Crossing a bergschrund on a snow slope (source Petzl)

The specifics of the area may offer several options:

• crossing and taking the risk of no protection
• crossing with partial protection when possible
• turning back or finding another way

The leader takes the most risk, as generally there is no chance of placing intermediate protection.

Belaying the leader

If the greatest risk is falling into the bergschrund, the counter-weight of the second, farther back, may be enough.
If the risk is falling down the slope, a belay point must protect the party.
The second stays back, away from the line of a fall.
The leader's rope does not go through the belay point, as it would be torn out in case of a fall.
The second effects a dynamic belay while anchored into the deadman.

Warning: the leader will fall below his belayer without a directional anchor. VERSO and REVERSO cannot be used in this case. The second can belay from his harness with a Munter hitch or using a body belay.

Belaying the second

The leader can reach an existing anchor point or create a temporary one in the slope.
The second is belayed with a Munter hitch or a REVERSO on the anchor.
Caution: belaying from the harness with a directional point on the anchor doubles the load on the deadman because of the pulley effect.

Examples of temporary anchors

Caution:
when planted vertically, the ice axe may help support one person, but is not a belay point and carries a high risk of coming out.​​

Author and source

This Petzl technical documentation is shared on https://www.camptocamp.org in partnership with the Fondation Petzl. Petzl Foundation aims to conduct educational and risk prevention actions related to the practice of vertical activities. This documentation is available under the Creative Commons CC-by-nc-nd licence.

Author: Petzl
Source: petzl.com
Version: V1
Date: 27/01/2015