is much smaller (no roach), no real battens, and the shape does not really matter that much, and it is easy to roll out or in, and you can do it from the "safety" of the cockpit.

On the other hand if you plan on traveling with your boat, and you plan on 120 to 150 mile days (average 5 or 6 kts), you want a main that is going to deliver power to your boat. You will lose at least half a knot, that is 12 miles or nearly 3 hours per day minimum. That adds a day a week.
Also keep in mind a good sailing boat is designed to balance center of effort and center of lateral resistance, with a roller furling main your COE moves forward and you have to balance that with less headsail or you will have weather helm.

And, as always, slab reefing with everything at the base of the mast is easy to see when something is going wrong, easy to operate, and easy to fix when at sea.

I sailed an 80 foot cutter around the world with just my wife and myself. Took three years and in that time I reefed hundreds of times with very few problems. The boat I have now, the PO went to a mast furler, which I find handy when day sailing, but a real pain if I want to get someplace. I will be changing it over soon.

Not telling you what to do, just giving my opinion based on my experiences.

Good luck with whatever you decide.

Michael

That's certainly one valid approach, but my priorities would be exactly opposite these.

For coastal sailing where you have a greater choice of weather, especially in mild latitudes, I would definitely want a full batten main and I would want a bit more SA/D. Coastal sailing you can concentrate more on sailing, and it's definitely more fun with a regular main. In heavy weather, you just stay home.


It's offshore, especially in higher latitudes, where you often can't just stay home when strong weather blows up, that the benefits of in-mast furling start to shine. Especially where there's much risk of any really big weather. In-mast furling can be a Godsend in really heavy weather. It's much better, vastly better than a trysail, because you can regulate the area seamlessly as the weather strengthens and abates. With a real trysail you bob around without any drive during the lulls, because you don't dare go up on deck and futz with pulling it down, when the next blast will be upon you at any second. With an in-mast furling main, you just roll it out, then back in as you need it, and keep the boat moving.


That's probably a big part of the reason why in-mast furling is almost universal on cruising boats in tougher waters like North Sea, English Channel, etc., whereas it's far less prevalent in milder places like the Med, Caribbean, etc.


Of course a ketch is even better for such tasks, and that's something else I would consider. You also give up performance for this, but wow how comfortable and safe in tough weather.


Concerning Center of Effort -- you have it backwards! When you reduce sail with in-mast furling, you are moving the CE FORWARD, so REDUCING, not increasing the tendency to weather helm. This is a huge plus on boats with hull forms and rigs inclined to weather helm.

On my boat, this is not so important, because with her modern underbody, and rather high aspect rig, weather helm is a linear function of heel angle, and sail balance is almost irrelevant. I can sail perfectly well on main alone, or headsail alone, if I feel like it, and the helm is balanced as long as heel is not excessive (i.e. not over 20 degrees).

But getting the CE forward is important not only to reduce helm, but to reduce the tendency to broach, which is extremely important in tough weather, when a broach can be caused by an odd wave. There's nothing sweeter in a hard blow than a cutter sailing on deeply reduced furling mainsail and staysail alone, with the sail area tightly centered around the mast.

[Sailor Doug]

Originally Posted by kas_1611

Personal experience with a Selden In Mast Furler on a 40ft cruiser has been excellent. We have had hull speed out of her and the limitless reefing gives great control in a blow. Never tried, or needed, to reef it down to a trysail but might just look into that this season.



Yes there are some limitations due to the mechanics of the system but as long as you respect them and maintain them you should have little to no problems. They are also super easy for shorthanded sailing. It's just the two of us onboard and we can quickly reef in when needed.



Some of our secrets to a happy life are:

• Mark the kicker to relocate the sweet spot for furling all the way in. Our system is quite tolerant but it is much easier in the zone.
  
• In light winds use your traveller (or equivalent) to bring the boom up wind and increase the twist. We have a "german" mainsheet with 2 sheets so with the boom up traveller we can balance the mainsheets and still pull the boom down vertically
  
• Mark your boom with "normal" reef points (1st, 2nd, 3rd) so you have a guide for reefing in
  
• Grease and WD40 all the moving parts regularly. Candles are great for lubing the outhaul runner/track
  
• Check which way your sail rolls in. When trying to reef in avoid having the sail pressing against the mast (normally this is sail out to Stbd) as this massively increases the load and resistance. It is actually easier to keep a little wind in the sail as this reduces flogging.
  
• practice practice practice - make sure you are happy with the routines in calm conditions so you know what to do and how when the excrement hits the air con
  

Lastly on the subject of performance yes a normal in mast furler does lose a little with the negative roach but you can get vertically battened, positive roach furling mains which, from reviews I have read, give you all the performance of a traditional main.



One thing you definitely lose though is the main halyard to gain access to the mast top as it will almost certainly be wired on to the top roller. I had to use the topping lift with the spinnaker halyard as my backup when changing the mast top anchor light bulb.



Hope this helps



Keiron

Use McLube no WD40 no WD40 extra $6 is worth it.


Sent from my iPad using Cruisers Sailing Forum

[Pete7]

Well we have heard the closing arguments from the prosecution and the defence, the only thing now is for the jury (OP) to go and try it before reaching a verdict.

Pete