American death triangle

Content sourced from Wikipedia, licensed under CC BY-SA 3.0.

The American Death Triangle is a risky rock and ice climbing anchor pattern. It can magnify the load on fixed anchors and often isn’t redundant.

In a normal two-point anchor you use three carabiners: one at each fixed point and one at the point where the rope load is transferred. A triangle anchor clips a length of webbing or cord through all three carabiners, creating a triangle. The force on each fixed point depends on the angle at the triangle’s point. Sharper angles can push more load onto the anchors. In some cases the total load on the anchors is greater than the rope tension.

Besides higher forces, the triangle pattern usually lacks redundancy and good load distribution, making it less reliable. There is a variation where a loop is clipped to both anchors and the third carabiner goes over the loop; if an anchor fails, the loop can slip.

Two safer options are:
- Put a half twist in the cord and clip the free carabiner through it. If an anchor fails, the free carabiner stays attached to the cord, but if the cord fails the whole anchor can still fail.
- Tie off both strands of the cord with a knot (e.g., an overhand) so the lengths to each anchor are fixed, adding redundancy but sacrificing perfect equalization.

In rare cases, an experienced climber might use a triangle to manage opposing forces in cracks, but extra redundancy and measures to prevent extension are essential.