Protection using chocks

Chocks of all kinds are essentially very simple machines. That means that the force which the chock exerts on the rock is greater than the original force acting on the chock. In extreme cases a loaded chock can move even a several-ton rock slab. Chocks are therefore used for protection in compact and hard rock. Protection using chocks is a true art, but the one who masters it has one worry less when climbing. Of course, having the right shape of rock relief has a great influence on the success of placing chocks. The more rugged the rock, full of various cracks, seams, creases, and hollows, the easier it is to place a chock. As with all forms of protection placed in rock it is essential to realise that the strength of a placed chock depends also on the hardness of the mineral. A well placed chock in friable rock is no good. If you are climbing a route that has no fixed protection, and the entire route you are protecting yourself using chocks, it is not advisable to stint yourself. If a chock is placed in a rock crack and is in no way embedded, it is at great risk of being pulled out of the crack by the movement of the rope. Your protection will then be lost. It is also difficult to determine in advance which of the chocks used will fall out (this is based on the experience of the climber), but the more of them are placed, the greater the probability that at least some of them will hold firm. For this reason, if you have the option to place a chock, you should do so. At the same time, if you are climbing an unfamiliar route, then you won’t know which exact chocks you will need along the way (what type, shape, size, etc.). For this reason it is necessary to have a wide range of chocks in order to have a variety and to be able to select the optimal one for protection.



Placing chocks in a crack which narrows under the chock in the direction of loading.

Placing chocks in a crack which narrows under the chock in the direction of loading.

The principle of placing them in the rock is simple. It consists of finding a crack in the rock which is wider in one section and narrower in another section than the body of the chock, whereas the crack must grow narrower in the direction of potential loading due to a fall. The more points or the wider the area of the rock which the body of the chock will come in contact with in the crack, the more stable its placement in that spot will be. The suitability of the shape of the body of the chock with regard to the crack will also increase the strength of placement.

Video: A rock crack must narrow in the direction of presumed loading to such an extent that the head of the chock will not be able to pass through it.

More in e-book.

Title Part 3Mountaineering Methodology – Part 3 – Belaying and Rappelling

ISBN 978-80-87715-09-3

MMPublishing, 2013

Available for download from Apple iTunes (in the Books section).

For example U.S. store – link

Another countries – look on the page Download

See layout.

Another possibility is Google Play. This version is a simplified (as PDF).

Title Part 3 GPMountaineering Methodology – Part 3 – Belaying and Rappelling

ISBN 978-80-87715-14-7

MMPublishing, 2014

Available for download from Google Play.