Removable inner stay.

[B27]

We need to differentiate clearly between 'stretch' and 'creep'. See Marlow tech et al....

If you're going to differentiate, 'stretch' might include both 'elasticity' and 'creep'.

The other thing people get caught out by with dyneema and other braided ropes is the 'movement' due to the strands settling initially a load is applied. Which is often significant.
It all adds up to wanting a big range of easy adjustment, like a winch with a nice big number, or a cascade of blocks, rather than something like a lever. I was sailing on a boat with dyneema (or maybe spectra?) running backstays 25 years ago, it's not new stuff, a lot of us have been there and experienced the drawbacks as well as the advantages.
My first 505 was probably built over 50 years ago (I wasn't the first owner!), that had a furling jib with no permanent stay, albeit the halyard was wire.

 

[zoidberg]

If you're going to differentiate, 'stretch' might include both 'elasticity' and 'creep'.

I s'pose you're right. However, those are the terms used by the better-known manufacturers, as explained on their websites. That's why I use them here.

The guys I've found to be extremely helpful when 'I don't know sumthink' - the 'go to' guys - are David Mossman and Paul Dyer, of Marlow Ropes. When I've sought guidance, they've always been willing to help. And I take their advices to heart.

I'm sure other makers in other lands are similarly helpful.

 

[Neeves]

I was sailing on a boat with dyneema (or maybe spectra?) running backstays 25 years ago, it's not new stuff, a lot of us have been there and experienced the drawbacks as well as the advantages.

I too bought Dyneema decades ago, to date it when Rothmans was around. I bought from Bridon, obviously before they sold the business, roughly 35 years ago (you are right - its hardly new). We used it for halyards, except spinnaker halyard, sheets, reefing lines and runner tails (basically most of the running rigging).

I had long conversations with Bridon and one thing they warned me of was the poor UV resistance of Dyneema (now found to be not correct). Rothmans wanted to keep weight down and stripped the outer cover of their dyneema running rigging - but leaving the cover intact where the cordage was subject to sunlight. And we are still seeing new applications, like dyneema chains for lifting or, closer to home, and no longer a novelty - soft shackles - which were the height of fashion only a few years ago.

Some of the draw backs originally mentioned were wrong. Some of the enduring drawbacks, like creep, have been overcome in some/many applications. A big issue was the polyester cover slipping over the dyneema core - overcome.

Interestingly, and my memory might be flawed or I was not exposed to 'state of the art' I don't recall seeing uncovered, no sheath, Dyneema. Now I see it everywhere, well almost.

Jonathan

 

[Roberto]

The bang up to date approach to this is to use a storm jib set on a furler with a dynema luff line. This is then hoisted furled and tensioned with a halyard before being unfurled to deploy.

A perfectionist might add a furling hook
https://www.karver-systems.com/en/product/kfh8-0ti-option/

 

[Porthandbuoy]

“Bang up to date” does not often appear in the same sentence as Sheolin!

The upper part of Sheolin’s temporary, or inner, forestay terminates about a foot below the genoa roller reefing stay and just aft of the furling drum at the bottom. It really needs to be capable of being tidied away otherwise there is a risk of it fouling as I wrap the genoa away. With some underdeck reinforcement I could fit another roller reefing system further aft and convert my heavy headsail and storm jib, but that is an expense I'm not prepared to take.
The hook on the spreader is a good idea, but it still leaves too much slack stay waving around.
I keep coming back to a low-creep, low-stretch or pre-stretched, hi-tech rope as a temporary stay instead of the original st/st, but thanks for all the interesting ideas.

 

[Dantp]

A big advantage to a dyneema removable forestay us the weight or rather lack of it.
I'm not talking about saving weight aloft but the momentum of the stay as you try and hold onto the end and clip it on a pitching foredeck.
We have swapped our running backs for dyneema and they are much nicer to use. I plan to swap our Solent stay from wire as well. Going to try using with standard hanks and will see how it wears. Soft hanks are an option but I think they would be too fiddly to use.

Money no object I'd be very tempted to hoist sails on a torque rope and furler.

Or stay is tensioned with a 4to1 advantage running back to a small winch. Without effort I can get it as tight as I want.

 

[gaylord694]

Obviously, you’re thinking of creep, and chafe. Neither of which apply to a removable inner stay. I wouldn’t feel ready to commit myself to dyneema permanent standing rigging for a long distance cruiser. But this seems an ideal application to me, though I’d set it up an inspect it for wear from a hanked on sail reasonably regularly. But I doubt it will suffer much. My runners are dyneema, obviously never for my forestay! But I’d consider it for my shrouds, they are not under tension when not sailing.

Obviously, you’re thinking of creep, and chafe. Neither of which apply to a removable inner stay. I wouldn’t feel ready to commit myself to dyneema permanent standing rigging for a long distance cruiser. But this seems an ideal application to me, though I’d set it up an inspect it for wear from a hanked on sail reasonably regularly. But I doubt it will suffer much. My runners are dyneema, obviously never for my forestay! But I’d consider it for my shrouds, they are not under tension when not sailing.

Think your find the COE of the mast is evenly spread through shrouds etc !... The main when on a downwind leg is always rubbing on the shrouds causing possible chafe if dyneema....... Alright for round the can fine weather sailors

 

[laika]

Our inner forestay gets tensioned with a fancy tensioner thing I picked up off eBay. Google tells me it was made by Wichard.

Isn’t that a bit like saying “I drive around in some old thing I picked up at an auction. Google tells me it’s a Bentley”?

I have one of those wichard thingies. It’s excellent. I avoid telling people how much I paid for it.