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Thread: boom vang for balance lug

  1. #1
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    Default boom vang for balance lug

    I'm not sure this is where to start but I'm having a few problems with my little tub and need some help. I have a 10 foot clinker built rigged with a balanced lug. The boat is owned by three of us and we use it at different times in the Gulf of Thailand and on the Andaman. Each of us tends to get it set up for our particular type of sailing. One fishes, another plays around near the beach. I like to go places. I need to boat to sail efficiently. The guy who fishes uses the little 2.5 engine a lot. Beach girl sails some, motors some, drinks too much beer, gets sunburned. I go to the islands off the coast with few to no people. Some of them are 70 km offshore. So I'm trying to get the most out of what I have available.

    The balanced lug was chosen by the original owner and builder. He is now deceased. The next owner kept the sail but changed the rigging. I was not sure about that until I found an old pic of the original set up. I know nothing about sailboat design or sail plans, but it looks like the old rig might have been better. The problem i have is that the boom lifts on a tack and I lose power. I can grab the boom with my hand, pull it down, and I feel like it's turbo charged. So from all the reading I've done it seem like a boom vang might be in order. Or maybe the old rig was better. It looked at lot simpler. For me that is a good thing. But it would involve a lot of drilling and filling and stuff. These are not my strong points. Plus it might require new hardware that I would not know where or how to to find with my limited Thai. I ask for ice cream and get noodles. Any suggestions would be appreciated. I got into a bit of a mess the last time I was out here and some kind soul came to my rescue. By the way, thank you for that. I was in quite a pickle.

    Pic r03 is the old rig. I never sailed it when it was rigged this way. The rest are as it is now. The boom attaches to the loop on the mast with a twisted shackle The mast is kept from rotating with the gizmo on the front (bowsprit?). As it is now, nothing keeps the boom from rising. The old rig looks like it might have done that. Ideally I would keep everything as close as I can to where it is now and still get a better sailing boat. The guy who fishes said he did not like the original rig as it got in the way of his fishing. I will be heading offshore about 40km soon and appreciate any suggestions. Its a long swim back in.

    gg
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  2. #2
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    Default Re: boom vang for balance lug

    There is a heap of info on setting up balanced lugs on this forum. There is a guide on Michal Storers web page, with links to here, and the valued knowledge from Keyhavenpotterer. Yes you do need a downhaul.
    https://www.storerboatplans.com/?s=tuning

  3. #3
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    Default Re: boom vang for balance lug

    Sweet little boat. Nice little swing beam roller trailer. If I was to make that boat go I would

    1. Not use the mast/ boom bracket. Its shown in racing that solid attachments between the boom and mast on a balanced lug sail make it slower.

    2. Instead use a 4:1 (minimum or 6:1 usually) downhaul on the forward end of the boom, between the boom and deck or mast. This tensions the luff and will give a narrower sail entry, like tension on the forestay on a bermudan. The limiter is more than 6:1/8:1 and all you do is stretch the sail, bend the mast or pull the bottom of the boat up without reinforcement in all of these structures.

    3. The boom section looks relatively thin compared to the mast. It might be that you need a thicker boom to stop it bending.

    4. Attatch a vang definately. This will stop you boom rising and avoid excessive tension on your mainsheet. It will also stop the sail luff becoming stretched and out of shape. Its simpist to have to small blocks of wood attached to the mast and boom and have a 4:1 tackle should be sufficient that can be slid over them when you are going to sail the boat.

    5. Since you've got a bit of a bowsprit there, you could attach shrouds to stop the mast bending. This will improve speed also. You can even build a lighter mast.

    6. If you get more serious, having the boom vang and downhaul led back allws on the fly adjustment, as well as the mainsail halyard allows you to drop the sail from a seated position.

    7. I'd have the foot of the sail closer attached to the boom and have a small cleat on the clew so that you can adjust the outhaul tension there and let it off after sailing.

    8. Given the bowsprit, and that bar accross the boat that might have taken jib sheets did it once have a jib? The lazyjacks might be using the jib halyard block? If so, then without it your sails center of effort will be a bit to far aft and will be giving weather helm. You can compensate for this without a jib, by canting the mast forward - bring the mast foot slightly aft to put the mast tip forward. This also gives power assistance to the sail moving outboard in very light winds which is a faster arrangement as it avoids oversheeting.

    9. The main halyard can be run from the yard attachement around the mast and down to the fore end of the yard. This gives a slightler better tension to the luff of the sail and usually a better set.

