Ice climbing

Ice climbing is the activity of ascending inclined ice formations. Usually, ice climbing refers to roped and protected climbing of features such as icefalls, frozen waterfalls, and cliffs and rock slabs covered with ice refrozen from flows of water. For the purposes of climbing, ice can be broadly divided into two spheres, alpine ice and water ice. Alpine ice is found in a mountain environment, usually requires an approach to reach, and is often climbed in an attempt to summit a mountain. Water ice is usually found on a cliff or other outcropping beneath water flows. Alpine ice is frozen precipitation whereas water ice is a frozen liquid flow of water. Most alpine ice is generally one component of a longer route and often less technical, having more in common with standard glacier travel, while water ice is selected largely for its technical challenge. Technical grade is, however, independent of ice type and both types of ice vary greatly in consistency according to weather conditions. Ice can be soft, hard, brittle or tough. Mixed climbing is ascent involving both ice climbing and rock climbing.

Techniques
A climber chooses equipment according to the slope and texture of the ice. For example, on flat ice, almost any good hiking or mountaineering boot will usually suffice, but for serious ice climbing double plastic mountaineering boots or their stiff leather equivalent are usually used, which must be crampon compatible and stiff enough to support the climber and maintain ankle support. On short, low angled slopes, one can use an ice axe to chop steps. For longer and steeper slopes or glacier travel, crampons are mandatory for a safe climb. Vertical ice climbing is done with crampons and ice axes (those specific to vertical ice generally being called technical ice axes, or ice tools); climbers kick their legs to engage the front points of the crampons in the ice, and then swing the axe into the ice above their heads. This technique is known as front pointing. The strength of the ice is often surprising; even if the axe goes in only a centimeter or so it is enough to pull up on. If a climber is leading, they will need to place ice screws as protection on the way up (see climbing system). Most mountaineers would only consider the last scenario true ice climbing; the less steep variations are routine aspects of winter mountaineering.

Some important techniques and practices common in rock climbing that are employed in ice climbing include knowledge of rope systems, tying in, belaying, leading, abseiling, and lowering. Beginners should learn these techniques before attempting to ice climb. It is highly recommended that one acquire knowledge from experts and experienced ice climbers.

Rope systems
Single, double, and twin rope are the three main rope systems used in ice climbing. The single rope system, which is suited for straight climbing routes, is the most commonly used rock climbing system in the world. Also often used in climbing is the double rope system which is a more flexible system than the single rope system. Lastly, the twin rope system, which uses two twin ropes in a single rope system, is used for longer multi-pitch routes. Double and twin rope technique is used more frequently in ice climbing because these systems are more redundant, an important consideration given the number of sharp edges the ice climber carries with him. Impact force on ice is an issue, with double ropes gaining popularity over twins.

Tying in
Tying in entails attaching your rope to the climbing harness. This technique is a must particularly when leading a climb or belaying. A commonly used tie-in knot is the Figure-of-eight follow through, but the Bowline and Thumb (stopper) knot is often preferred, since it is easier to untie when frozen. This technique should be done properly to ensure your safety when ice climbing.