Your partner breaks through into a crevasse: building an anchor, hauling with a rope clamp, and self-rescue with prusiks — explained step by step.
Your rope partner breaks through a snow bridge and vanishes into a crevasse — now what? The honest answer: you have minutes, not hours. Crossing glaciers with hidden crevasses is one of the most fascinating but also objectively most dangerous disciplines in mountaineering. Icy cold inside the crevasse, possible injuries from the fall, and the looming risk of suspension trauma (circulatory failure from hanging motionless in a harness) make time the most critical factor.
At the pro level, carrying the rope isn't enough — companion rescue is a skill that has to run on autopilot in an emergency. Just as important: you need to be able to rescue yourself after your own crevasse fall. This guide from the DOMISPORTS Academy teaches you the rope techniques, the right gear, and the preventive measures to stop a glacier catastrophe before it starts.
For a fast, successful crevasse rescue, your gear needs to hang within reach on your climbing harness. DAV safety research recommends this minimum kit for a straightforward glacier tour: - 1 ice screw: for a quick anchor point in bare ice. - 2-3 cord slings (5-6 mm): for tying prusik knots — friction hitches that grip the rope under load and slide freely when unweighted. - 1-2 sling loops (ideally 120 cm): for building an anchor or a T-slot anchor. - 1 HMS locking carabiner: for the Munter hitch belay and load transfer. - A technical rope clamp with anti-return lock (e.g., Petzl Micro Traxion): massively eases the hauling system.
The best crevasse rescue is the one that never happens. Give identified, snow-covered crevasses a wide berth in the terrain wherever possible. When that's not possible, the rope team never walks along visible or suspected crevasses — instead you cross the crevasse zone at exactly a right angle, so the whole team doesn't fall through together. If you must cross a snow bridge, put the rope under tension first and test its strength with your ice axe tip. Watch the ratio of snow thickness to the span, the snow density, and the crevasse depth.
If the bridge breaks and your partner falls, throw yourself into the firn with your ice axe immediately (self-arrest) to block the fall. Once you're stable, load transfer begins: build a secure anchor without getting pulled in by your fallen partner's weight. In hard firn, you usually dig a T-slot anchor (burying the ice axe horizontally); in bare ice, place an ice screw. Using a cord sling (prusik knot), slowly transfer the load from the taut rope off your harness and onto the anchor you've built.
Once the load hangs securely on the T-slot anchor or ice screw, untie from the rope, approach the crevasse edge belayed, and check your partner's condition. The movable pulley setup works well for the rescue itself: lower the free rope end down to your partner in the crevasse. They clip it into their harness with a carabiner. At the anchor above, build in an anti-return lock using your rope clamp (e.g., Micro Traxion). Pull the rope end, and the physical pulley effect halves your partner's felt weight. The rope clamp keeps the rope from sliding back when you re-grip or pause.
If your partner above is injured, or holding the fall but unable to build a hauling system, you need to be able to rescue yourself after your own crevasse fall. Use your cord slings: tie two prusik knots into the taut rope above you. Attach the upper prusik to a long sling loop that you step into with your foot. Clip the lower prusik with a carabiner directly into your harness's tie-in loop. Extend your leg to push yourself up, load the harness prusik, slide the foot prusik further up, and repeat (the "inchworm technique") until you reach the crevasse lip.
Judging snow bridges is extremely hard and depends heavily on time of day and sun exposure. The single most important rule: at the slightest doubt, set a precautionary anchor point (ice screw, planted axe, or T-slot anchor) and actively belay the first person of the rope team across. Many people avoid this effort — but placing an anchor costs very little time compared to a dramatic, exhausting crevasse rescue.
Always replace the classic prusik knot as your anti-return lock at the anchor with a mechanical rope clamp like the Petzl Micro Traxion. A wet, frozen prusik often grips poorly and barely slides under load. The pulley wheel in the Micro Traxion has a ball bearing that eliminates friction — cutting the force needed to haul your partner up by as much as 40 percent.
There's no exact number — but cold, fall injuries, and suspension trauma (circulatory failure from hanging motionless in a harness) make every minute count. That's why companion rescue has to run on autopilot: anchor first, then load transfer, then hauling system or self-rescue, with no time for deliberation.
A T-slot anchor is a fixed point in hard firn: you bury your ice axe horizontally, creating a stable anchor for load transfer. In bare ice, you use an ice screw instead. Both techniques safely transfer the fallen partner's weight from the rope to the ground.
It works as an anti-return lock in the hauling system: it only lets the rope move in one direction, so it doesn't slide back when you pull or re-grip. Unlike a wet, frozen prusik knot, it grips reliably even under load and cuts the force needed to haul someone up by as much as 40 percent.
Put the rope under tension beforehand and test its strength with your ice axe tip. Always cross the crevasse zone at a right angle, never parallel to it. At the slightest doubt, set a precautionary anchor (ice screw, planted axe, or T-slot anchor) and actively belay the first person across.
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