    10. At the sail's fore end of the yard, you rope band is perpedicular to the yard. Attach another rope band from this sail cringle that goes vertically inline with the luff to a metal eye, so that yard tension goes vertically down the luff.

    11. Thats a sweet little 10fter, round bilged with a displacement hull. I can the hull has been designed properly by someone. You want to sit most of the time up against the main thwart, just forward of the rollocks, so the stern doesn't immerse and slow you down, slightly further back in very high winds, probably on the thwart in very light air. You might need to make a longer tiller/ extension to enable this. When your sailing it, make sure the outboard isn't on the transom. It will stress the construction and put too much weight aft. Best secured around the daggerboard case area, or left on the beach.


    12. Thinking about the small boom section...there's a remote chance that it might have originally been a standing lug sail and your boom was a small sprit boom instead? They are much thinner section. That would make sense of the fixed metal mast fitting. You could rig it like that to vang the sail, and avoid a vang that will get in the fishermans way. Was it sprit standing lug with the sprit on the port side with a jib originally? At least that's what the spars may have been for, perhaps on another boat.
    Last edited by Edward Pearson; 11-29-2017 at 07:46 AM.

  4. #4
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    Default Re: boom vang for balance lug

    Issue # 105 of Small Craft Advisor shows a self-vanging mainsheet rig. The mainsheet fall is routed from the boom block to a turning block mounted on the aft side base of the mast, then back to the helm.

    Hope the voyage is a long one.
    May there be many a summer morning when,
    with what pleasure, what joy,
    you come into harbors seen for the first time...

    Ithaka, by Cavafy
    (Keeley - Sherrard translation)

  5. #5
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    Default Re: boom vang for balance lug

    That is a nice looking boat. Good advice Edward.

    I would want the boom boom to be able to freely rotate around the mast. Defeniantly look at Storer’s page on setup.

    I agree with Edward that the boom looks like it is undersized for balanced lug use. You need a good down haul, as stated above, attached to the boom close to the mast. This need to be set forcefully most of the time. This will exert a lot of force onto the boom right where you already have holes drilled in it for the hardware. I snapped an under built balanced lug boom that way once, granted it was in a heavy wind situation, it to had been drilled out at that spot on top of being too thin. My current boom is thicker in the middle and tappers to the ends for good strength at the down haul point and bend throughout to get the proper sail shape. There was a bit of trial and error here. Start thick sail test and keep planning down the boom until the the bend is correct.

    40-70 KM offshore. I would take an extra stick and a bunch of line with me for on the fly repairs. Are her flotation compartments watertight? Sounds like you guys have fun, that’s great to hear.

    Cheers
    Last edited by Matt young; 11-29-2017 at 12:02 PM.
    "Yeah, well, that's just, like your opinion man"
    -The Dude-

  6. #6
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    Default Re: boom vang for balance lug

    Have you tried pulling harder on the halyard?
    The yard and the boom are both canteleverd off the mast. Tension on the luff results in tension on the leech, both of which are effected by the halyard tension. Hoist harder, and see if your problems go away.
    SHC

  7. #7
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    Default Re: boom vang for balance lug

    That boom , combined with a loose foot, is not going to like vang loads.

  8. #8
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    Default Re: boom vang for balance lug

    Quote Originally Posted by SHClark View Post
    Have you tried pulling harder on the halyard?
    The yard and the boom are both canteleverd off the mast. Tension on the luff results in tension on the leech, both of which are effected by the halyard tension. Hoist harder, and see if your problems go away.
    SHC

    I agree this is the first course of action. If it's not enough, then the other suggestions should help -- especially replacing the hardware on the boom with a downhaul, 4:1 ought to do it. If the boom just bows out of shape when you tension things well up, then the boom needs to be stiffer. Just last winter I made up a new boom for my 75 sq. ft. balanced lug because the old one was too flexible.
    -Dave

  9. #9
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    Default Re: boom vang for balance lug

    Just shift the mainsheet back where it should be and set the sail as suggested above, there won't be any boom strength problems then.

  10. #10
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    Default Re: boom vang for balance lug

    The original photo I presume is the one with the boat on the water.
    Note the main sheet is attached to the boom about mid length.
    I presume the later picture is on the trailer, the mainsheet is at the end of the boom with a rope horse across the tiller.
    Have you sailed it with the mainsheet fastened to the middle of the boom, then via a block at the base of the mast. as posted by Sharpiefan.
    Give that a try and let us know how it goes.

  11. #11
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    Default Re: boom vang for balance lug

    A balanced lug has the downhaul about 1/6th or 1/7th the length of the boom back from the front end of the boom. The halyard is about 1/3 the length of the yard back from the front end of the yard. The sail is self-vanging and needs no additional vang. If the end of the boom rides up you can move the downhaul aft.

