top of page



Date of Incident






Southern Sandstone 29 May 2020 - ground fall from incorrect anchor set up.

Failure to set up top rope anchor correctly on SS route. My climbing partner was adjusting a sling's length in a daisy chain of slings by knotting it with a doubled overhand/figure of eight so the end carabiner was just over the edge of the crag with the top rope hanging from that.

He had been recently told by another friend that a way to make the knot easier to undo after loading was clipping another carabiner through the knot. When you want to undo the knot, you can remove the carabiner producing some slack in the knot. Having no spare carabiners he re-clipped the carabiner being used as part of the anchor through the knot, re-clipping only a single stand of the doubled knot. (I have emailed pictures)

This caused the sling to be no longer firmly attached to the carabiner and when the anchor was subsequently loaded from a climber falling the knot unravelled and the carabiner came free, resulting in a ground fall for the climber.

I, nor the other members of the party, did not check the anchor system after it was incorrectly set up as we had confidence in the experience of the user in question. The person setting up the anchor had been climbing sport/UK trad for 3+ years and was considered experienced.

Luckily he was only approx 8-10feet up and landed on sand/grass rather than rock/logs and suffered no major injuries, although probably has a sore back today. The climber ended up falling on his back with the top rope, carabiner and the un-knotted sling. The rest of the anchor system was still in place.


This was a clear case of user error but the user in question had ~3 years experience of sport climbing. The advice of use another carabiner to clip into the knot is probably reasonably well known and do try and avoid tight knots, e.g. when abseiling. When the carabiner was re-clipped in, superficially the knot may have looked correct and substantial.

Analysis afterwards showed that if he had clipped the other strand, or the centre of the knot, i.e. both strands, if the knot unravelled the carabiner would still be in the loop of the sling and the system would not have catastrophically failed.

I guess the advice is: Don't experiment with single points of failure without properly exploring what could happen in a safe environment.


Trad rock climbing




Minor injury


Anchor Error



Reported By


Wearing Helmets?


Rescue Services Involved?

No rescue services used, climber felt fine

Please find attached a photo of how the sling came out from the carabiner.



31 May 2020 at 15:37:29

For more advice and guidance on good practices visit BMC skills

All reports are self-submitted and have not been edited by the BMC in any way, so please keep an open mind regarding the lessons and causes of each incident or near-miss. 

bottom of page