Get Outdoors - Ice Climbing: Roped Climbing: Ice Anchors

Ice climbers have several options for anchors to use in belaying or rappelling, including ice bollards, the Abalakov V-thread, and multiple ice screws. This section discusses bollards and the V-thread, which are used mainly in rappelling. The next section, on the topic of belaying on ice, explains the standard anchor set-up using two ice screws.Ice Bollards

A bollard can be among an ice climber?s most useful anchors. By linking together two bollards, one cut for an upward pull and the other for a downward pull, you have a multidirectional anchor. The strength of a bollard is proportional to its size and the hardness of the ice. Made of hard, solid ice, it can be stronger than the rope.

A completed ice bollard is teardrop-shaped when viewed from above and horn-shaped when viewed from the side. All you need for a bollard is an ice ax and good ice, uniform and without cracks or holes. Cut the outline of the bollard with the ax pick. In hard ice, give it a diameter of 12 to 18 inches across the wide end of the teardrop. Cut a trench around the bollard at least 6 inches deep, working outward from the outline with both the pick and the adze.

Undercut the sides and top half of the bollard to form a horn that prevents the rope from popping off over the top. This is the most sensitive part of the construction because you can easily fracture or break the bollard if you?re careless with the ax. The single largest disadvantage to a bollard is the long time it takes to construct one.The Abalakov V-Thread

The V-thread is a popular anchor because of its simplicity and ease of construction. Devised by Vitaly Abalakov, a premiere Soviet alpinist in the 1930s, the V-thread is nothing more than a tiny V-shaped tunnel bored into the ice, with a cord or webbing threaded through the tunnel and tied to form a sling.

Making a V-thread

Screw an 8-inch (22-centimeter) ice screw into the slope. Angle the screw uphill 10 degrees against the anticipted direction of pull; also tilt it about 60 degrees to one side.
Back this screw out about halfway, but keep it there as a guide. Insert a second screw into the slope about 6 to 8 inches from the first, angling it to intersect the first hole at its bottom. Remove both screws.
Thread a length of 7-millimeter perlon accessory cord or half-inch tubular webbing into the V-shaped tunnel. A V-thread wire?a 12-inch piece of rigid wire with a small hook on the end, available at some climbing shops?is useful for fishing out the cord from the bottom of the tunnel.
Holding both ends of the cord, saw it back and forth in the tunnel in order to break down the sharp edge where the two ice holes intersect. Otherwise, the edge might cut the cord in a fall. Tie the cord or webbing so that it forms a sling. The anchor is now complete.

The V-thread anchor has held up well in testing and in use, but remember that it can only be as strong as the ice in which it is constructed.