Type of SS wire for forestay

[Drascomber]

My forestay broke recently. It is a simple set up with a thimble eye at each end secured by talurit splices and it fits inside a roller furler. The seven year old stay broke clean off immediately above the lower talurit.

The local rigger, where I found myself at the time, replaced the broken 1 x 19 wire with a new one in 7 x 7. Apparently less strong but more flexible. Assuming the break to be a fatigue failure - was that a good move?

 

[roly_voya]

Yes, if you are going to use talurit splices they should not be in 1 x 19 as it is not flexible enough to fo round the timble. As well as not being as strong it also stretches more so you will probably get more forestay sag but this is not exactly critical on a drascombe! Check it carfully each spring for brocken strands and hopefully you will get some warning when this one is going to go. If this one doesn't last look at replacing with swageless terminals, the eye type can be used just like your current talurits

 

[VicS]

[ QUOTE ]
Yes, if you are going to use talurit splices they should not be in 1 x 19 as it is not flexible enough to fo round the timble

[/ QUOTE ] Oh dear. That's condemned the rigging on thousands of small boats!
[ QUOTE ]
If this one doesn't last look at replacing with swageless terminals

[/ QUOTE ] The standard size rigging on a Drascombe may be smaller than the smallest swageless termnials. The roller furling gear may limit the posibility of increasing its diameter.

Is the 7x7 wire Ok for use with a roller, I'd be afraid of it unwinding

Just thoughts to consider!

 

[William_H]

I am not sure of the term Talurit splice I pressume it is just a copper tube which is compressed to form around the wire. A loop is formed around a thimble then 2 wires are swaged together.
The forestay would usually be made of 1X19. If the wire can't be bent around the thimble then the thimble is too small. 7X19 is what is used for flexble running rigging. (not sure about 7X7)
The failure of the old wire was probably from a kind of fatigue. It seems to manifest itself in old wire which has been subject to salt water. The lower swage seems to be the most susceptible because it collects more salt.
I used to look after a fleet of 10 dighies which got very little use considering the masts were removed between use with about 30 hours actually rigged time each year. The 1X19 wires failed (not totally but a few strands) very regularly. In fact I would suggest that there was only a safe life of 10 to15 years despite very little use. This tlliies with the general philosophy that standing rigging doesn't last longer than 10 to 15 years and should be replaced regardless of its apparent condition.

So I would suggest you replace the side stays before much longer.

good luck olewill

 

[VicS]

[ QUOTE ]
am not sure of the term Talurit splice

[/ QUOTE ] But you presume correctly!
I cant say I have heard of 7X7 wire either! I thought he might have meant 7X19 but maybe not.

 

[Drascomber]

Definately 7 x 7.

So far as I can glean from Manufacturer's web sites 7 x 19 is even less strong but even more flexible - presumably better for running rigging and 7 x 7 apparently is a common structure that fits between 1 x 19 and 7 x 19.

 

[Guest]

Roly is right about bending wire round thimbles ... but sorry to say as Vic syas - he's just condemned most boats rigging to the bin !! (Where I shall station myself strategically to catch cast-offs !!)

Bull**** to be honest - 1 x 19 is used because it has less stretch, is stiff and will take abuse of furling gear / standing gear use. Greater stranded wire is not advised because of twist.

I have just broke my Cap Shroud ... and as locally we do not have 1 x 19 (this is Ventspils Latvia - not Southampton .. Solent) - I had to go to a crane cable guy who made mine up in what appears 3 x 25 .... superbly flexible - but even he said - no problem for maybe 2 -3 yrs ... but check rig tension often and lay of cable.

Now I am not a rigger - so only go by what the riggers tell me.

Seems to me a bit like ropes ... 3 strand is better for hard wearing / rough abuse ... bit like 1x19 !!

 

[oldharry]

[ QUOTE ]
Yes, if you are going to use talurit splices they should not be in 1 x 19 as it is not flexible enough to fo round the timble. As well as not being as strong it also stretches more so you will probably get more forestay sag but this is not exactly critical on a drascombe! Check it carfully each spring for brocken strands and hopefully you will get some warning when this one is going to go. If this one doesn't last look at replacing with swageless terminals, the eye type can be used just like your current talurits

[/ QUOTE ]

I disagree. I have re-rigged a number of boats using talurits - as fitted by the original builders. Up to 4mm diameter no problem, 5mm can be difficult, but once you get to 6mm, I agree it is virtually impossible to get the wire to follow the form of the thimble. I have done it, but was not entirely happy with the results - and it was bloomin hard work!

I have just made a complete set using Talurits for a 1970 24 footer in 5mm 1x19, to replace the original Talurited rigging which had been on the boat from new - 37 years. Nothing wrong with it except that at 37 years old we reckoned it was safer to renew than go on pushing our luck! Also the insurers would have been pretty unhappy! So a properly made Talurit does not give up in a hurry!

1x19 is stronger than 7x19 by a factor of approximately 3 to 2, and does not stretch so much. I have used both and find the 7x19 marginally more 'springy'

Swageless terminals are stronger than Talurits - but also a great deal more expensive! PBO did a pull test some years ago: swaged were the strongest. swageless came next, then talurits close behind. U clamps, as found often in outboard steering systems had very little strength - but I have seen them used on small boat rigging!

The one thing stainless wire cannot stand is being regularly flexed. 1x19 will fail very quickly. 7x19 stands up to it much better, and will give advance warning of failure as individual strands part. IIRC Drascombes have a 'soft' eye at the masthead, allowing the wire to be looped round the mast to hold it. This absolutely MUST be 7x19 if stainless is used, and even it will fail relatively quickly. Far better to use galvanised wire in that application.

 

[roly_voya]

7x7 wire is the standard for 'soft' rigging such as found on gaffers and work boats and yes it falls between 1x19 & 7x19 on strength, stretch & stiffness. The important distiction is that because it is made from bundles of fine wire (ie 7 bundles of 7 wires) it is able to deform rond a bend. If you do this to 1x19, even if you can get it to lay neatly the outer wires on the bend take all the stress which vastly reduces load carrying so on a timble 7x7 will be much stronger than 1x19.

Unraveling the lay on the forstay by the roller gear should not be a problem provided it is rigged so that the sail tension is tightening the wire and you only use hands not winches to furl. It usually only occurs because the furling gear has siezed and then been forced (though I cant see why you need a furler on a headsail this size)

You can get very small swageless terminals down to 4/5mm made for gaurd wires which might do but dont know what B/S they are.

Personally on a drascombe I would use 7x7 galvanised wire spiced and served with soft eyes over the mast, works well cost nowt and lasts for ever if you gloop it anually and it looks the part to as they, are after all, a traditional ships long boat! Love them and spent many happy hours teaching kids to sail in them

 

[VicS]

[ QUOTE ]
Unraveling the lay on the forstay by the roller gear should not be a problem provided it is rigged so that the sail tension is tightening the wire and you only use hands not winches to furl.

[/ QUOTE ] That's interesting because some furl one way and some furl the other. I wonder if mine is the right or wrong . (Furls by turning counter clockwise viewed from above)

[ QUOTE ]
You can get very small swageless terminals down to 4/5mm

[/ QUOTE ] But small boats, possiblly the Drascombe, use 3mm wire. That was the reason for my comment!