Proper forestay tension and mast angle

Moderator: GreenLake

Proper forestay tension and mast angle

Postby zeroready » Mon Dec 21, 2020 9:13 am

Thanks! I'm in key west so every day is sailing day! So I dismasted a couple months ago when a shroud snapped at the turnbuckle and replaced all three stays and had to cut a bit off the bottom section of the mast where the tabernacle ripped out of it. I shimmed the bottom of the mast up an inch and a half to make up for what I cut off. All that is to say I'm still playing with the tension of the stays. I've read the discussion here about being able to strum them when trying to figure out how tight to set them. Now here is where I am at. When I raise the mast and secure the forestay I have to wrap a prusik around it so I can get enough purchase so I can pull it down the last couple inches against the shrouds to secure it in the stem head. The forestay is tight and I can strum it. I think what you're seeing with the downhaul is due to the way its fastened to the stay above the top hank. It's a beefy snap hook tied with a figure 8.

Image

So the reason the downhaul is going out away from the stay at the top is just the hook sitting horizontal on top of the hank. I believe.

Now I'm still not sure if my stays are tensioned properly or not. Should I really have to pull down with most of weight on the forestay to get it the last couple inches down to to the stem head? Is that too tight? When close hauled and sheeted in the leeward shroud loosens and the windward is tight.

Here is my real concern. When I cut off small pieces of the mast to install the new tabernacle, I'm worried I didn't cut the angle right. Because before with the old tabernacle when I raised the mast it would sort of naturally lean forward and pull against the shrouds. Now when I raise it and attach the pins in the tabernacle if I were to just let it go before I connect the forestay it would fall backward. I'm thinking I need to change the angle of the cut very slightly and reattach the tabernacle to have the mast at the right angle.
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Re: Glorious sunset by myself today

Postby GreenLake » Mon Dec 21, 2020 7:29 pm

What you describe is temporary (or should be temporary) while you raise the mast. The actual position (angle) will absolutely be determined by the lengths of the shrouds/forestay.

Under the assumption that you shimmed your mast exactly to where the shroud attachments are at the same place as before, the new ones should precisely match the old ones. If they don't, the mast position would be altered.

Now, a properly rigged DS has positive mast rake (the mast leans aft just a bit). So, what you describe seems to be better than what you had. It sounds like your shrouds were too long before. Also, the amount of force you describe seems not too much. When you go sailing, the leeward shroud should not be slack until you hit about 10 knots of wind. Above that, it will be noticeably slack on a DS.

The "note" I strum is the on the shrouds, not forestay (I don't know that the forestay would sound, I can't reach it while tightening my mast jack).

Some people with a tabernacle mast fit a Highfield lever on the forestay.


PS: I'll move the tail end of this thread (your last post and all replies) to a new topic in "rigging" as it doesn't seem to be about where to cruise but how to step the mast.
~ green ~ lake ~ ~
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Re: Proper forestay tension and mast angle

Postby tomodda » Mon Dec 21, 2020 10:18 pm

For what it's worth, I do have a tabernacle, the old fashioned type, and a central jack nut so all 3 stays get tensioned together. It has one hinge in the back and fits over a vertical pin at the front. No turnbuckles. I've learned to put a washer over the vertical pin to rake my mast a bit and tension my forestay nicely. If I expect strong winds, then two washers. When I remember, of course!
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Re: Glorious sunset by myself today

Postby zeroready » Mon Dec 21, 2020 11:38 pm

GreenLake wrote:What you describe is temporary (or should be temporary) while you raise the mast. The actual position (angle) will absolutely be determined by the lengths of the shrouds/forestay.

Under the assumption that you shimmed your mast exactly to where the shroud attachments are at the same place as before, the new ones should precisely match the old ones. If they don't, the mast position would be altered.

Now, a properly rigged DS has positive mast rake (the mast leans aft just a bit). So, what you describe seems to be better than what you had. It sounds like your shrouds were too long before. Also, the amount of force you describe seems not too much. When you go sailing, the leeward shroud should not be slack until you hit about 10 knots of wind. Above that, it will be noticeably slack on a DS.

The "note" I strum is the on the shrouds, not forestay (I don't know that the forestay would sound, I can't reach it while tightening my mast jack).

Some people with a tabernacle mast fit a Highfield lever on the forestay.


PS: I'll move the tail end of this thread (your last post and all replies) to a new topic in "rigging" as it doesn't seem to be about where to cruise but how to step the mast.


