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Weyalan · 16-12-2013, 16:55

After much thought I'm still in a quandary about how best to attach an inner forestay to the mast.

The inner forestay will, most likely, be Dyneema or Amsteel or something like that, designed to be stowed at the base of the mast and pulled out and tensioned to carry a hank-on heavy weather jib or storm jib.

The mast is a rather skinny section 3/4 fractional with two sets of in-line spreaders and jumper-struts & diamond stays to support the top mast (typical IOR 1-ton fractional rig). The plan is to try to locate the mast attachment for the top of the stay just below the forestay attachment, so the line of the inner stay intersects where the running backstays attach to the mast.... this will probably work out to be 250-300mm (10"-12") below the current forestay.

There are 3 options under consideration for attaching this inner stay:

1. T-ball fitting
Using a T-ball fitting, such as attaches shrouds to the mast would be the simplest solution, but I am concerned that the load will not be well enough spread and could cause localised damage/failure (bearing in mind this stay will be used primarily for heavy winds or severe winds). A mast rigger and a sailmaker have both offered this solution, but neither of them have any real vested interest in keeping my mast pointing upwards.

2. Collar and rivets
A stainless steel collar that goes approximately 3/4 of the way around the mast (allowing for the mainsail), attached with (Monel) rivets is probably a pretty common solution (it is how our forestay attaches). I am slightly concerned about putting several hoses in the mast, for rivets (probably around 10 or 12 in all) on what is already a fairly skinny mast.

3. Collar and through-bolt
Similar collar to the above but with a single, large bolt right through the mast, with a tube on it to prevent mast compression. My father-in-law's Adams 40 has a solent stay attached by this method.

The more I think about it, the more prevaricatory I become. I can see advantages and disadvantages to each. Which would you go for, and why?

ozskipper · 16-12-2013, 17:19

As your boat is a Vanderstat, I will assume its steel. So you shouldnt have any issues at deck level. But on the off chance she is one of the rarer glass vanders, I think the bigger problem would be how to distribute the load at deck level.

I would rather use the 3rd and strongest option. As you suggest, it will be used for storm sails. However they are quite small! Compared to a full size genny in 15 knots- the loads probably arent that much different. (someone smarter than me will know)

Then again, without cynicism, the rigger who suggested option one knows more about it that both of us I would think. He knows he can go to jail if he work kills someone- just like the rest of us. So I think he does want your mast to stay up

Weyalan · 16-12-2013, 17:35

Thanks for the comments. For the record it is a glass and Kevlar Vandestadt. I plan to fit a stay below deck, between the underside of the deck (and deck fitting for the innner stay) down to the hull to prevent bad things happening to unsupported loads at deck level. There is a ring frame at a convenient location to assist in achieving this goal.

**Jim Cate** · 17-12-2013, 23:32

Patrick, while I'm not a true believer in T-ball terminals, my mast uses them and has survived for a lot of miles.

In your case, consider the relative loads from the storm jib/inner stay and your shrouds. I suspect without factual knowledge that the shrouds take much larger loads (much larger wires required) and their T-balls have survived. I suspect that a well done T-ball would be just fine, and would be by far the neatest and quickest means of accomplishing the task.

Next time we get together I'll tell you about what we found during our mast refit last year.

Cheers,

Jim

delmarrey · 17-12-2013, 23:50

I would NOT go with dyneema for the Forestay!

Check out my blog under "Mast Inspection and Upgrades" 2013 April.

.

robert sailor · 17-12-2013, 23:59

I'm rigging a solent stay on our boat and I'm using a T-ball fitting on the mast.

Say does any one know where you can buy a quick release deck fitting at a reasonable price??

delmarrey · 18-12-2013, 00:02

Quote:

Originally Posted by robert sailor

Say does any one know where you can buy a quick release deck fitting at a reasonable price??

They're all expensive for their size. I got lucky and got one from a CF member who removed his. The problem with these old type is that the lock ring doesn't really lock I have to tie it down so the genoa doesn't ride it up.

Stumble · 18-12-2013, 00:08

How quick do you need it to be? The ocean racer I worked on had to disconnect the forestay to jibe the spinnaker pole so we used a quick pin.

robert sailor · 18-12-2013, 00:15

I guess you could just attach the toggle with a quick pin. The only extra work would be re-tensioning the toggle each time... any other ideas out there?

robert sailor · 18-12-2013, 00:16

Some people use a couple of blocks at the deck to tension the forestay, what do you think of that??

delmarrey · 18-12-2013, 00:29

If one were to leave it setup for long periods, a turnbuckle would work good.

Weyalan · 18-12-2013, 13:54

I should mention that the plan is that the inner stay (solent stay, whatever) would spend 98% of the time strapped down at the mast. We have a furling genoa that is good, partially furled, to around 35 knots. If the breeze gets above 35 then we will fully furl the genoa and bring out the inner stay for a hank-on #4 heavy weather jib or a storm jib.

Given that the stay is going to spend most of its life against the mast, stainless steel 1x19 wire is not an option, so Dyneema was my next choice (mostly because I have lots of it). I may run a cover on it to protect it, or maybe run it bare.

The mast rigger I spoke to suggested the t-ball fitting and it is certainly the simplest solution, but I still have reservations about it, and the collar definitely has operational advantages: I envisage the collar having 2 parallel cheek-plate tangs so that I can put a sheave in between the cheek plates for the halyard (which will run down from the sheave / exit box immediately below the main forestay attachment. I can then use an extended shackle (or similar) on the outside of the cheek plates to attach the top of the stay, with a pin going through the whole lot. By comparison, the t-ball fitting will be fine for attaching the stay, but the halyard routing is more problematic.

delmarrey · 18-12-2013, 14:10

Quote:

Originally Posted by Weyalan

Given that the stay is going to spend most of its life against the mast, stainless steel 1x19 wire is not an option, so Dyneema was my next choice (mostly because I have lots of it). I may run a cover on it to protect it, or maybe run it bare.

I suppose if you have an ample supply of dyneema, then replacing it every so often is OK.

I run my inner forestay pulled over to one of the shroud chainplates and is held tout with a large bungee, which keeps it from slapping or chafing against anything else.

As well the leads for the running back stays (dyneema) are too secured at the chainplates. While the 'running B. S. purchase blocks' are stored below until needed.