Falling on an ascender and rope failure

[softbankhawks]

3 ropes connected to an anchor ring. The dark blue is the anchoring leg - colour coded velocity : blue for work & orange for rescue.

I like this because a twin line footlock can be turned into a single line work position system without lanyard-ing in.

If they were static kernmantles you could run a cammed system with seperate back-up.....maybe.....? I haven't tried that yet.

[Mr. Squirrel]

you could just run a dynamic cowstail to tether yourself to the hand ascender. If the cam goes on the croll, there should be stretch in the cowtail to lessen the load onto the hand ascender.. OR just get your act together and setup your access line and climb so you can't shockload the ascenders.

 

Technically you really should be using a dynamic attachment to your hand ascender anyway. Basic caving SRT setup. Good point though.

 

Or back up your ascenders with a hitch above or a mechanical device like a dmm buddy or isc rocker

 

I vaguely remember an article in the ISA magazine where they looked at backing up ascenders with a hitch. Now I may be wrong, but I'm pretty sure their findings were that since it's being advanced by your ascenders the knot is generally very loose and is unlikely to arrest a fall should the ascender fail.

Though it wasn't the focus of their investigation, since the knots weren't doing much and all the shock was put on the ascenders they ended up snapping a number of ropes.

 

I'll have to dig it out, as their findings were somewhat relevant to this.

 

It's be interesting to see the breaking strain on those ropes post ascender mauling softbankhawks. Obviously the advantage of the kernmantle is that it's just the sheath that's ripped, the core is still largely intact and the rope retains most of its strength. Not so with a 16 strand.

[MOG]

whats the need for Dynamic rope to hand ascender? when you are attached straight to binner and croll etc? surely if you have broken the croll/ripped the rope/ and so on, half a metre of dynamic rope not going to do much?

 

on kernmantle the sheath rips... which means you fly down on the sheath with a strong core? dont really see the bonus in that?

 

unless like you said had a hitch above and maybe that grab the core. but like others had said if you have any of thoses problems you are in serious ..... way better to do good assessments and rethrow if unsure.

 

MOG

[Mr. Squirrel]

whats the need for Dynamic rope to hand ascender? when you are attached straight to binner and croll etc? surely if you have broken the croll/ripped the rope/ and so on, half a metre of dynamic rope not going to do much?

 

on kernmantle the sheath rips... which means you fly down on the sheath with a strong core? dont really see the bonus in that?

 

unless like you said had a hitch above and maybe that grab the core. but like others had said if you have any of thoses problems you are in serious ..... way better to do good assessments and rethrow if unsure.

 

MOG

 

Your hand ascender is there as a backup too, should your croll etc. fail. That could be just a twig poking the lever open, stuck in the cam etc. your foot slips out loop and you're shock loading your back up. Your right it isn't much really, but the dynamic rope's elongation + tightening of knots under shock load will absorb some of the fall. It's like you say, if you actually do get in these situations you are really scraping the barrel for some good luck, in which case it might not be a bad idea.

 

That was more of a personal thought, I figure if I was 20m off the ground and I shock loaded my access line I'd rather end up hanging from a relatively intact, very strong core than a climbing line with a shredded sheath. As I said, it'd be interesting to know what the comparative strengths post test were to clarify that.

[Marc]

Some intresting stuff, Paul love your ring idea with both work and rescue line. Something that is very popular amongst us is always having a rescue access line this is one of the benefits of SRT wether you use it only for access or for both access and work position.

 

Sorry I am a bit slow to reply sometimes I do not come on for weeks and have several thousands post to look through.

The situation I mentioned earlier where the climber used a toothed ascendor to pre tension his work line was like this.

Tied in to a main central stem, swung across and up a large sub leader and redirected through a natural fork, he found the give between the 2 stems created to much sit back when he weighted his line, he came up with a novel idea, he lanyarded in installed a cambium saver passed a bight of line through the ring to a hand ascendor placed between the cambium saver and his tie in point creating mechanical advantage... How this helped I'm not sure.

[BenR]

Tie a clove hitch around the redirect with a bight of rope, backed off with two half hitches and a biner. It can be tensioned slightly to support the redirect and reduce slack. Much better than using an ascender in a life support situation on double braid lines and less gear intensive

 

Marc, I mentioned the situation you explained to Drew Bristow when he asked if there was anything I suggested needed to talking about at a 2 day srt summit in the states he is at. This meeting is apparently with everyone from up top in the industry, ISA, TCIA, treemagineers, itcc, arb assoc etc.

 

My response was two topics. Separate specific SRT training for access techniques and work positioning techniques, aimed at arbs. The second stopping, the use of toothed ascenders on double braid and 16 strand ropes in life support situations in case people get themselves into shockload situations in ascent. Obviously that should never happen anyway, but not everyone is that switched on and mistakes happen sometimes.