    A standing jug has a downhaul or sliding gooseneck at the front end of the boom. It is not self-vanging.

    Some people do not recommend balanced lugs on larger boats meant for open water because the lifting of the boom can provide a factor of safety in rough conditions. They say the boom end of a balanced lug can, in bad conditions, dig into the water.
    I will beg you for advice, your reply will be concise, and I will listen very nicely and then go out and do exactly what I want! (Apologies to Lerner and Lowe.)

  12. #12
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    Default Re: boom vang for balance lug

    I agree with the idea of reading up on Storer's research. I've tweaked several boats rigs now (though I am certainly no rigging expert), just using his principles & guidelines, with excellent improvement. My first thoughts are that I'd try to beef up that boom, and I'd try to stay away from adding a boom vang. And, yes, a solid downhaul is critical. You don't need hi-tech, hi-multiples of advantage. I won 4th in a national event with nothing more than a truckers hitch (2:1).
    David G
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    http://www.harborwoodworking.com/boat.html

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  13. #13
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    Default Re: boom vang for balance lug

    This is where things got to on the Solent. Dad spent years racing these things and this was his final version. He wanted simple, effective and neat controls.

    Mainsheet 4:1 using a auto Ratchmatic Harken main block on a bridle to reduce line length. With a center mainsheet you want a full section to the clew to reduce it bending up. Small carbo blocks with soft attatchments.

    [IMG]Keyhaven Scow 017 by keyhavenpotterer, on Flickr[/IMG]

    For the kicker...there's a 3:1 along side/ hidden under the centercase iroko top trim led back to a Harken cleat.

    [IMG]Keyhaven Scow 010 by keyhavenpotterer, on Flickr[/IMG]

    that transfers to thin dyneema to run through Harken Micro ballbearing blocks (dad didn't get around to splicing them which would be better).

    [IMG]Keyhaven Scow 011 by keyhavenpotterer, on Flickr[/IMG]

    The blocks attach to the bolts that hold the case sides to the thwart.


    [IMG]Keyhaven Scow 009 by keyhavenpotterer, on Flickr[/IMG]

    Then down and up from the mast foot to the boom and back. A 2:1 plus a 3:1 to get a 6:1 with a few cheap Micro blocks.

    The one design sail is tracked onto the yard and boom. Bottom of the sail is built with a shelf. The luff is reinforced as you can see.

    [IMG]
    Keyhaven Scow 007 by keyhavenpotterer, on Flickr[/IMG]

    Same deal the other side, but it runs to the kicker. uses a 2:1 along the centercase and a 2:1 upto the kicker to give a 4:1.
    Last edited by Edward Pearson; 11-30-2017 at 10:30 AM.

  14. #14
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    Default Re: boom vang for balance lug

    [IMG]Keyhaven Scow 012 by keyhavenpotterer, on Flickr[/IMG]

    Looking for the main halyard...well Dad never needed to reef it...the main halyard is actually led forward to the stem and is the forestay. It has a simple clip on it which when the yard is at the right height just clipped onto the stem fitting with a line led back to the cleat when it was let go after pulling the boat out to drop the sail and spars back. All luff tension from the bottom downhaul. Dyneema shrouds easy to set up and don;t scratch your boat but one chafed through once...carbon spars were very light, about half aluminium before all the hardware and fittings which reduces the advantage but needed to be stiffer for the one design sail.

    Cocoon cover to stop the topsides fading.

    [IMG]Keyhaven Scow 001 by keyhavenpotterer, on Flickr[/IMG]

  15. #15
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    Default Re: boom vang for balance lug

    I thought those sails were set loose footed, or have i seen pictures of both? Nice set up. How many dinghies in that park?

  16. #16
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    Default Re: boom vang for balance lug

    Interesting how people see things differently.
    The clue of the person altering the rig to make life easier for fishing to me means taking the main sheet off the boom end and altering the tack so the outboard end sits higher. That says to me the first photo on the trailer is the unaltered rig, the one that looks right.
    The downhaul doesn't exist because it has a rigid fixed point on the boom, like a gooseneck for lug.
    So just put it back to what was, pull some halyard on and go sailing.
    That bowsprit is there for a reason, there should be a reacher with the boat, which would be helpful in the light.

  17. #17
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    Default Re: boom vang for balance lug

    There's maybe 100 plus another 100 in the boatyard/ other dinghy clubs.


