Roller reefing boom

Discussion in 'Boat Design' started by Steve W, Apr 4, 2009.

  1. Steve W
    Joined: Jul 2004
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    Steve W Senior Member

    Im building a roller reefing/furling boom for my Lindenberg 26 and have a couple of ways of dealing with the goosneck end. Im leaning toward using a shaft running thru the mast with a crank handle on the front,this is the system used on the Corsair trimarans and apparently works well as they have continued using it over the years.I believe the Albin Vega also uses a shaft thru the mast although i have never seen one. My only reservation is drilling a fairly large (3/4") thru the mast in an area that takes a lot of fwd loading from the vang, i cant help thinking that it must weaken the mast somewhat but then it seems to work fine on the boats that use this system,i dont hear of Corsairs breaking masts at the goosneck.So am i worrying about nothing?
    Steve.
     
  2. tom28571
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    tom28571 Senior Member

    Why do you want to use roller reefing on the mainsail boom?

    You may accept this as one vote against roller reefing of any kind on a boom. It's inferior to slab or jiffy reefing in performance, mechanical complexity and ease of operation. A Lindenberg 26 is a great racing boat.
     
  3. rwatson
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    rwatson Senior Member

    Big holes in the mast should always come with an engineering opinion , especially in aluminium - in my opinion..

    I would be more inclined to think of some kind of simple wheel that could be wound down by a winch like the main halyard. Some sort of smallish diameter wheel between the boom and the mast, that could be manually hand turned if needs be.

    I would have to hear some pretty detailed reasons to be convinced that roller reefing is such a bad idea. I would rather be up the non-thrashing end of the boom getting sail in than negotiating reefing points all along the boom in rough weather. I know the skipper *promised* to keep the boat head to wind .....

    But hey - there may be more to it than that
     
  4. tom28571
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    tom28571 Senior Member

    You just gave one of the best reasons. Unless someone is at the thrashing end of the boom, you will have a too-full and very poorly shaped sail with roller reefing. Reefing usually occurs when the wind gets higher and if you have been at that thrashing end very much, you will know what I mean. Like missing teeth and bruises or worse. Most people tie in reef points only if the reef is going to be taken in for a long time. In shorter races, for instance no one ties the reef points. With a properly set up boat, a slab reef can be completed in about 30 seconds. Then tie the points later if you want to.

    Boom vangs are difficult to provide with roller reefing. Not impossible but difficult. Foot outhauls are also difficult. Battens should be aligned horizontally to avoid warping or breakage. Mansheets on the center of the boom are not possible on roller reefing booms.

    There may be other factors but this is enough for now.
     
  5. Steve W
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    Steve W Senior Member

    Tom,i have owned many boats over 35 years and ive always had slab reefing including single line systems and have no problem with the reefing aspect, however when it comes to putting the sail to bed at the end of the day its a pita,you either have slugs and have to flake it or you have a bolt rope and you have to roll it up alongside the boom,either way its a 2 person job to do it neatly in any kind of breeze.I raced a season on an f27 years ago with a roller boom and it was awesome,with a full batten main you just roll it down to a batten to reef and the batten takes care of the foot tension,its very easy to do,you just stand at the mast with the halyard in one hand and crank with the other and you get a nice roll and its much quicker,easier and neater for furling which is the most important thing to me,after all,i furl the sail much more often than i reef it.The sail ends up rolled very neatly on the boom,which is better for the sail than flaked and no need for lazyjacks.
    The only issues i see are that i need to disconnect the vang when i roll in a reef but ive got that figured out.What i intend to do is use a double vang/preventer system where i have a 4:1 tackle each side which attatch to the boom with a common snapshackle with a webbing strop around the boom and the other end attatching to the toerail near the shrouds,the line will be endless and run back to the cockpit behind the helmsman,this will give a great deal of control over the leach as well as being able to act as a preventer. For reefing i will have dedicated reef positions with luff and leach cringles just like for slab reefing in case i want to reset the outhaul once reefed ,i will also have a reinforced patch with a slit in it just under the full length batten where i can re feed the webbing strop and re attatch the vang when reefed,the vang will be pulling down and out instead of down and foreward in he usual manner so it wont be trying to tear the sail.
    rwatson, i just looked at an F31 a couple of days ago and they have a 3/4" hole thru the mast with a fairly thin ss plate bent around the front and back rivetted on to prevent the shaft wearing the hole and thats it,i will probably talk to a sparmaker for peace of mind.As i see it all these new in boom furling systems are just the same thing only they have a huge,heavy boom around the outside which deals with 4 issues.
    1/ they can have a solid vang which
    2/eliminates the need for a topping lift and
    3/allows for the mainsheet to be attatched anywhere on the boom and
    4/covers the sail when its furled.
    They still have to have a mandrel to furl the sail around and they still have the holes thru the mast,im not sure how much they adjust the vang as the boom to mast angle is very critical to the sail furling properly.
    I was going to use a line drive drum at the gooseneck but the problemis that the tack would end up 4-5" aft of the mast so i may have a problem feeding the boltrope into the track so would probably need to go thru a prefeeder and then enter the track 3-4ft above the boom which i think would work fine.With the shaft thru the mast the tack is only about 3/4" behind the mast and will line up fine,i will still use a prefeeder.
    With all these in boom systems the tack is so far aft that they have to have another track spaced back maybe 4" behind the mast track.We installed a profurl system on a Nimble 30 some years ago and it was about $7000. Im doing mine out of the parts bin.
    Steve.
     
