In mast furling mains - the good, bad and ugly

[slug zitski]

Any roller furling sail, in mast, in boom, or around the headstay is a compromise of convenience over performance. If you don't want to compromise something like performance or longevity, don't get them.

The marine industry targets certain demographics…young guys get the little speedsters, old guys get the big rollers

it works

when you go to the marina all the old guy boats are roller, electric winch , sun Bimini ….at the sailing club it’s wetsuites , bendy masts and everyone looks like Bart Simpson

 

[Veeger]

Yep, we all make our choices. Over time, those choices and priorities change. It is what it is.

 

[Alaris]

For stop and go sailing a furling mainsail is heaven

those furling folks get the most sailing time and have the most fun

This is the real advantage. I’m looking forward to getting out easily and often (mostly singlehanded) with my new in-mast furling boat. A 400ft^2 main is no fun to flake alone, so I’m grateful for the furler.

With SA/D of 14.92 it won’t be fast, and the sails aren’t up to racing snuff, but I’ve got the race boat when I want “performance sailing.”

 

[kdh]

I think the issue with boom furlers is there isn't a lot of experience building them and the sails that work with them, and there are patents that prevented many from using the best designs. It took me a while to get mine dialed in so that it works optimally.

Issues mentioned like the luff tape and batten pockets are valid. Spectra works well.

Greatest unrecognized issue to me? Weight. In light air a heavy boom swinging around in a seaway sucks. Carbon fiber helps that. Also, a good hydraulic rigid vang makes things easier and makes a traveler redundant.

Greatest non-issue? Boom angle.

 

[slug zitski]

I think the issue with boom furlers is there isn't a lot of experience building them and the sails that work with them, and there are patents that prevented many from using the best designs. It took me a while to get mine dialed in so that it works optimally.

Issues mentioned like the luff tape and batten pockets are valid. Spectra works well.

Greatest unrecognized issue to me? Weight. In light air a heavy boom swinging around in a seaway sucks. Carbon fiber helps that. Also, a good hydraulic rigid vang makes things easier and makes a traveler redundant.

Greatest non-issue? Boom angle.

Yah

looks good .

perfect application coastal sailing , stop and go , spontaneous .

boom inertia is a problem

A boom preventer for hoist , strike , reef , motor sailing and many times even upwind in light rolly stuff is absolutely needed .
Stabilize the boom
the red line pictured is the preventer..set to the motor sailing , hoist and strike position .
it’s internal and led back to a winch close to the mainsheet winch .


worthwhile figuring out a system for your boat

 

[accnick]

Yah

looks good .

perfect application coastal sailing , stop and go , spontaneous .

boom inertia is a problem

A boom preventer for hoist , strike , reef , motor sailing and many times even upwind in light rolly stuff is absolutely needed .
Stabilize the boom
the red line pictured is the preventer..set to the motor sailing , hoist and strike position .
it’s internal and led back to a winch close to the mainsheet winch .


worthwhile figuring out a system for your boat

View attachment 559823

A good preventer is cheap insurance on any kind of boat, with any kind of boom.

Don't leave home without one.

 

[AnIdiot]

I think the issue with boom furlers is there isn't a lot of experience building them and the sails that work with them, and there are patents that prevented many from using the best designs. It took me a while to get mine dialed in so that it works optimally.
...

How much draft do you get with yours? I'm advised 8%, which is pretty flat (it's a ProFurl). Goes upwind well, though, and I have a cruising chute when off the wind, so not a big problem, just curious...

Greatest unrecognized issue to me? Weight. In light air a heavy boom swinging around in a seaway sucks. Carbon fiber helps that. Also, a good hydraulic rigid vang makes things easier and makes a traveler redundant.

Concur. I use a boom-brake to help manage it. My boat is well ballasted and doesn't seem to get unbalanced by the rig but I do like to keep in mind the potential for damage if the thing were to get out of control.

 

[221J]

I have a 570 sq ft main. I furl it solo without much difficulty. I am not superman so I use technique. I set the throttle to about .5 knot, head to wind and set the autopilot to hold course. Next, I drop the boom as low as the vang will allow and snug the mainsheet. When I pop the halyard the sail drops about 10 feet and then friction holds it in place. At this point I put in a couple of flakes and bend on the first sail tie. Then using the leech I pull 10 feet increments of sail down and attaching sail ties at each increment until it is flaked. I might redo the first sail tie if it needs it. I have done this many times including inside Great Salt Pond in 20+ knots. My Hydranet offshore sail is a bit easier to flake than my carbon cruising sail in spite of the Hydranet being slippery. If it's blowing much over twenty I may take a reef, or two, and then use the same technique. I'm a 5'10" boomer so I'm not doing this by brute strength. I do acknowledge that this isn't for everyone or every boat.

 

[slug zitski]

With sail design you are some what limited

30 years ago I was involved with one of the first roller boom , inside a boom projects

north sails was involved and we actually made a miniature …perhaps 5 foot long boom on a dingy mast then experiments with sail design ..luff curve, battens and general sail bulk and reinforcements
the big lesson was that the rolled sail must form the same diameter roll at the leech and luff or the stack..luff tension , leech tension was not coordinated

the other issue , was how to handle the leech line

none of the solutions I’ve ever seen are easy to use

 

[kdh]

Here's how I stabilize mine. Just take a line to an additional car on the traveler to make an inverted "V".

