Tangs for running backstay

[Guest]

I need a couple of tricky tangs for (almost) masthead split running backstays on an Elliott 7.4 on an Etchells mast section.

 

Its not going to be huge loads and I just want something clean and simple. Runners will be 5mm vectran (cased).

 

I was thinking - http://www.ronstan.com.au/marine5/product.asp?ProdNo=RF43A#related

 

Anyone think of anything similar/tidier/sleeker/stronger that this?

[MrWolf 0]

I need a couple of tricky tangs for (almost) masthead split running backstays on an Elliott 7.4 on an Etchells mast section.

 

Its not going to be huge loads and I just want something clean and simple. Runners will be 5mm vectran (cased).

 

I was thinking - http://www.ronstan.com.au/marine5/product.asp?ProdNo=RF43A#related

 

Anyone think of anything similar/tidier/sleeker/stronger that this?

 

Take a standard T-Bar hook and cut the end off it, then get a s/s loop welded to it.

You can then splice your T Bar hook to it.

 

this will then just require a hole with a T Bar backing plate rivetted to it in the mast.

 

My guess is less windage than the tangs, definitely will be a lot stronger, and t ars are good cos they self align, whereas getting those tangs to line up dead right might be harder than you realise, and if they aren't in a straight line with the load they could be quite weak.

[Guest]

Thanks Mr Wolf.

 

Like this with an eye welded on the end? Thats kinda where I was heading...

[MrWolf 0]

Yes

[Marshy 30]

S W Settle aka SwageTurn in Copsey place off Rosebank road sell them already made up with a loop. code is TRB-4 or TRB-5 or TRB-6 depending on size, T-Bar Runner loops.

 

Or Navtec do them, but they cost more.

 

All you do is fit the backing plates inside the mast.

[Guest]

Or you could use a Oliver plate (as they are sometimes known as) and splice direct to that. They are made to drop into existing T Bar backing plate slots if you change to fibre rigging from wire. Kan't unhook the stays and then stash away like T Bars though.

 

I always enjoyed fitting the T Bars, no idea why but just did.

[Guest]

Cheers Guys - sorted.

[MrWolf 0]

One more bit of info is that vectran is quite stretchy, I'm sure it will be ok, but we have been using dynex for our runners and topmasts for years.

[Guest]

I thought Vectran was really low stretch? Like <1% stretch.

 

I'll probably use 4mm Dyneema SK75 for the runners then the vectran in the cascade where its geared down a bit. Also the vectran runs really nicely through the blocks and is pretty nice to handle.

 

That means I can use up the balance of the 200m roll of vectran I have in my workshop on a 2 to 1 on the main halyard maybe even using one of those tricky Tylaska shackle thingys Mr Wolf enlightened us to a few months back.

 

After having the 2:1 on Black Fun twist up just when we needed to really, really urgently reef a few years ago I prefer vectran for 2:1 halyard setups as it doesn't get a memory like spectra i.e. no twisty things at the top.

 

Then its time to go Square Top

[Guest]

Dyneema (dynex and the rest of the names) and Vectran have the same elongation (stretch) approx. 2.8-3.3% at break. In testing we've found dyneema does tend to have a little more but that's up 'at break', which is an area you should never be playing near anyway.

 

The 3 main differences are -

- in creep, Vectran has bugger all and Dyneema some. That's why many prefer Vectran for fixed halyards like head sail and mains.

- Vectran is a little heavier

- Vectran dislikes UV more than Dyneema but again knot much in it. Best to coat both.

 

And colour if you'd like a 4th.

 

My backstay is 3mm SK75. Gotta keep that windage down

[w44vi 17]

Best to coat both

 

do you cover with it with a "plastic outer' or is there a coating ?

[Guest]

Plastic if you like, overbraid it or there are liquid coatings you can apply, which do dry obviously. It's just like paint really even if slightly differing in composition.

 

Actually there is one (maybe more) that doesn't dry but it's horrendously expensive (500 notes a lt) and slipperier than a politician in an election. Used on long hauling lines like one we did to drag a pipe through a mountain down the Naki somewhere. They want super slippery due to some much drag in the pipes. 4500kgs long one piece, quite an impressive bit of string actually or at least for the sickos that do think some ropes are sexy Found out afterwards it was used once and then dumped, the bastards.

[Guest]

Cheers Marshy - Settles is an interesting place to visit - like an untouched world of engineering - a la 1953.

 

They make some nice stuff though and sorted me out pronto.

 

Ta

 

EE

[Murky 1]

Settles is an interesting place to visit - like an untouched world of engineering - a la 1953.

You didn't try to pay by eftpos did you?

 

But like all of those great places, there seems to be virtually nothing in that line of work that is beyond their expertise - thank heaven they still exist.