Snow Climbing: Roped Climbing: Snow Anchors
Anchors are needed in snow for the same reasons they are needed on rock. The equipment is different but the purposes are the same: to anchor belays and rappels and to provide intermediate points of protection.Unlike rock anchors, snow anchors are not easy to inspect nor predictable in performance. They vary widely in strength depending on snow conditions and placement, and their strength changes during the day with changes in the snow. The medium of snow is more variable than rock and requires placement of different types of anchors depending on conditions. This uncertainty makes it even more imperative than on rock to check and recheck any belay or rappel anchor. Snow anchors can also require a lot of time to put in place.
Snow anchors include deadman anchors (such as snow flukes), pickets, and bollards.
Deadman Anchor: Any object you bury in the snow as a point of attachment for the rope. Flukes are most reliable but also more difficult to place in the hard homogeneous snow of summer. They are generally used in a softer but dense pack, snow that is moist and heavy. They are least reliable under typical winter conditions, with snow layers of varying density where they may deflect off harder layers. Neither do they do well in dry, unconsolidated snow.
Picket:: A stake driven into the snow as an anchor. Pickets work well in snow too firm for flukes but too soft for ice screws. As with flukes, angle them back from the direction of pull. Attach a carabiner or runner to the picket at the snowline-not higher on the picket, or a pull may lever it out. You can drive a picket into the snow with a rock or the side of an ice ax, but a North Wall hammer or other ice hammer works best and reduces the chance of equipment damage.
Bollard: A mound of snow that serves as an anchor when rope or webbing is positioned around it. Snow bollards provide highly reliable anchors for belaying or rappelling in hard snow and are possibly the most reliable in all snow conditions. There is a significant trade-off, however. It takes a long time to build one.
Multiple Anchors: As with questionable anchors in rock, multiple anchors are safest because of the inherent weakness and unpredictability of snow anchors.
© 1997. Excerpted with permission of the publisher from Mountaineering: The Freedom of the Hills, 6th ed, edited by Don Graydon; published by The Mountaineers, Seattle, WA.
- Don Graydon
Backpack; Birds & Wildlife; DayHike; Glacier Travel; Ice Climbing; Mountain Bike; Mountaineering Basics; Winter Camping; Women;
Site designed and developed by Barbara Foley.