# Grant Prattley

Founder and consultant at Over The Edge Rescue. Rescuer, instructor, guide, author, designer, and adventurer.

### Floating anchors: But what if the anchor blows?

Introduction Floating anchor: but what if the anchor blows? Isn’t it going to rip the other anchor out? I hear this as a common statement quoted back to me when talking about a two-point floating anchor (aka self-equalising, magic X, etc.). I can only think it’s based on the assumption you have: Built or chosen […]

### Which bends for joining ropes? – Update

Introduction As part of writing the Canyoning Technical Manual, I needed to find out more about flat bends. For my own peace of mind, I had to make sure what I was putting in the book was suitable. We undertook some testing in 2015 including a control test and five flat (offset) bend variations.  In 2020, […]

### How much friction for your device?

How much friction for your device? We were interested to know (as a guide) how much a lowering device can hold for rescue in particular but also personal use. The testing is for practical use when out on a rescue, training or instructing a group about how much it can hold in relation to: the […]

### Life on the edge: testing the edge kit

Introduction We have used an edge kit for several years. Over this time, I have never done any testing on the combination of Purcell Prusik (Prusik on a Prusik), Prusik hitch 6mm on 8mm cord and double overhand (scaffold) hitch onto a carabiner. There has also been an assumption made that the edge kit would […]

### Time to meat human anchors

Time to meat Human Anchors A temporary human (meat) anchor is used in sports such as caving and canyoning, to get the first or all but the last person down, using a person (or people) that is suitably positioned in a stance where they can use the friction of rope on the rock, their own […]

### Forces on an inclined plane and Tippy the tip truck

Forces on an inclined plane and Tippy the tip truck How do you figure out the forces is a common question I get when teaching a particular subject. None more so than those on an inclined plane (or slope). Rather than getting onto the whiteboard to explain, from time to time, I bring out Tippy the […]

### Pulley system progression

Pulley system progression – is it worth it in practice? A pulley system progression is when you go from a small to a large mechanical advantage (MA). For example, from a 3:1s (s means simple) to 3:1sCD (CD means Change of Direction) to a 5:1s, to a 9:1c (c means compound). Note: You need some prior […]

### Vlad to help – a master carabiner

Vlad to help – a replacement for the master carabiner Back in November 2018, I decided to purchase a Grivel Vlad and put it on my harness to see if it was going to be a useful addition. The Vlad could be helpful as a master carabiner for anchor station organisation for multiple clip-ins. There are […]

### The Perfect Storm

The perfect storm – keep an eye on your rigging We were on a canyoning trip recently when we were using a figure-8 abseil device as a block. Over the last eight years, I have probably rigged it over 500 times and never had an issue. However, on this occasion, all the holes in the Swiss […]

### Jigger Setup: Troubleshooting

Jigger Setup: Troubleshooting As we head around various rescue groups, we find many jiggers (aka a set of fours) rigged incorrectly or operating inefficiently. Despite leaving everything in good working order, we often come back at a later time and see the jigger fairies have come in and made a mess. To illustrate my point, […]