That sounds great, I'm glad I don't have to recut the mast I wasn't looking forward to that. I mean she sails really smooth now so I was hoping that I'd somehow gotten everything right when installing all the new rigging. With all my recent improvements (new standing and running rigging, tiller clutch, jib downhaul, topping lift, self righting beverage holder, fishing rod holder) it's just become an absolute joy to sail. Singlehanding is no problem now with the tiller clutch. When the wind calms down in my backyard a bit I'm going to hoist the spinnaker for the first time and start getting that figured out. Thanks for all the help!
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Re: Proper forestay tension and mast angle

Postby GreenLake » Mon Dec 21, 2020 11:57 pm

Go look at the measurements described in the Tuning guides (should be in a parallel thread). That would tell you whether you got your standing rigging set up to where the mast is in the right position. (Correct rake). Although, just taking out the boat, under 10 knots going upwind should not require hauling on the tiller to keep the bow from rounding up - stronger winds, and heeled, is a different matter, some definite weather helm expected. Also, make sure that you don't have lee helm, even in light winds, and that should reassure you that the mast rake is in the ballpark.
~ green ~ lake ~ ~
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Re: Proper forestay tension and mast angle

Postby Shagbark » Tue Dec 22, 2020 6:41 pm

I use a highfield lever purchased from Rudy. LOVE IT. Makes raising the mast so much easier and I know I got the tension on the forestay without all the fighting of the rigging that I was doing before. Probably one of the better investments I've made on my DS.
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Re: Proper forestay tension and mast angle

Postby zeroready » Tue Dec 22, 2020 11:19 pm

Shagbark wrote:I use a highfield lever purchased from Rudy. LOVE IT. Makes raising the mast so much easier and I know I got the tension on the forestay without all the fighting of the rigging that I was doing before. Probably one of the better investments I've made on my DS.


I'm intrigued! So with the Highfield lever, I could connect the forestay to the stemhead with the stay a little slack, then lever it tight?
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Re: Proper forestay tension and mast angle

Postby tomodda » Tue Dec 22, 2020 11:57 pm

I have a tabernacle, making my life a bit easier. What I do is I connect my jib halyard to the stem head (mine has three holes) and pull the halyard to help me get the mast up. Once it's in place, I tension the halyard as much as I can (by hand is fine) and tie it off, which holds the mast up while I attach the forestay. There's usually enough tension on the hslyard to allow me to easily slot the forestay home. If not, I can just push on the forestay a bit with my elbow (like tensioning a bow) to get me that last inch of slack on the forestay so I can connect it. Works for me, no lever needed. YMMV....
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Re: Proper forestay tension and mast angle

Postby GreenLake » Wed Dec 23, 2020 12:51 am

zeroready wrote:I'm intrigued! So with the Highfield lever, I could connect the forestay to the stemhead with the stay a little slack, then lever it tight?


That's the idea. (I have another boat with a deck stepped mast, but it has the jib on a furler, so I can't use a lever and have to use Tom's method with the halyard).

My DS has a keel-stepped mast with mast jack, to that's an entirely different setup, so I'm a bit second-hand here.
~ green ~ lake ~ ~
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Re: Proper forestay tension and mast angle

Postby Fly4rfun » Wed Dec 23, 2020 1:48 am

been considering one of them, I have the 3/32 stays, and from what i read should upgrade to 1/8th in. right now i use a ratchet strap with one end in the mouth of the luft opening on the mast and one of the holes on the stemhead to get it tensioned to attached the forestay . not sure i want to expend the money for the lever when i could use the tie down strap.
"Sail Aweigh" 1966 DS1 #2675
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Re: Proper forestay tension and mast angle

Postby Shagbark » Wed Dec 23, 2020 2:21 am

I went with the lever forestay when I upgraded from the 3/32 to the 1/8 rigging. I believe it added about $40. I do something similar as tomodda but I attach my halyard to my trailer (the part that raises vertically and meets the bow) to assist in raising my mast. Prior to the lever, I found I was still fighting the forestay while trying to get the pin in the stemhead. Not any more!
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Re: Proper forestay tension and mast angle

Postby tomodda » Wed Dec 23, 2020 9:27 am

How does the lever interact with hanking on the jib? It looks to me as if it would interfere with the bottom hank or two.
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Re: Proper forestay tension and mast angle

Postby Shagbark » Wed Dec 23, 2020 11:38 am

Lever has no interference with the jib. The lever is only 6.5 inches long when collapsed, so as long as the first hank is above the stemhead by that, there should be no problem. If people aren't in the market to upgrade their rigging, maybe there is not much advantage in buying the lever. However, if they are looking at upgrading, I think its well worth the dollars. I try to cut every minute of rigging time that I can. If the lever even saves me 1 minute of struggling with the forestay, its worth it. If I use the lever, say 150 times over its life, that saves me 150 minutes on the ramp, or 2.5 hours of additional sail time! I'd gladly pay the $40 for 2.5 hours of sailing and less struggling.
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Re: Proper forestay tension and mast angle

Postby GreenLake » Thu Dec 24, 2020 1:50 am

I like that line of thinking.

I used to do unnecessary steps in rigging. No more. Anutime something can be cut out, it will - however, I'll add something if it brings new functionality.
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Re: Proper forestay tension and mast angle

Postby Fly4rfun » Thu Dec 24, 2020 2:09 am

would you not want the foot of the jib to be closer than the 6.5 in above the deck? could you place the first one close to the attachment location, the second seems to me would attach above the lever.
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