The most important thing to realise about snow anchors is
that their strength will depend on the consistency of the snow and the surface
area of the object buried; in powder snow nothing will hold. Some of the below
anchors are too time-consuming to be used as runners during a climb and are
likely only to be used for creating a belay.
Radically curved ice axes can compromise the holding power
in uncertain snow conditions. Dig a clean slot using the adze in undisturbed
snow perpendicular to the direction of loading; the front, load wall, of the
slot should incline slightly to help stop the axe lifting. Cut a narrow slot
using the spike, just big enough for a sling to fit into. It is important it is
the same depth as the ice axe slot, to prevent the axe being lifted out. Attach
a sling with a clove hitch or girth hitch at a point on the axe that ensures
the surface area is the same on both sides of the sling. Do not use the balance
point as it invariably pulls through at the head end. Firmly place the axe,
pick downwards, into the snow. Driving another axe or ski pole, just back from
vertical, through the sling in front of the horizontal axe will reinforce the
These can be placed upright in very firm snow or buried like
an axe when the snow is not so firm. If you can push it in by hand it is
unlikely to be secure. A T-shaped profile is the strongest and may have better
holding power in softer snow than a buried axe belay. On steep slopes they
should be placed at approximately 45 degrees from the direction of pull; on gentler
slopes the angle can be less.
This is a specially shaped, aluminium plate
with a metal cable attached. It is useful as a belay anchor and as a runner.
They are most useful in slush or moist and heavy snow,. It is best placed at
about 40 degrees from the direction of pull with a deep slot to allow the cable
to run directly to the belayer. but great care must be taken to ensure that you
dig deep enough and that there are no hard layers to deflect the deadman.
These are strong and reliable in good snow, but are
time-consuming to build (fig20). The bollard should be horseshoe-shaped, not
tear-dropped, to keep as much snow in the anchor. The trench should be at least
30 cm deep and the diameter of the mound at least one metre in good snow and
even 3 m in poor snow. The bollard can be padded with cardboard, clothing or
ice axes to stop the rope cutting through the snow. If it is used as an abseil
anchor, the ice axes and padding can be removed when the last person abseils.