sheet leads and hardware layout advice needed

Discussion in 'Multihulls' started by Charly, Aug 13, 2013.

  1. Charly
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    Charly Senior Member

    Hey guys, Once again I humbly seek some input from others here that are far more experienced than I am. I have several questions, and would appreciate answers to any of them. The study plans below show the beachcat I am building, and I am at the point that I need to make some more layout decisions.

    The dimensions of the boat are 36x22.5 feet, and I want to make it as easy to singlehand as is possible. With this goal in mind, any ideas or suggestions you have would be greatly appreciated.

    The first thing I am having trouble getting my head around is the headsail traveler arrangement. I have zero experience with this kind of setup and am not physically in a place that makes it easy to go and inspect other layouts.

    Question 1: Will I have to have a separate control line to the traveler car, or will the jib sheets alone move the car back and forth to where it needs to be?

    Question2:I am thinking that I would like to route the jib sheets to a turning block all the way outboard to a point just inside the stanchions, then aft to another turning block, then straight to the helm. Its a pretty good ways, but I had hoped to dispense with as many winches as I could (maybe even having only one on the whole boat, for the mainsail halyard.) So, will all this sheet length require extra purchase? Any advice on fairlead placement to avoid hockles? I might want to make up my own turning blocks to save money, and mount them permanently to the deck. Any ideas or leads on how to do that, and a good place to find the right sheaves, and what Diameter should the sheaves be? Any other problems I might have that I don't even know about yet:D?

    The other big thing is the daggerboard arrangement. The designer said that I don't really need a down-haul, but at the time in that conversation I had not emphasized that I want to be able to single-hand the thing. Where I live there are many winding creeks and lots of skinny water. There will be many instances when I need to pinch to weather, while fine tuning the daggerboard depth to get as much as I can possibly get- and all from the helm position. The big unknown here is how much force will it take to move the board- up or down, while under sail? Am I expecting too much? Any first hand experiences? How would I rig a downhaul if I wanted one?

    I guess that's enough rambling for now ( I haven't even mentioned the boomless main yet:)) Thanks for your inputs!
     

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  2. michael pierzga
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    michael pierzga Senior Member

  3. Richard Woods
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    Richard Woods Woods Designs

    Quick reply, more later

    You only need two winches to do everything providing you use stoppers.

    I suggest using daggerboard downhauls in part just to stop them banging in a seaway. I use a bow anchor roller carefully positioned as the first turning point in the uphaul line. That comes under quite high load as you raise the board (due to friction) usually it tends to jerk its way up. But otherwise there is little load. I'd use 8mm for the uphaul, 6mm for the downhaul as a minimum

    I wouldn't use a boomless mainsail as reefing can be difficult and dangerous. Also sail twist is hard to control and how do you hold the mainsail off the deck when its stowed?

    I doubt if it is cost effective to make your own blocks when you friendly ebay supplier can sell them to you cheap

    Richard Woods of Woods Designs

    www.sailingcatamarans.com
     
  4. catsketcher
    Joined: Mar 2006
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    catsketcher Senior Member

    A couple of thoughts

    Do you want a self tacking jib? You may like to look at the Seawind cats as they use a straight track for their jib track. As you say you are thinking about bringing the sheets aft it seems you may be thinking about normal sheeting arrangements.

    If you have a long sheeting arrangement I would consider something a little new. The problem with sheets running over the deck is that you can trip up on them and they chafe on the deck paint. If I was to build you cat I would consider running conduit as a toe rail and running the sheets aft through them. Real cheap and very effective.

    I have been considering making my own blocks as well. I did a bit of it on my cat and it worked well where a custom block was expensive. Also if I were building I would also try very hard to remove almost ALL fastenings in the deck - so a custom composite deck block glassed onto the deck will be cheaper, lighter, look nicer and never leak. Most blocks will be bought.

    On a boat like this you will spend a lot of time walking around. You should be able to drop the helm and pull the boards up or down. Even if you don't have an autopilot the helm can be dropped for 15 seconds whilst you pull a rope. As for loading on the board it is a function of sail loading. Put the sail area into a sail load calculator (search online) and the boards will make the same load. Whether they slide or not is up to your building.

    cheers

    Phil
     
  5. Charly
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    Charly Senior Member

    Hi catsketcher,
    I think a self tacker must be what the designer had in mind (but I am not sure). The hardware list calls for two blocks on the traveler and one on the clew. But I still don't really understand how it works.
    This photo show a Sea Wind with what appears to be that setup. I assume those lines that lead off to each side are the sheets, and are led aft in the normal manner? I was under the impression that with a self tacker one needs a curved track? I guess a curved track makes it better, but not necessary?

    So far I have composite chainplates, cleats, compression tube fittings, bow tube fittings and hatch hinges. I am trying my best to avoid any deck fastener perforations at all, though I know I will probably have to have some.
    I have thought of mounting blocks and such up on plywood pads, saturated with epoxy and covered and bonded to the deck, with the fasteners embedded in the ply but not down into the balsa part of the deck core, but I'm not sure if it would be worth it to have to grind the whole thing off to make any changes etc. Has anyone else done it that way?
     

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  6. Charly
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    Charly Senior Member

    I guess with a down haul, you would have to have the line attachment point on the board a little higher than the deck even when the board is fully down, which means the board would always stick up above the deck a ways, and ultimately the board would have to be constructed a little longer to compensate. That might be OK...OR, the turning block for the downhaul would have to be located somehow in the trunk and below decks... that seems like more of a headache.
    Also, with a down haul the board would be fixed in place and unable then to pop up out of the trunk. In my case I guess this wouldn't matter, as the whole crash arrangement/plan is dependant on foam crash blocks located aft of the board inside the trunk below the water line. But then I have zero experience with big daggers.

