Overhand Knot (on the bight) in Cows Tails.

topcat

Active member
Just one proper fall so far.......when rigging, foot slipped, all good. Saved an 18m free fall.
(Petzl Jane for me, no knots at all. And yes, I know all about the increased shock load)
 

paul

Moderator
The caver beneath me on a pitch was passing a tied off rope by a ledge part way down the pitch. They moved their Stop to the second rope continuing to the bottom (the first rope wasn't long enough). Did the usual and tried out the Stop to check it was threaded properly before unclipping their long cowstail, but were holding onto a loose tail of the first rope rather than the one they were on. After pressing in the handle of the Stop they fell the full length of their long cowstail with a bang and a bit of a shock but no other issues.
 

caving_fox

Active member
Not above FF1.... but a particularly faffy trip with a bag in Ireby. Everything was just not quite going smoothly. One of the pitch heads I was manoeuvring the bag around prior to descending and managed to squeeze it against the stop handle (ie not holding braking end due to bag). Landed at the end of my long CT wondering how I'd got there. Yes I should have locked the Stop off until I was ready to descend. Pitch was probably long enough I'd have worked out and managed to release it in time before hitting the floor.... but you don't get that long. Have seen people hit the end of CT having wrongly threaded Stop.

I've also slipped on a traverse in Juniper and been very glad CT caught me. Would have been ok, probably.
 

JasonC

Well-known member
Thanks all for your salutary tales. Good to know that falls onto CTs are fairly rare events.
 

mikem

Well-known member
Rope access way of tying cowstail with 4m length which gives you 3 points of contact (they use one for attaching handjammer), from 3 to 8 minutes:

Apparently testing showed the central overhands to be only minimally weaker than fig8 knots, but as noted above they are harder to untie. Alternatively you can use it to create 3 different lengths & not have it permanently on your handjammer.

I wonder if having a BIG central overhand on the bight would provide better shock absorption than the 2 separate knots? (It would come undone more easily, so you might want to keep a krab in the short loop to ensure that can't happen)
 
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pwhole

Well-known member
That's how I've always done mine, and it works a treat - I keep the short loop to about 10cm max, which makes traverse lines very easy. Short cowstail about 25cm and long about 50cm, and the same again (and dynamic) on my hand-jammer link.
 

mikem

Well-known member
RIMG8378.JPG

Further to what I posted with video above - right is a standard rope access cowstail, left is tied with a BIG overhand knot instead. I'm wondering if left gives better shock absorption?

Personally I don't think left is any more bulky than right. Left is a stronger knot (but right is strong enough). See also my notes above on other advantages / disadvantages. I'm pretty sure that repeated drop tests will give lower (better) results for left than right, as there is more knot available to absorb the load, but I'm not sure whether it'll make any (significant) difference on the first test - probably not on shorter drops, but it may on longer - which is what you want...

Both are tied on a suitable rope length for a standard cowstail, rather than these, so longs aren't long enough, but it was just 2 bits I had the same length & the knots used up pretty much the same amount in both.
 

pwhole

Well-known member
I agree that right is more than strong enough - falling onto the central one is trivial at that length anyway, but with two knots to split the load it's even better. Good to see all of them are nice and short - I normally do three turns on the barrel knots, which uses a bit more rope but I suspect has a lot more energy absorption.
 

mikem

Well-known member
Ah, so it would also be interesting to see what difference more wraps on the barrel knot make. Again, I think it will probably show more of an improvement on a 2nd or 3rd drop than the first.
 

cap n chris

Well-known member
The photo isn't sepia. And. It's amazing there's any space left to clip other pieces of gear onto the horseshoe.
 

mikem

Well-known member
The RH rope has been used but not in this set up, however, that layout is used by numerous cavers & even more access technicians
 

JasonC

Well-known member
My set-up is lie the RH, but I like the look of the LH version. I'm probably being thick, but how is it tied?
 
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