Forestay Tension on Dory

I am getting ready to rig my new dory and am not clear on how to tension the forestay. The manual is not clear on that point. It explains how to tension the shrouds with the lashings, stating those are "essentially permanent." The only hint on jibstay tension is the statement, "To take down the rig, loosen the jib halyard (italics mine) and unclip the [shroud] snap shackles." This implies that the jib luff sag is controlled entirely by the halyard, and that the forestay is laying completely slack in the hanks. This seems unconventional for a hank-on jib. Does the jib, as supplied by CLC have a wire luff that can take the tension? It wouldn't need any hanks in that case. If not, how is the sag controlled?

-Oscar

The Little Rascals.


14 replies:

« Previous Post       List of Posts       Next Post »

RE: Forestay Tension on Dory

The pirates seem to have taken over your boat :-) 

Nice picture, let me know what month you'll be entering it into the photo contest so I won't bother entering that month.

Laszlo

 

RE: Forestay Tension on Dory

   I had the same issues and called CLC for help.  Send me your email address and I'll send you photos of how I set up mine.

 

tim.broyer at gmail dot com

RE: Forestay Tension on Dory

The shrouds attach to the boat aft of the mast, therefore they are pulling the mast aft, which imparts tension to the (fixed length?) headstay. Sailing upwind with some mainsheet tension is also likely to increase headstay tension some, thus flatteneing the jib and making the boat point better, usually a good thing.

It's always a good idea to loosen a headsail halyard before easing the tension on the stay to which it is attached. If you don't, the full rig load is imparted to the luff of the sail. I'm confident the loads are pretty tiny in this case, and it would be difficult to build a jib luff that couldn't withstand whatever headstay tension this boat could generate, but it's still good practice not to ask your jib luff to stand in for your headstay.

RE: Forestay Tension on Dory

@nemoclad -- I understand the geometry. The question was specifically how to tension the headstay given the way the setup is described in the manual. There was no purchase/lashings on the headstay like the shrouds, and the shrouds are set up once (i.e., you don't tension them each time you step the mast). The manual implies the tensioning of the shrouds is via the jib halyard. That's my issue. Tim will be sending me pics (thanks Tim!) and I'll post them here

RE: Forestay Tension on Dory

   Oscar,  Thanks for raising this question.  I am also at a similar point in rigging my dory sloop rig, and was confused on how to attach the forestay wire.  Could you or Tim please post the pictures of the forestay rigging?

 

Attached is a picture of my dory, hopefuly this posting works since this is my first time using this forum.

RE: Forestay Tension on Dory

Try again with the image posting...

 

  

RE: Forestay Tension on Dory

Oscar,

Are you familiar with the lever action devices mounted on the front of dingy sailboats?  When in the up (loose) position, you can fine tune the tightness, then flop the lever over and it stays.  Dont know if I am envisioining your question correctly, but here is a link to some examples that can be mounted on the mast:

http://www.apsltd.com/c-6558-halyard-stay-highfield-and-other-levers.aspx

(Although these are not exactly like the one I had on my boats that had forestays)

RE: Forestay Tension on Dory

@Moonchaser -- Yes, a highfield lever would be a good solution. Thanks for that idea.

@Tom -- Nice looking Dory! Congrats. Nice work area too. I was stuck in a one car garage with tools and benches around the perimeter. I had 12" clearance on each side at the max beam point. I'm building a carport before the next boat. BTW, your dory was nice enough -- you didn't have to put extra weights on that benchpress bar to impress us...

Tim hasn't sent me any pics yet so I can't post his solution. However I think the highfield lever is the best solution. Maybe one of the CLC folks can chime in with their common solution.

RE: Forestay Tension on Dory

   Cosmonaut,

The benefit of those lever action devices is that you can stand in the boat behind the mast and lean a shoulder into the mast to hold it up while you easily mess with fine tuning the adjustment for the amount of jib tension you want.  I bet I have pernament marks in my shoulder from doing that every time I launched my Bucanneers but on our boats it will be very easy.  One thing, it will create downard load on the mast bottom, but in discussing mast load with John he has said multiple times that the boat bottom will handle it just fine as-is.  If you want to avoid scuff under the mast inside the mast step area you can slide a piece of linolium or thin wood into the mast step, but it's not too concerning for most people I think.

Curt

RE: Forestay Tension on Dory

   Curt and Oscar, Thanks for sharing the info on rigging gear and options.


Oscar, the weight set belongs to my younger son.  I could not even begin to budge that weight!  My son has come in very handy during the build, especially when I need to move or flip the boat.

 

I like using the outside covered deck area to build.  It helps to keep the sanding dust out of the house.

RE: Forestay Tension on Dory

>>>>This implies that the jib luff sag is controlled entirely by the halyard, and that the forestay is laying completely slack in the hanks. This seems unconventional for a hank-on jib.>>>

Correct; the intention is that jib luff tension is a matter of swaying hard on the halyard.  The jib has a rope luff stitched into it engineered for the loads, and it receives no support at all under sail from the forestay.  The forestay is needed only to support the mast when the jib is taken down.

The Northeaster Dory's jib is only 15 square feet (!) so tensioning devices like Highfield levers are absolutely unnecessary.  Anyone over the age of 10 will be able to muster the strength to give the jib luff sufficient tension with the halyard alone.  

I'm old enough to have been around during the period when racing dinghies transitioned from jibs hanked onto forestays, to jibs with luff wires that took the place of the forestay.  Most racing dinghies have a sturdy tackle hidden under the deck to adjust jib luff tension while under way.  These are much larger jibs, however, upwards of 40 square feet.

(I raced in a class that at first added a rule to the bylaws requiring a forestay, even though it had become vestigial.  We all just put a 1/16th-inch wire up there that flopped around loosely, doing nothing.  Because the mast was supported by a mast-bend-control widget at deck level, the forestay wasn't even necessary to hold the mast up when the jib was lowered.  I think they eventually did away with the forestay requirement.)

RE: Forestay Tension on Dory

   John,

sounds like you are describing the Snipe class in the 90's. We changed the rules to continue including a forestay - tha change was the forestay had to be tight enough so the mast did not touch the back of the mast partners w/o the jib rigged. This would keep the mast in the step in the case of a downwind capsize with the pole up and the jibhalyard relaxed. A mast that comes out of the step in a capsize can be very bad for the health of the boat!

Joel

RE: Forestay Tension on Dory

   Here's the rig Tim Broyer employed for tensioning the headstay. Presumably he tensions the lashing each time the mast is stepped.

TimBroyer

RE: Forestay Tension on Dory

It looks like Tim's forestay was a bit short. Perhaps there is a clip on the invisible end of the extra part, clipped to the foredeck.

The forestay prevents the mast from falling backwards. The shrouds prevents the mast from falling to the sides and from falling forewards. When sailing 1 shroud and the forestay keep the mast up, the second forestay (leeside) is idle.

Tension the forestay first, so that the mast has the right rake (backwards). Then tensions the shrouds to keep the mast vertical. You have to do this only once. No need for strong tension. There will be enough "slack" in the forestay to hook it up.

Ruud

 

« Previous Post     List of Posts     Next Post »


Please login or register to post a reply.