Dyneema shock/safety cords

[Mark Wright]

I think the thread title has probably confused people.

I doubt the OP envisaged the use of the term 'shock cord' to mean an 'elastic cord' as GT is suggesting.

Mark 

 

[FionaH]

I can't speak for OP but I can tell you they are away on expedition at present so it might be more than a week before you get a response, GT.

 

[Chocolate fireguard]

I used prusik knots over 20 years ago on the Humber Bridge. We had them wrapped around the metal handrails to stop a potentially very high FF5 fall factor. They were replaced regularly. 

Mark

Nobody likes to show ignorance and I've been waiting weeks for somebody else to ask, but they all obviously understand.
How do you get a FF5?
The only way I can think of is to have part of the arresting rope replaced by steel cable, which can't be right.

 

[pwhole]

I'm guessing that if connected to a diagonal cable without the choke of a prussick and a fall were to occur, you'd slide all the way down the cable to the next junction and then your lanyard-arrest distance would kick in, so there's essentially two 'separate' fall factors to be added together?

 

[Chocolate fireguard]

I think I see.
So the cable and handrail were parallel and without the prusik on the handrail it would have been possible to slide down the cable for a (vertical) distance equal to 4 times the lanyard length?

 

[Mark Wright]

I think I see.
So the cable and handrail were parallel and without the prusik on the handrail it would have been possible to slide down the cable for a (vertical) distance equal to 4 times the lanyard length?

That's exactly it.

Via Ferrata lanyards are designed for such FF's.

Mark

 

[GT]

We'll be doing some drop tests on that soon as well!!

 

[rhyst]

In the original question I was referring to this sort of dyneema cord: https://starlessriver.com/shop/ropes_and_cords/pure_dyneema_5mm_per_metre

Sent from my Redmi Note 4 using Tapatalk

 

[GT]

Cheers Rhys, so thats not really shock cord at all

Will drop some when the weather improves!!

 

[GT]

Finally got around to writing up the results on some various options for lanyards between hand jammers and harness. The link is below but the rub of it is don't fall onto your jammers!

Dynema and sling type lanyards don't stretch so yield high impacts. 5mm accessory cord snapped (as did the dynema bungee cord)...

http://www.train4underground.co.uk/2018/12/30/drop-tests-on-srt-foot-loop-lanyard/

 

[IanWalker]

very interesting, thank you for doing that.