  6. tom28571
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    tom28571 Senior Member

    Yes Steve, the magic word is full length battens but very few boats have them. Converting to full battens on a boat with the usual mast rigging can be a problem since the battens hold the roach out and hang up on the backstay unless there is a fair amount of wind. My son has a Farrier 24 and it does work pretty well but I still much prefer slab reefing on most boats. The cost is a big issue. Slab reefing can be put together with a few bucks while roller is either very expensive or requires a lot of know how that many sailors don't have. The first thing I have done when buying a boat with a bolt rope luff is to have slugs put on the main. It is a bit of a nuisance, but that is at the dock and on the water they work fine.

    I did put a couple full battens on a S2 7.9 to get a few more years racing out of an old main. That worked ok but in light air we had to do a flip on the boom with each tack. Several crew got banged noggins even with warnings.

    Most anything can be worked out if there is enough money but some of these boom , batten and car rigs cost more than all my boats put together. In buoy racing, I used to reef and unreef the main on a 22 and a 25 footer on every lap.

    Still there is room for personal preference and I wanted to point out some of what I consider disadvantages of roller reefing because, on the surface, it sounds so easy.
     
  7. Steve W
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    Steve W Senior Member

    Hi Tom,you are right,full battens are an important part of making the system work.The Gougeon brothers have been using roller reefing and furling on all their boats for decades and will be doing it again on the new cat they are building now but they are all multihulls with full battens.I plan on setting my boom up so that i can tie in a new tack and clew if it looks like the reef will be in for a while.I must stress that i do not intend to race this boat,im trying to make it convenient to go for a sail on a whim and i want the main to be as easy to set and strike as the headsail which is on a Harken roller furler.
    Now im not really a fan of headsail furlers but this one came with the boat.
    Cost is not an issue as i am a boatbuilder and you tend to accumalate stuff over the years and i would be suprised if i end up with $50 in this boom, i would have a lot more in a conventional boom when you add up all the blocks,line,cleats and/or clutches it would take to set up for 2 reefs and lazy jacks.
    Next time you are at your sons boat have a look at the boom,it is exceptionally simple,there is no part a reasonably handy boat owner couldnt fabricate. Oh,if you get the chance would you mind measuring what diameter the thru the mast shaft is,i just looked at an F31 and its is 3/4" but it has a huge sail and lots of stability,im wondering if it is smaller on the F24.
    Another reason to do this is that i love thinking things thru and making it work,another boat i have is a 1980 C&C24 which i took as a work trade with no rig so i picked up a used J24 rig and redesigned and enginered the boat to use that,ive never been a fan of C&Cs but this is a sweet sailing little boat.
    Steve.
     
  8. tom28571
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    tom28571 Senior Member

    Steve,

    You sound like you have a handle on all the issues. The C&C24 is a great little boat that can be had for not so much money. It should be better than the J24 for short handed sailing. The last time I looked a battens and batten cars, the price scared me, but I guess that on a 24 footer, you don't really have to have the cars. How will you handle the backstay issue. Surely the mainsail overlaps it some. Making these arguments from a computer and old memories is not like being there. Best of luck to you. I also get a charge out of making old discarded stuff work. While I raced seriously, I refuse to dip into the family budget for boats, which helps maintain good relations with SWMBO.

    I finally got tired of the old beat up mainsail on the S2 7.9 and bought a used one and a genny from a competitor who just bought a new high tech set of sails. The finishing order remained the same. Sometimes the gods smile.
     

  9. diwebb
    Joined: Jun 2008
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    diwebb Senior Member

    Hi Steve,
    I have sailed on two boats about 35 years ago with through the mast boom furling systems. The first was a charter boat, an Albin Ballad if I remember correctly, that my sailing club chartered for a cross channel cruise from Poole in Dorset to Brittany in France. The system worked extremly well and was very convenient for furling the sail. The second was my own boat which had a luff groove main in a wooden mast. The system also worked well here. The vang problem is quite easy to work. Use a 5mm thick stainless hook about 100mm wide with a fixed length stay to the outer boom end and a standard vang attached. The hook should be shaped to go around the boom and reefed sail and then kick back underneath the boom almost like a question mark. To reef or furl the sail just loosen the vang and wind away. Once reefed then tighten up on the vang. All of the vang force will be downwards as the tie to the boom end will take the forward force. You can also pad the hook with leather to save sail chafe.
    I hope it all works out well
    All the best.
    David
     
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