  18. #18
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    Default Re: boom vang for balance lug

    Just to be clear, this is pic r03:



    ...which looks much better. It might help to pull the tack right down to the forward end of the boom, as shown in that picture. With as much sail forward of the mast as r03 shows, the rig should be self-vanging, as long as there's plenty of tension on the luff.

  19. #19
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    Default Re: boom vang for balance lug

    Pic r03: The halyard tie off point is too far aft and should be moved forward on the yard, which will also make the luff more parallel to the mast, which it should be, as well as lower the clew. I can't say I'm thrilled with mid-boom sheeting on a boom which is so skinny. Sheeting hard is going to bend the boom a lot, which will then move the tack and clew corners of the sail closer together - which will then increase the sails draft, which is the opposite of what you want to happen when sheeting in hard. No vang is needed, and a gooseneck on a balanced lug is kind of counter productive. Something which can slide and uses a downhaul would be a better bet.

  20. #20
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    Default Re: boom vang for balance lug

    Hi guys,

    Thank you all for such a treasure of information. I got tangled up with a bit of not so fresh food stand squid and went down for the count, literally passing out at a stop light and falling off my motor scooter. Thankfully no one wanted to mess up the bottom of their car running over the scooter, so I survived if a bit weary from the experience. BTW, I had not had a thing to drink, which might have been part of the problem. When I was traveling in S. America I took a slug of pure grain and ate a lemon before diving in to street food, and I was never once sick; a little wobbly perhaps, but never sick. Perhaps it's a ritual worth reviving.

    I will have to put on my best Jethrine Bodine thinking hat and do a little ciphering. This is all a bit complicated for someone with limited tech chops, so I will probably start with the most simple suggestion and try to find the best solution with what I have on hand. Hardware is hard to come by here in the sticks, and outrageously expensive when available.

    Again, thank you so much. I should back on the water in a few days. I will likely have a few questions.

    Gwen

  21. #21
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    Default Re: boom vang for balance lug

    Glad to hear you're all right! I hope we've been of some help.

  22. #22
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    Default Re: boom vang for balance lug

    Hi guys,

    After fitful trial and error I am back to point one. I saw in a pic on one of the links provided what looks to be the rig that would let the boat point and perform better (see attachment). If this were my boat, and mine alone, I think this is what I would try. But it's not, so I must proceed to plan B, or C. Both my partners like the boom being secured to the mast with the twisted shackle. It's simple and easy with no adjustment. I cannot change their minds on this, so I am stuck with it. As one of the replies mentioned, the boom vang that I rigged from mid boom to the base of the mast was a bit clunky, possibly due to my lack of hardware to make it more user friendly. My fishing partner knows something of sailing and understands my predicament, but he does not want the original rig (in the pic of the boat on the trailer) because his fishing rods get tangled up in it. His advice is to keep using my bicep. But sometimes I spend a day or two at sea before reaching my destination. My bicep is toast after about an hour.

    Another comment was to remove the engine from the stern and store in forward. I frequently sail in meter seas. When I need that little engine to run to the lee of some island, I really need it. I can not imagine trying to drag it aft and get it secured in the types of weather where it is my lifeline. From a balance standpoint, because I am frequently out for days at a time, I carry 20 gallons of water forward. The heft of the 18 kg motor is balanced against 75 kg of water carried forward, so the boat does not sit low in the stern. Fisherman partner says the boat was constructed to carry the motor weight. We'll see. If the transom cracks off one day I will have to man the lifeboat.

    I may have presented an impossible task to this knowledgeable tribe. A rigger I spoke with in Phuket, way out of my league in terms of price, said I needed to chunk all the wood stuff and use aluminum instead. He could build a rig that could be changed easily to suit the user. Even if I had the substantial sum required, more than was paid for the boat, both of my co-owners nixed the trashing of aesthetically pleasing wood for metal.

    It may be impossible to counter partners' objections and come up with a better sailing boat. The situation reminds me of one I endured with a battle ax mother-in-law. But, unlike the mother-in-law, I'm stuck with my partners until a winning lottery ticket drops in my lap.

    I want to thank all of the people here for the assistance that they have provided. I lost a mast some months ago in weather that moved in quickly and several here came to the rescue with suggestions. We have a new mast that a local fisherman hand carved from a piece of mai dang. It is 6 kg heavier than the mahogany mast but the water I keep aboard has solved the potential higher cg problem mentioned by one forum respondent. It is supposed to be much stronger too.

    Gwen

    Bruce-DSCF0415-560x419.jpg

  23. #23
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    Default Re: boom vang for balance lug

    If you can do nothing else, make sure the tack is located as far forward as possible, as in picture r03.

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