cost of in-boom furling?

[Balbas]

The average roller boom sail on a simple round boom gets steadily fuller as you reef: the luff rope either builds up a lump near the tack or slips down against the gooseneck, which does less harm to sail shape but can damage the luff itself.

It can work pretty well, but often doesn't, and to get a kicker on you either have to have a "reefing claw" that rubs the sailcloth or organise a wrapped-in strop, which again doesn't do the cloth much good. I've sailed a few boats with roller booms that worked well, but more that didn't.

I have a boom furling system on my longbow - made by some French company who's name I forget. It works surprisingly well, the only downsides (that I can see) being that

a) the rotation mechanism makes the boom stand an inch or so off the mast, so rather than pulling the sail up the mast track, there is a foil - approx. 1 inch which lives on the mast track. This then carries another track up which the main is hoist.

b) the kicker is non conventional. There is a wire strop run from one end of the boom to the other. At about 1/3 of it's length along (at the mast end), there is a SS ring, to which the kicker attaches. There's a swivel on both ends of the boom - to which this wire runs - so it always remains below the boom and doesn't cause any dramas with furling or reefing whatsoever.

My system is run back to the cockpit, so the reefing/furling process is:-
i) stick a turn of the (continuous) reefing line onto the coachroof winch and into the self tailer
ii) release both reefing line brakes
iii) ease the main halyard whilst winding in the reefing mechanism
with practice its simple enough to either reef or completely furl single handed. Note the lack of reefing pennants or requirement to go forward to the mast.

If I was specifying a replacement system I would probably go for a traditional slab reefing and a stack pack, but I don't think there's anything particularly wrong or inherently bad about the setup I've got. OK, sail shape might not be the absolute best at all times, but for a short handed sailor it's actually got some advantages imo.

 

[BrianH]

I fitted in-boom mainsail reefing to a relatively small - 9.4m/31' - boat eight years ago. The grounds were that I had experienced too many instant, strong gales in my area of the northern Adriatic that as a single-handed sailor I wanted a fast and foolproof reefing from the cockpit.

For a retro-fit, in-mast was out on the grounds of cost of a new mast and a friend's experience of a cheaper behind-the-mast system that was problematical. Besides, I had read that jams can occur, despite the many who claim not - or very rarely, and the thought of a jammed mainsail in a rapidly rising katabatic gale made me plumb for something that could always be dropped and lashed to the boom - once would be enough for me in a hurricane-force bora.

The first two years were a time of resolving minor problems by a sailmaker and Profurl agent, who just had too little experience - but now has. So much is critical to get right. The boom/mast angle must be precisely maintained by a rigid boom vang; the sail has to be quite flat and the luff cut in an 'S' form so that, as the sail rolls onto the boom-mandrel, the luff rope moves aft, then forward, in order to not pile up on itself.

The full length battens have to be at a precise angle to the luff so that they roll perfectly parallel to the boom. They have to be a precise length from each other dependent on the diameter of the rotating boom-mandrel, to not stack on top of each other and deform the rolled shape that could be larger than the inner dimension of the boom outer shell - as I had the smallest boom-shell available, this was a real possibility.

The reefing line and the halyard have to be hauled and freed in a controlled manner so that a modicum of tension was kept on the luff - too little and the sail descended too quickly and rolling was too loose. For this, an optional halyard brake where the line enters the mast is useful.

One thing soon became apparent, when reefing the mainsail had to be completely in-line with the wind - any wind in the sail will drive it forward to bunch up against the boom end and jam. To keep the sail totally without any wind in it is not always easy in a rising wind and seaway but critical to ensure that the mainsail is completely fluttering in line with the wind before starting to haul in the reefing line and, at the same time, keeping tension on the halyard to ensure a controlled drop. Only by following that principle rigidly can a smooth roll of the sail be induced into the boom. That does not need that the ship's head must be directly head-to-wind as the Profurl system uses an articulating luff with plenty of movement either side; it just means the mainsheet must be run out and the boom in-line with the wind.

One thing is clear: even with a small system, an electric winch would be a boon for raising the mainsail as the last few meters are hard going on the cockpit winch as all lines are led aft. The luff groove, probably because of the articulation, is a tight fit and introduces a lot of friction.

Would I fit again? Definitely, but I would shop around, knowing what I now know. The principle is clearly superior with all the benefits described by other posters above, and I think the development by all manufacturers has improved a lot over the past few years.

 

[thinwater]

Possibly a dumb question, since the answer is obvious, but that is how we learn....

Why are the sails not fitted with conventional reefing fittings, so that if the roller furling mechanism jams, they can still be slab reefed? My F-24 is fitted this way. I also like that I maintain outhaul control, even when reefed.

I assume the reason is rolling. The reinforced areas are bulky. It does seem that modern materials could resolve this for at least one fairly deep reef point. I gather the assumptions are that...
* It will never fail or jam.
* Drop the sail and motor home. This is going to be a little messy with some of the sail rolled and no lazy jacks or cover. Can the sail be sneaked out of the track and flaked on the boom, or is the bolt rope constrained? This latter problem could make it really fun in a breeze.

Not trying to bash the concept. I like it.

 

[Walusotu]

I have in-boom reefing on my Westerly Storm. I believe it is a SailTainer system (German) and has been on the boat since new (1989).
The more I use it, the more comfortable I feel but there are key areas which need attention which have been mentioned in previous posts.
1. Hoisting is generally no problem and not always sensitive to wind direction (obviously don't hoist with a following wind!)
2. The solid kicker must maintain the boom horizontal.
3. Lowering is critical. Head up to wind. Release tension on the mainsheet otherwise this puts the boom out of horizontal. Control the downhaul and halyard together so as not to let the sail drop out of control.
3. Most common problem has always been the snagging of full battens on entry into the slot caused largely by forgetting tension on the mainsheet or not heading up to wind.
4. Natural reefing points are at the various full batten levels.

Apart from this is an easy single handed operation. Sail shape seems OK. Sail condition is well protected in the slot using the sliding cover. Makes life easy for single handed cruising except when the procedure is not followed.