DIY Jackstays - D ring strength

[stranded]

I am making up new jackstays from 25mm webbing, which I understand has a break load of around 3 tons. I am planning on stitching with V92 dabond with a long overlap and copying the thread pattern from the Jimmy Green old ones. I would like to include d rings in the loops as I wasn’t happy with the way the dyneema lashing scrunched the webbing at the loop, but the strongest 25mm rings I have found are 5mm wire with a break load of 800kg. This looks like a relative weak point (albeit to this non-engineer still quite a strong one), yet I have read a number of people advocating d rings - do they know something I am missing?

 

[Plum]

I am making up new jackstays from 25mm webbing, which I understand has a break load of around 3 tons. I am planning on stitching with V92 dabond with a long overlap and copying the thread pattern from the Jimmy Green old ones. I would like to include d rings in the loops as I wasn’t happy with the way the dyneema lashing scrunched the webbing at the loop, but the strongest 25mm rings I have found are 5mm wire with a break load of 800kg. This looks like a relative weak point (albeit to this non-engineer still quite a strong one), yet I have read a number of people advocating d rings - do they know something I am missing?

How about using these? Ikar IKV01 Screwed Triangular Connector

Www.solocoastalsailing.co.uk

 

[wrr]

D rings are dependent on the weId which lies hidden in the loop. I would not be happy to rely on this, so I use Wichard self-locking large 6mm shackles for this purpose. These accommodate 25mm webbing without distortion. The stated breaking load is 1500 kg and the only component in the loop is the shackle pin.

 

[Neeves]

We made our jackstays the same way.

We use standard Crosby 2t rated galvanised bow shackles with the 3/8th" pin through the sewn loop.

Check the safety factors being used when WLL limits are being quoted - they vary, a lot.

The jackstays are only installed when we go offshore (as we would not leave them 'unused' in the sun).

Not quite as pretty as a stainless shackles - but not the weak link (which is the jackstay).

No point in having good jackstays if you do not pay the same attention to the tethers, hooks and strong points. Thinwater did a lot of work on tether hooks - send him a PM.

Jonathan

 

[Stemar]

My jackstays have eyes sewn into them and shackles to attach them to U bolts in the deck. I wouldn't trust rings, D or otherwise, though I rather think that applying a load, even a brief shock load, of 800Kg to me, even through a harness would make the eyes water a bit.

 

[Poignard]

I use extra wide shackles bought from Jimmy Green which have a 25mm jaw opening.

 

[dansaskip]

Instead of webbing why not use Dyneema? I swopped to using 6mm Dyneema for my jackstays and it has lots of benefits, stronger, not affected by UV and less affected by abrasion and a safety tether slides along easier. In addition really simple to put eye splices in the ends using a Brummel splice and then you can use a ss shackle.
Nowadays there is quite a bit of stuff on internet about using dyneema for lifelines.

 

[Neeves]

Instead of webbing why not use Dyneema? I swopped to using 6mm Dyneema for my jackstays and it has lots of benefits, stronger, not affected by UV and less affected by abrasion and a safety tether slides along easier. In addition really simple to put eye splices in the ends using a Brummel splice and then you can use a ss shackle.
Nowadays there is quite a bit of stuff on internet about using dyneema for lifelines.

Just a note of caution. Lifelines and jackstays are 2 different applications. We replaced our stainless lifeline with dyneema - and have not regretted it. I've never used a jackstay in anger, I have used them but never fallen. I'd want to read about dyneema being used in jackstays before committing. We use tethers with some elasticity - which is why I query. Being thrown over the side at 10 knots mike be near the point where my eyes might water and I bite my tongue - with dyneema - I don't know.

Where is thin water when you need him?

Jonathan

 

[Stemar]

I had wire jackstays on Jissel when I got her. After a couple of attempts to throw me overboard by rolling underfoot, they got sacked. Would there be a similar issue with Dyneema?

 

[Neeves]

You can source Dyneema tape.

Jonathan

 

[dansaskip]

I had wire jackstays on Jissel when I got her. After a couple of attempts to throw me overboard by rolling underfoot, they got sacked. Would there be a similar issue with Dyneema?

I have not found that to be an issue. I used to have wire jackstays yes they were horrible - moved to webbing and now dyneema.

Just a note of caution. Lifelines and jackstays are 2 different applications. We replaced our stainless lifeline with dyneema - and have not regretted it. I've never used a jackstay in anger, I have used them but never fallen. I'd want to read about dyneema being used in jackstays before committing. We use tethers with some elasticity - which is why I query. Being thrown over the side at 10 knots mike be near the point where my eyes might water and I bite my tongue - with dyneema - I don't know.

Where is thin water when you need him?

