The original mission was to construct a shock-absorber ( screamer) out of components found on an average rack. Furthermore, the rig had to be "reusable". This has an advantage over mission-specific, shop bought shock-absorbers, which are "use once". Although some manufacturers offer a "return for a re-stitch" service, this is not really viable mid-route or if you are based in the middle of nowhere.
Following on from a suggestion on ukclimbing.com from Sandy Wilson, I spent £1.49 for a packet of rubber bands from Partners, to build myself a stretchy quickdraw.
ComponentsYou will need:
Note: Click on the pictures for an enlargement ( 1-2mb) |
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Construction1. Make the quickdraw using about 30 rubber bands. As the rubber band "dog-bone" ( the tape bit of a quickdraw) will be quite thick, ensure that the karabiner gates are facing opposite each other. This will load the rubber band "dog-bone" onto the back bars of both karabiners. |
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2. Wrap some electrical tape round rubber bands to neaten things up and give the rubber bands some protection. |
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3. Add the essential back up sling.
Note 1: All rigs must be backed up by a sling. |
The Theory1. The stretchy quickdraw is used to connect suspect protection to the rope. In the event of a fall, the quickdraw will dissipate additional energy by stretching. This should ( in theory) reduce the impact force on the suspect protection, making it less likely to fail. The additional 60cm sling provides a backup in the event of the rubber band "dog-bone" failing. |
Testing2. Warning: Do not use this rig! These pages are provided for information only. I have NOT tested this rig in any way whatsoever. |
Update and Test Results3. 02 September 2007: I can proudly report that after some testing, I have used and fell on Mr. Fantastic in the field. I was climbing on Earl Crag 2 weeks ago, attempting a wet, green poorly protected slab route. We had already done 3 routes in the wet and it seemed like a good idea at the time! Mr. Fantastic ( backed up by a short 60cm sling) was clipped into a poor WC-00 cam placement about 12 feet up. I attempted the crux rock-over, reaching for a very small and wet crimp. Nope! Wasn't going to happen! I tried to reverse the move but fell about 3 feet above the cam. It's strange how you notice the little details but I saw Mr. Fantastic stretch then the cam popped. By this time, I was only 2 feet or so above the wet ground. The only thing hurt was my ego and there's a bum shaped imprint in the ground to mark the start of the route. Mr. Fantastic survived intact! |
4. Things to note:
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As with any Chris Tan Death Product, usual disclaimers apply. Use at your own risk! < Usual laugh follows>
Note: Usual copyright & disclaimers apply. If you would like to use the information or any of the pictures contained in these pages, contact Chris Tan by first removing the Walnut.