Latest News: Forums Technical Mainsheet location

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  • #4029
    Sungem
    Member

    Hi everyone, What is the advantage of the centre mainsheet location? I have the main located on the end of the boom currently but I was thinking of moving it. – As an aside- went out on the Crouch last Sunday, F7 with gusts. I was so impressed with the stability of the boat. We were nearly planing under jib alone 3 up – i kid you not! What awsome boats they are!

    #8725
    Colin Parkstone
    Participant

    Have a look at the item ” Centre Main” in the Technical Forum, may help some.
    C P 😉

    #8726
    Swiebertje
    Participant

    The “Center Main” thread Colin refers to, is all about a full center main. The disadvantage of this is that you can’t point as high as with a boom end sheeting arrangement. (And also it’s illegal for racing). The photo’s you will find if you follow the links given in that thread, clearly show how hard it is to sheet the boom in to a position above the transom corner. With boom end sheeting and a bridle we can sheet the boom in to a position almost above the center line of the boat.

    Most center main set ups keep the purchase at the boom end. Only the sheet end is led along the boom to a location above the thwart and from there down to a swiveled ratchet block and swiveling cleat. This arrangement is race legal since the main purchase is still at the boom end. Also all trim options are the same. This arrangement is just as good as a boom end sheeting as far as trim and pointing goes. It is only a matter of personal preference. And also, there is no need to double the purchase since the actual purchase stays ate the boom end. This means that the boom is less stressed. (See “Center Main” thread for explanation).

    A search on this forum should reveal some photo’s and more accurate descriptions of the latter set-up. Also there are several essays on the subject to be found on the WIT web-site: http://www.wayfarer-international.org/WIT/WITindex1.html

    The search function of this forum is found at the top of this page, just below where it says: “UKWA Forum” and “Wayfarer Association”.

    #8727
    Bob Harland
    Participant

    This reply is probably more from a cruising perspective;
    With the mainsheet tailed at the centre it is always to hand to adjust quickly – or free off in a gust.
    If you are hard on the wind in a breeze then you maybe trimming the main continually and it will not be cleated, but much of the time the mainsheet is cleated. So it’s important that you can free it off quickly. This is much easier with a centre sheeted main.

    A couple of disadvantages to this arrangement;
    The fittings for this tend to be a bit more expensive than a fully aft sheeted main. If you sail more than 2 up then the mainsheet does get in the way a bit

    there are some more mainsheet photos in the full article;
    http://wayfarer.org.uk/index.php?option=com_content&task=view&id=203&Itemid=140

    Hope that helps.

    #8728
    Colin Parkstone
    Participant

    Two ideas for your problems that MAY! help ?

    In the past it was not unheard of to have the last block before your hands to be on the boom and a block and cleat fitting is on the

    http://www.Harkenstore.com website.
    Big Bullet Blocks
    Item, 140 or 141

    Would free the cockpit somewhat!

    The other mainsheet I have seen fitted to a boat was started on the strop at the transom, led to the boom outer end block,along the inside of the boom to the gooseneck.

    Turned via a block down to the floor or heel of the mast then along the side of the centreboard box and then up to a centremain jammer that was adapted to have the sheet enter the jammer from below.This was set to one side of the centreboard box.

    Makes a hole below the waterline otherwise ? 😉

    This worked very well on a racing Albacore at the Worlds and the cockpit was very free to move up and down in.

    May help !!

    C P 🙂

    #8731
    Sungem
    Member

    Thanks to all for your comments. The long winter evenings allow time to think and tinker around with bits of string and block location etc! 😀

    #8756
    JoJo
    Member

    I am in the process of re-rigging my Mark 1 GRP – it has been stripped down for re- painting for too many years but finally has a new livery and I am trying to remember where everything goes back.

    I have a centre main block – but wonder whether the centre board casing is strong enough to support the pressure that this would exert.

    If not I shall rig with a rear main.either way; I also want to fit a bridle since the main traveller is past its useful life and I have removed it. I assume that I should screw two eyelets firmly to each side of the transom.

    I am looking forward to getting my Wayfarer back on the water in time for some spring cruising.

    #8760
    Swiebertje
    Participant

    @JoJo wrote:

    I have a centre main block – but wonder whether the centre board casing is strong enough to support the pressure that this would exert.

    Yes, assuming you use a triangular plywood block as shown here:
    These blocks are usually fitted with four (two on each side) self threading screws. The screws go in from bottom to top. These screws spread the load nicely. Provided you pre-drill the plywood block with the right size drill and the screws are sufficiently long, these self threaders will hold the block perfectly in place for many years. (Tip: Dip the screws in epoxy to strengthen the thread cut in to the wood). Note that the sides of the CB case are curved down, this shape provide stiffness and strength to the CB case.

    A stronger solution is to use a hollow plywood box that sits over the sides of the CB. Four small (4mm) bolts and (wing) nuts through the sides of the box and through the sides of the CB case to hold it in place. Because the box is hollow the main block and cleat swivel can also be bolted rather then screwed, as is the case with the massive block above. I think bolting is overkill and the screwed solution is adequate.
    @JoJo wrote:

    If not I shall rig with a rear main.either way; I also want to fit a bridle since the main traveller is past its useful life and I have removed it. I assume that I should screw two eyelets firmly to each side of the transom.

    If the rail is still good, leave it on and drill two horizontal holes through it. One between the screw at the end and the next screw, the other hole on the other side of the rail again between the last and the last but one screw. This nicely distributes the bridle load over the transom. Then use two large D-shackles, their pins go through the holes you just drilled, to tie the bridle to. Or lead the bridle through the shackles to a set of cleats on the inside of the gunwale, somewhere above the rear bulkhead. This allows you to adjust the bridle while sailing. Mind you, the latter is not really needed for cruising, not even for average racing. The old track also protects the transom from damage by the boom when the main is lowered in a breeze.

    If you can’t get the rail back on, you may have to re-enforce the inside of the transom prior to screwing the bridle eyes on it. I would probably use some hardwood made to fit and fix it in place with epoxy. If the hardwood is fully drenched in epoxy glue it is well protected from the elements as well.

    #8777
    JoJo
    Member

    Thankyou for some excellent and detailed advice – I shall look forward to getting this sorted . Are the plywood blocks as in the photograph available commercially anywhere or do I need to make one?

    #8781
    Swiebertje
    Participant

    They are easy to make by gluing three layers of standard 17 or 18 mm plywood together.

    Thomas Raun-Petersen stocks them ready for use. Thomas is the secretary of the Scandinavian Wayfarer Association and he also runs a little “Wayfarer special parts” shop from his garage. He may be participating in the Worlds (Weymouth) next year and if he shows up, I expect him to be there with his parts van. If you can’t wait that long, try his web shop: http://www.wt.dk/. shipping costs may be prohibitive though (weight).

    BTW, Thomas speak English very well and always finds the time to help a fellow Wayfarer sailor.

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