Jonathan

Yes I appreciate that lifelines and jackstay are two different beasts, but I used the term lifelines because an internet search using that term reveals more results in sizing and splicing. Anyway we are talking of replacing webbing jackstays which have no stretch or elasticity with dyneema, so I can't see the objection on that score.

 

[Neeves]

I'm lost - the OP mentions webbing, without defining what textile he is actually going to use - but a 3t UTS does not sound like dyneema (and will therefore have some elasticity). Dyneema comes in as many forms as any other textile, you can have hollow tape, solid tape or various forms of cordage (braids, double braids, dyneema core, polyester cover etc etc. - I had assumed, possibly incorrectly, that the OP was talking of using sold tape (and I did not consider he was talking about Dyneema (as the UTS is too low?)

The OP is going to sew his webbing, is tape and webbing the same thing?, so no splicing.

I think I missed something - I'm showing my age

Jonathan

 

[stranded]

Interesting replies guys, thank you - tend to confirm my wariness about d rings. I had favoured them over shackles because a shackle is quite a lump of unpleasantness underfoot, but maybe I need to accept that trade off to get the strength. I also considered dyneema, but put off by reports of rolliness underfoot - mostly it will sit in the angle between side deck and coach roof but be on open deck for a bit on fore and afterdeck. Anyway, I already have the webbing (“high tenacity 25mm polyester”) so that is the start point this time round. I’ll look at shackles - though the 6mm self locking Wichards that wrr refers to seem only to have 12mm internal pin length - I’d need the 12mm wire size to get 27mm of exposed pin - that’s one solid little nugget of pain!

 

[Poignard]

Interesting replies guys, thank you - tend to confirm my wariness about d rings. I had favoured them over shackles because a shackle is quite a lump of unpleasantness underfoot, but maybe I need to accept that trade off to get the strength. I also considered dyneema, but put off by reports of rolliness underfoot - mostly it will sit in the angle between side deck and coach roof but be on open deck for a bit on fore and afterdeck. Anyway, I already have the webbing (“high tenacity 25mm polyester”) so that is the start point this time round. I’ll look at shackles - though the 6mm self locking Wichards that wrr refers to seem only to have 12mm internal pin length - I’d need the 12mm wire size to get 27mm of exposed pin - that’s one solid little nugget of pain!

Petersen 8mm Extra Wide Jackstay Dee Shackle

 

[wrr]

Interesting replies guys, thank you - tend to confirm my wariness about d rings. I had favoured them over shackles because a shackle is quite a lump of unpleasantness underfoot, but maybe I need to accept that trade off to get the strength. I also considered dyneema, but put off by reports of rolliness underfoot - mostly it will sit in the angle between side deck and coach roof but be on open deck for a bit on fore and afterdeck. Anyway, I already have the webbing (“high tenacity 25mm polyester”) so that is the start point this time round. I’ll look at shackles - though the 6mm self locking Wichards that wrr refers to seem only to have 12mm internal pin length - I’d need the 12mm wire size to get 27mm of exposed pin - that’s one solid little nugget of pain!

These have 25.5mm clearance on the pin: Self-locking large shackle - Dia 6 mm | Wichard Marine

 

[stranded]

These have 25.5mm clearance on the pin: Self-locking large shackle - Dia 6 mm | Wichard Marine

Ah - my apologies sir - I should have read your post more carefully - thank you very much for the link - I think that will be the answer then.

 

[rogerthebodger]

I had my jack stays made from 50mm wide seatbelt webbing folded in half and sewn to make double 25 mm.

I then had one of double safety latch attached to each end with a sown loop.

Mine have a 25 mm slot for the webbing.

A friend has some D rings in the loops of a canvas cover and the welded joint wore through the webbing. I have a number that I purchased to that job but never used then for that reason

 

[penberth3]

How about using these? Ikar IKV01 Screwed Triangular Connector

Www.solocoastalsailing.co.uk

Looks good, as long as they're stamped with the rating and not something cheap and nasty from a hardware shop.

Another option is the plain and simple climbing carabiner, also tested and marked, £5 to £10 each.

 

[Gary Fox]

I use lashings, and just accept the compression of the sewn-in loop in the tape. Does it weaken the webbing? I believe not, or not significantly.
Actually, on reflection, lashings spread the chafe over a greater area of the tape loop, compared to a shackle pin which concentrates the load.
Using lashings means you can take up any stretch during the season.
But it's different for each boat, depending whether you are bending onto a little stainless deck eye, or a 5" square sampson post
edit, I'm impressed by 'stranded's needlework skills!

 

[stranded]

edit, I'm impressed by 'stranded's needlework skills!

Now you’ve really worried me - doesn’t look that hard!