The route requires an abseil down a gully. I was wearing an Alpine Bod harness which doesn't have a belay loop, so the karabiner has to go around the harness itself and also the strap connecting the leg loops. It was only when I unclipped at the bottom that I found that I had attached the abseil device to the rucksack waist belt instead of to the harness. If the buckle had failed I would have only been held by the leg-loops (which also depend on buckles) and an autobloc.
I had checked before abseiling but saw what I expected to see - a krab around a black webbing strap. A tug on the rope held, although it was only held by the side-release buckle on the rucksack. I was last to go so there was no one to buddy-check me.
My lessons from this:
Be extra vigilant when there is no one to buddy-check your setup.
I am now more aware of the possibility of clipping the waistbelt so will specifically watch for this.
I would probably use a sling around the harness to extend the belay device, as this is easier to thread around the harness than a krab (especially as I am not a slim as I used to be!)
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