Jackstay webbing

[Plevier]

I've just bought some ready made jackstays in polyester webbing http://www.force4.co.uk/6113/Lalizas-7m-x-25mm-Jackstay--Pair-.html (brilliant service from Force 4 BTW - ordered in afternoon and they arrived next day).
Lalizas are a reputable company and presumably meet standards but I'm surprised how thin the webbing is. Force 4 don't know its breaking strength and the Lalizas catalogue doesn't say.
It's 25mm x 1.65mm. That's the same cross sectional area as a rope of just over 7mm dia. I don't know if this is a valid comparison, but 7mm Marlow Doublebraid - scaling it from the 6 and 8 as they don't do 7 - would be about 1200kg breaking load.
That sounds enough but - it just looks a bit flimsy!
What size webbing do others use please?
(Please don't suggest wire, I have tried it and prefer webbing.)

(Interesting comparison http://www.ebay.co.uk/itm/WEBBING-B...Textiles_SM&hash=item2a0f2349eb#ht_636wt_1110 claims 20kN for 25mm x 1.6mm webbing - maybe I'mbeing too cautious.)

 

[Aeolus]

I think jackstays are usually rated at 2000kg which is pretty much the same as 20kn. You falling overboard and being dragged through the water or being swept overboard by a wave are unlikely to exert anything like 20kN/2000kg - I suspect at that force, you'd be more likely to be damaged by your harness.

 

[MM5AHO]

I've just finished making my own jackstays and harness lanyards, and thats the size webbing I used. Single thickness for jackstay, and double thickness (sewn) with snaphooks each end for harness lanyards. The double thickness wasn't to increase the strength, rather the stiffness.

 

[grumpy_o_g]

The breaking strain is not the issue here really. Imagine yourself with a small car hanging from your harness and you'll get the idea. The thing I don't trust is just as you said - the flimsiness. Aside from UV issue there's chafe and the risk of it going against a sharpish edge if you do go over the side. My thinking is that, by oversizing you're giving yourself a far larger safety margin. To put it another way a 5mm cut in 10mm webbing has done far more damage than a 5mm cut in 20mm webbing.