    The boomless main issue is driven by the desire for more headroom on deck. I want to have an awning fwd of the helm that covers the seat area, and be able to stand up straight. I am 5'11 and wanted to have about 6' clearance. By eliminating the boom, I can steal several more inches without raising the sail area. I guess it boils down to a compromise... either 1. a higher center of effort or 2. sail twist and more excitement when reefing, or 3. Bend over.:)

    I appreciate your comments.
     
  7. Charly
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    Charly Senior Member

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  8. bruceb
    Joined: Nov 2008
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    bruceb Senior Member

    Fun Cat

    Hi Charly, that should make for a fun charter cat. I live in Atlanta and know the area well. I have a 24' tri with a self tacking jib, tried a "single line" system on a straight traveler, but I couldn't get it to trim very well so I went back to a separate line for the traveler position.
    A few thoughts. A curved track will work with a single line system, but mounting it can be a problem for a "flat" track, and it is a hazard if the ends are raised. The extra line for the traveler is not loaded too high and can be a single led from the center. I would really anticipate fairly high sheet loads though. I have a 3/1 on my small (85 sq') jib, and it is all I can do to adjust it if the wind is over 15kts. You will end up needing a big (expensive and dangerous) multi part tackle on the clew, or find a way to lead it to your winch. It doesn't have to be adjusted very often on a cruiser. I had a boomless main when I got my boat and liked it a lot- it just didn't have enough area for racing. If you get the sheeting position to main foot length correct, they are really easy to handle, and jibes are a non-event. IMO perfect for your use.
    B
     
  9. bruceb
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    bruceb Senior Member

    more main

    I had lazyjacks and full battens on my boomless main. They held the sail when it was lowered. The sail was cut so the two lower "reef panels" and battens were the same length as the bottom of the sail. The tack was done with a downhaul tackle, and the clew had web loops and the mainsheet attached with a big shackle. Not the quickest to reef, but quite possible. A take up line can be led between the clew eye positions to help keep the sail under control while reefing. It worked pretty well, and was really simple.
    B
     
  10. cavalier mk2
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    cavalier mk2 Senior Member

    A wishbone boom would work too, giving the extra few inches but still having the control.

    Making blocks can save a ton of money using either aluminum or composite for the cheeks. a wood lathe can be used to turn the sheeve. I buy plastic round stock from commercial suppliers. Bearings can either be plain bronze or the appropriate ball bearing for sea use, again from industrial suppliers. Tooling is basic, jig or bandsaw, lathe and drill press. A metal working lathe would let you skip the drill press but while nice, isn't necessary.
     
  11. catsketcher
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    catsketcher Senior Member

    Yeah Cav - go the wishbone!

    Anyone who knows about my 38 footer knows I love my wishbone. It makes a cat heaps easier to sail as you don't have any problems with leech loading. I can easily singlehand my 38 footer so it could be considered if you want a soft foot. The only problem is that you have to go wishbone at the start of the build as you will need to get rid of the diamonds on the mast and have lowers instead (at least the lower diamonds have to go or the wishbone can't swing.) So you need to install some extra chainplates when building.

    So you get an easier to sail cat which is safer for your head and saves a bit of money in traveler hardware and winches.

    That being said - the main shape looks pretty old fashioned. Any sailmaker will make the head squarer so you will get enough extra sail area to raise the foot up a few inches without loss of area.

    As to the blocks - yes it is a pain to get the position wrong but the same will happen with all blocks as on any composite deck you must remove the core for every fitting. I like the composite block idea sometimes and am seriously considering it for my current build in the manner you describe.

    cheers

    Phil
     
  12. Charly
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    Charly Senior Member

    That is the way a sister ship is rigged (see photo) I was thinking I could also make a crutch out of the awning itself to help support the sail when furled.
     

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  13. Charly
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    Charly Senior Member

    I am thinking I want to stay with a straight track for simplicity sake if nothing else.

    This is what I am having trouble understanding... how would that be reeved (roven? routed?:))

    Thanks Bruce!
     
  14. Charly
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    Charly Senior Member

    When building your own blocks, does anyone have a good method for centering the hole for the pin? It seems that if you turn some acetal on a lathe, then you have to go back and drill out the hole for the pin, right? It seems to me that even with the cross marks made by the lathe chuck, and even with a drill press, cutting out the pin hole would be dicey to get the thing perfectly centered. Like throwing a pot on a potters wheel. The clay has to be perfectly centered or you will mess it up.

    Then maybe it wouldn't matter much, for a slow turning sheave. Anyone done this?

    edit: never mind. here is a good tutorial. http://www.duckworksmagazine.com/02/articles/woodenblocks/woodenblocks.htm
     

  15. bruceb
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    bruceb Senior Member

    traveler line

    On a small boat like mine, the line is just led to a strong bulls eye on center just in front of the mast but behind the track and then to the car. On a boat the size of yours, a modest set of sheaves would be better, and could be set up as 2x1. I will take a picture of mine this weekend. The line acts more as a "limit" line and can always be adjusted unloaded during a tack or by just heading up. The negative - The system works best if the jib cleat is part of the clew block assembly, which brings back the multi part block system. There are ways to get around it, including double sheets led to each side, but on a boat your size, the simplest might be a big beach cat mainsheet block system, complete with a cam cleat. I also tried running the sheet line to a center bulls eye, but there was too much friction and it tended to move the traveler car also. I was too cheap to install blocks. ;)
    I think the support for the boom would be a good addition, I sometimes use my bimini the same way. Many older cruising boats had a boom gallows, and they worked very well.
     
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