Running Backstays-What Size?

[delmarrey]

I've been looking at some T-ball fittings so that I can install some running backstays and it seems the largest I can find are for 9/32" stay wire. Just wondering what size of wire/dynema are on your standing rig? And I'm interested in masts that are sized for 50' or more from the cabin top.

Thanks!

[daddle]

NAVTEC NT74307 is a T-Ball fitting with an eye for line. American Rigging Supply.

I have 10mm Technora covered runners and 8mm stripped Spectra checks that join 10 feet above the deck into a 12mm hi-tech covered tail. Not sure why. Santa Cruz 50, masthead is about 58 feet above the cabin top.

[delmarrey]

Yeah I've seen those.



But they seem a bit small at 9/32". I'll talk to a rigger first but I'm trying to get an idea so I don't get snowed.

[daddle]

Yes. Check with a rigger. I doubt I ever wind on more than 1000 pounds. Usually far less. But I don't have a inner forestay carrying a sail as some do.

Buy extra of those rubber plugs. They don't float

[jcapo]

Tayana 42 masthead 53' off deck. 1/4" 1x19 runners.

John

[delmarrey]

When I build stuff it's usually over kill. Maybe I'm thinking the same here.

[Dockhead]

Mine are 14mm Dyneema, 75 foot mast.

You really need UHMW rope for this not just because of the strength, but because of the stretch. You do not want running backs, just like any other element of standing rigging, to have any stretch in them.

If you use your staysail as a storm jib (which is an awfully good use for it), then all the more, your runners should be very strong and very low stretch.

[svHyLyte]

Our runners (on a First 42) are 1/4" Spectra with the covers stripped off all but the last 10' where they pass through turning blocks to our secondaries. I doubt they see more than about 2,000# although, when we're running hard, they will take greater shock loads if we come off a wave. The Spectra replaced 1/4" wire runners that were just too hard on the main and boom.

FWIW...

[Tempo Spars]

You can get T fittings up to 7/16" from GIBB.

I would use 8mm SK75 pre stretched. Better on your sails and next to no stretch.

[SkiprJohn]

I'm thinking you're thinking overkill. Please contact a rigger. I think 9/32 stainless is overkill.
kind regards,

[stillbuilding]

Originally Posted by SkiprJohn

I'm thinking you're thinking overkill. Please contact a rigger. I think 9/32 stainless is overkill.
kind regards,

You have already received advice from a well-respected rigger in this thread

[Cheechako]

Originally Posted by daddle

NAVTEC NT74307 is a T-Ball fitting with an eye for line. American Rigging Supply.

I have 10mm Technora covered runners and 8mm stripped Spectra checks that join 10 feet above the deck into a 12mm hi-tech covered tail. Not sure why. Santa Cruz 50, masthead is about 58 feet above the cabin top.

Wow... I would have thought a SC50 had a much taller stick than that. My Passport 47 was 65 from the water, probably 61 mast length...or so...

[daddle]

An SC50 is actually a rather tiny boat. That is plenty of mast for a 12 foot beam 9 ton boat. Triple spreaders, narrow shroud base. Plenty noodle-y. I've never wanted more sail area. First reef at 10 knots true since I don't always have these 16 filipinas around to sit on the rail

[delmarrey]

Originally Posted by Tempo Spars

You can get T fittings up to 7/16" from GIBB.

I would use 8mm SK75 pre stretched. Better on your sails and next to no stretch.

Thanks!

Would you happen to have a part #? I'm only finding the Gibbs up to 3/8"/10 mm with a swag end. Or the Navtec 1/2 with swag end. There is a SW? brand up to 3/8" with a threaded end.

[Jim Cate]

Originally Posted by daddle

An SC50 is actually a rather tiny boat. That is plenty of mast for a 12 foot beam 9 ton boat. Triple spreaders, narrow shroud base. Plenty noodle-y. I've never wanted more sail area. First reef at 10 knots true since I don't always have these 16 filipinas around to sit on the rail

Yeah... one thing that the "heavy is good" contingent often ignore is how little sail area it takes to move an easily driven light displacement vessel. Really makes a difference in the effort required to work the boat.

Cheers,

Jim

PS For the OP, our runners (fractional rig, swept-back spreaders) are 7 mm Dyneema 75. Probably take more load than ones used to support a staysail on a masthead rig of similar sail area. Seem to work fine.