 

[slug zitski]

Here's how I stabilize mine. Just take a line to an additional car on the traveler to make an inverted "V".

View attachment 559828

Looks logical

a boom topping lift …especially is you cross oceans , is required to stabilize the boom in a seaway

 

[slug zitski]

Another detail on the boom that needs attention is drainage

at sea that hollow boom can hold a huge quantity of heavy sea water or just rain

so heavy that a topping lift is needed to prevent boom sag

many booms have trouble self bailing or only have a tiny weep hole

have a look at yours

 

[Kiwi Clipper]

Think I’ll stick with a flaking system, Dutchman or lazy jacks. Boat I’ve offered on has the latter, last boat had the former. They all have compromises, just have to pick my personal poison.

What boat did you choose?

 

[kinardly]

What boat did you choose?

Cat 42 Mk II with lazy jacks. 1998 factory main is for shit so will consider going back to dutchman when ordering replacement (soon). 362 sf will pose no problem regardless and furling would be a joke. Boat is more than a little sluggish in light stuff compared to the 40.7 but I keep reminding myself the goal is to get the wife back on the water with me and she is definitely more comfortable on this one, plus it might perk up in more breeze.

 

[Bryanjb]

I’ve been on boats with in boom furling and the luff tension with full length battens is pretty high. Hard to buy into a system that requires heading into the wind to reef offshore.

Fatal Accident At Sea: It Could Happen To Anyone

Fatal accident at sea causes the death of Karl and Annamarie Frank, two veteran sailors on CNB 66 Escape. Offshore sailing is hazardous and anything can happen.

www.cruisingworld.com

 

[Cruisin Loser]

I’ve been on boats with in boom furling and the luff tension with full length battens is pretty high. Hard to buy into a system that requires heading into the wind to reef offshore.

Fatal Accident At Sea: It Could Happen To Anyone

Fatal accident at sea causes the death of Karl and Annamarie Frank, two veteran sailors on CNB 66 Escape. Offshore sailing is hazardous and anything can happen.

www.cruisingworld.com

I've reefed my in-boom main (700 sq ft) offshore without rounding up due to sea conditions. Not ideal but not bad. The sail is heavy and wants to fall, you have to watch carefully and roll in at roughly the same pace. It may not be perfect, but it will certainly get you through. Shaking out said reef really needs to be done with the pressure off the sail.

My mainsheet runs behind the cockpit. I consider it almost as dangerous as that big-ass boom, and emphasize that to guests. I stay very attuned to the positions of people vis-a-vis those two items, and give frequent warnings "that's probably a really unhealthy place to be sitting/standing if something happens".

 

[accnick]

I've reefed my in-boom main (700 sq ft) offshore without rounding up due to sea conditions. Not ideal but not bad. The sail is heavy and wants to fall, you have to watch carefully and roll in at roughly the same pace. It may not be perfect, but it will certainly get you through. Shaking out said reef really needs to be done with the pressure off the sail.

My mainsheet runs behind the cockpit. I consider it almost as dangerous as that big-ass boom, and emphasize that to guests. I stay very attuned to the positions of people vis-a-vis those two items, and give frequent warnings "that's probably a really unhealthy place to be sitting/standing if something happens".

"I wouldn't have my hand there if I wuz you..."

(Speaking to the guy holding onto the middle of the mainsheet or the running backs.)

 

[kdh]

I'll echo Rob in that it is possible to reef downwind, though as Bryan points out not ideal because of the luff friction. I center the boom and go dead downwind to unload the sail as much as possible. An electric winch really helps. If I were an offshore rather than a casual sailor I'd think hard about a system that doesn't require a roll.

Something that surprises me is that the benefit of a stiff furling boom seems under-appreciated. My boom furling shell has a large cross section and is made of carbon fiber so is not going to bend. This means that with a powerful hydraulic vang a traveler and end-boom sheeting don't serve the usual advantage of keeping the boom straight--though maybe there are other reasons to go that route that I don't know.

 

[slug zitski]

Head to wind is when in the harbour…

at sea, for cutter rigged boats, the mainsail is handled with the staysail

you can also do this with the Genoa but it’s a bit big and powerful

you sheet the staysail in tight..full windward trim …then bear off slightly to bubble, back wind the main ..ease mainsheet a bit ..then hoist douse, reef the mainsail

much the same as a conventional slab reef

shaking out a reef at sea is a bit more delicate . I’ve never learned a method to prevent over flogging of the main and guard the luff tape , batten insertion

 

[Kris Cringle]

I'll echo Rob in that it is possible to reef downwind, though as Bryan points out not ideal because of the luff friction. I center the boom and go dead downwind to unload the sail as much as possible. An electric winch really helps. If I were an offshore rather than a casual sailor I'd think hard about a system that doesn't require a roll.

Something that surprises me is that the benefit of a stiff furling boom seems under-appreciated. My boom furling shell has a large cross section and is made of carbon fiber so is not going to bend. This means that with a powerful hydraulic vang a traveler and end-boom sheeting don't serve the usual advantage of keeping the boom straight--though maybe there are other reasons to go that route that I don't know.

That's one of my favorite anchorages down that way. We've spent many nights just out of the lower edge of the frame.