UKC

Was up on the Index in Cham yesterday doing some multi pitch, started running out of time so I threaded a bolt (one of those hefty circular eyelets made out of thick rod) with two ropes tied together. The bolts were at weird angles and the eyelet was so hefty that I only threaded the one bolt, but when I went to pull them they wouldn't budge. I ended up jummaring up, rerigging and the same problem happened. Long story short I missed the last lift, but I can't work out for the life of me why the ropes jammed. The ropes weren't snagged in any rock, everything looked fine when I went back up - is it possible that the weight of a 60 is too difficult to drag through a 180 degree bend with a dynamic rope? I've never ab'd off of one bolt before, so am unaware is this is a serious no-no for stuck ropes (also I'm aware having one bolt is potentially dangerous, but this thing was bloody industrial in really solid granite).

Cheers in advance

In reply to TomAlford:

Could the rope you were pulling have been trapping the loose end against the rock? Was there a lot of friction against the rock between you and the bolt?
Usually you would expect pulling through a single smooth ring to be very easy, even from 60m down

In reply to TomAlford:

Stupid question but did you try pulling both strands in case you'd got muddled?

Only time I've ever totally jammed a rope it was a pair of 60m full ropes threaded through ring bolt on a convex face, the pull side caused the ring to pinch the free strand against the rock, the friction was sufficient that that harder I pulled the harder it locked, a bit like an adjustable buckle. I guess most likely you had a few twists or the pull strand was squeezing the free strand onto/into a grippy feature in the rock.

Never had any trouble pulling 60m of rope through a krab, can't see why a staple should be any different.
jk

In reply to jkarran:
That's what I assumed as well, but gave both ropes a real hard flicking and tried to bounce them out of any jams, but when I went up to check everything was fine... like I say it happened twice, totally baffled, but I did find a burr (in my brand new dry treated halves) which suggests there may have been some stuckidge... but it's good to hear that it wasn't just lowering off of one bolt. May have been as I was pulling through a thick triple with the skinny half I'd carried in my pack for escaping. Totally mystified

Also it's worth saying, the anchor was on a reasonably wide turfy ledge, so the rope wasn't pulling straight down on the bolt, instead it was at more of an angle, and the edge was very mossy and smooth

In reply to TomAlford:

Rope cut into the turf and then knot jammed against the slot thus created??

In reply to TomAlford:

Sounds like you totally know what you're doing, but I did wonder what you meant by bouncing in one of your replies. I've sometimes had to put a prussic around the pull rope, attach it to my harness and give them multiple full bodyweight jumps to free them from the amount of friction encountered on some abseils. I can't remember the exact details as it was a while ago but they were most likely 50's or less, but can imagine this situation is only made worse by 60's, although yours do sound pretty slick.

In reply to Mark Collins:

I've found that if ropes get jammed, sometimes if you really pull on them until they're really stretched out, then let go the elasticity of the rope can cause it to bungee back which can unjam it

In reply to TomAlford:

If you're on the floor you can try walking way off to either side and pulling from a less acute angle

In reply to TomAlford:

You getting yourself in trouble in Cham Mr Alford!? I certainly won't be joining you now! :P

Josh