Abalakov thread

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Abalakov thread (V-thread, A-thread, or 0-thread)

The Abalakov thread is a simple ice-anchoring method used in ice climbing. It creates a secure point to hang or lower a rope without using bolts. The technique is named after Soviet climber Vitaly Abalakov.

What it is
- A V-shaped anchor inside solid ice made from two holes drilled from the surface that meet at the ends.
- A cord or webbing is threaded through the holes and tied off with a knot (fisherman’s knot or water knot) to form a loop.
- The abseil rope is attached to this loop.

How to build it (short version)
- Drill two holes in the ice at about 45–50 degrees to the ice surface.
- Space the holes about 17–20 cm apart and make sure the holes connect at the ends to form the V-channel.
- Thread cord or webbing through the holes and tie a secure knot to create a loop.
- Use the loop to hang or lower your rope.

Key notes
- The Abalakov thread works best in solid ice (or good rock). If the ice is weak, you can balance the load with two Abalakovs, but consider another route if a second anchor is needed.
- A-thread refers to a vertical arrangement (one hole above the other); a thread that is horizontal with holes side-by-side is called a V-thread. A 0-thread uses rope through the holes directly, leaving no trace but the rope can freeze.
- A 2009 study found vertical (A-thread) arrangements to be about 12% stronger than horizontal (V-thread).
- Many climbers use a backup ice screw for the first abseil to improve safety and to assess the anchor’s strength.

See also
- Abseiling
- Ice climbing
- List of Russian inventions