Founder and consultant at Over The Edge Rescue. Rescuer, instructor, guide, author, designer, and adventurer.
What’s in this post? This post is about the theory and testing behind why making a piece of webbing into a sling is 2x the strength of a single strand. We address the specific question about tension on a single section of sling around a carabiner at the end and draw vectors to show what […]
What’s in this post? Testing of a lighter weight jigger (4:1CD/5:1 pre-rigged pulley system) using a 5mm Prusik and a 6mm high strength cord made with a Dyneema core with a polyester sheath. We also address the weight and volume of a jigger to compare the lighter weight version with a standard version using a 6mm Prusik […]
What’s in this post? The basics for webbing anchors: So you know why you are using webbing anchors, what to use, set up and four ways of rigging. How to rig webbing anchors efficiently: Get the right (minimum) webbing length, rather than halfway through a rigging job finding out you are short and have to start […]
What’s in this post? Slow Pull testing the figure-8 device block variations with normal loading and incorrect loading. We also compare this to baseline methods such as the Munter mule overhand and figure-8 on a bight. Efficiency tests (speed) to find out if there is there any major differences in tying methods. Practical use comparisons […]
Canyon Rope Rescue Testing 2021 In February 2019, a team of people from the NZ Canyoning Association got together for a weekend to discuss setting up CanyonSAR for New Zealand (as a specialist discipline under New Zealand Land SAR). As part of this weekend, we discussed and practised rope rescue in the canyoning context with […]
What’s in this post? The question we are going to answer in this post is: When you drill a hole through a rock and thread a cord what is the best setup for bends, cord and rock strength. We have used an 8mm Nylon cord for cave rescue and a 6mm Dyneema cord for canyoning […]
Webbing in hangers The question we are going to answer in this post is: Is it ok to rig using webbing directly into new bolt hangers? I have rigged and used both inline and two-point anchors in a canyoning situation for years and never had any reason to be concerned. However, it was time to put […]
Back-tie rigging – tension and compression forces The other day I had a question come through about how I worked out the tension and compression forces for a post, pole or tree when you back-tie for support. The context? Before I get to the question, we need to set the context: The front anchor is […]
Introduction I was recently undertaking testing to confirm our cave rescue setup (see the post Let’s lighten the load – update). In cave rescue, as we use the double sheet bend for rigging – being easy to adjust, especially in the middle of a rope or cord – I thought it would be a good idea to […]
Let’s lighten the load – Update. After a particularly arduous 24hrs underground and 1000m of hauling on a deep cave SAREX (Search And Rescue EXercise), we started our journey towards asking the right questions about rope rescue. Could we lighten up our backcountry rope rescue gear while keeping acceptable safety margins? For lightweight rope rescue, […]
