Skinny carabiners, carrots and bolt plates…

The good old Aussie “carrot” bolt.

When I first started climbing I thought they where called carrot bolts because they snapped so easily!

Well I’ve since trusted my life to them many times with bolt plates jangling in my chalk bag on most climbs.

Now the light weight carabiners of today with I-beam  construction don’t have the bulk to stop your bolt plate jiggling off with a bit of unlucky rope movement. Very disconcerting when you are suddenly more run-out above one.

Solutions: have a fat carabiner on hand to clip in (if you can bare carrying the extra few grams) or clip an additional carabiner into the plate.

… unless you suffer from the design disease and think there must be a better way.

I’ve just got the first prototype of my design for a locking bolt plate. Hope to run a drop test soon then some pull tests but it’s looking good so far.

Check in again to watch the development of this new design.

The video below is of a standard bolt plate showing how they can come off with lightweight carabiners. And it’s even easier to get off if orientated with the wire gate near the bolt.

Update:

I’ve had a chance to play with prototypes from the laser cutter and getting the hang of forming and assembly. Couldn’t wait for a proper drop test so rigged this on my daughters swing in the back yard: 45kg lump of wood dropped 1m onto a 1m nylon sling, video below.

Someone smarter than me estimated this drop was over 2kN. The prototype distorted but did not break which was encouraging. The peak force here was reduced by the frame flexing (would have been in trouble if I’d trashed the swing!). I’m aiming for over 20kN so this is a start.

This batch is proof-of-concept prototypes, mostly about the function of the form and assembly. They’re made in 304 stainless steel. Once I have a good understanding of the failure mode (I’m going to have fun testing these to distruction) I’ll adjust the design and make some in a higher tensile material.

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