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The 'American Death Triangle', also known as the "American Triangle"^[1], "Death Triangle" or "Triangle Anchor"^[2] is a type of rock climbing Anchor infamous for being extremely weak when compared to other anchors by virtue of the way the forces of the load are magnified on the fixed anchors.

Contents

Description

Notes

References

See also

External Links

Description

In a 2 point climbing anchor, there are three carabiners: one at each fixed point and one at the "focal point" or where the load is going to be attached to the system. The goal is to distribute the force of the load so that each fixed point takes a portion (ideally an equal portion) of it. The anchor is formed by clipping a piece of webbing or cord through each of the carabiners in turn. The resulting triangle shape gives the anchor its name.
The force on each fixed point depends on the angle at the focal point. In the following table the percentage of the load's force that is transferred to the fixed point is listed at each focal point angle, and the same percentage is presented for the standard "V" shaped anchor.^[2]

Angle (degrees)	Percent (V)	Percent (triangle)
0	50%	70%
60	60%	100%
90	70%	130%
120	100%	190%
140	150%	290%
150	190%	380%

Aside from the magnification of forces, the death triangle violates several rules of thumb for building rock climbing anchors, such as

★ redundancy: if the webbing fails on one leg of the anchor, the entire anchor will fail.

★ extension: if one of the anchors fails, the webbing will extend and will shock load the remaining components of the system
There are situations where a climber may want to use this technique, but they are rare and require an expert to evaluate whether it is warranted. In summary, in a situation where the climber needs apposing forces to either keep passive chocks, camming devices, or spring loaded camming devices in a certain orientation (ie: a crack), they may elect to rig a triangle to create the opposing forces necessary to keep the protection in the correct orientation.^[4]
The name "American Death Triangle" was coined by traveling Canadians. The Canadian tradition of mountaineering stems from the European tradition of professional guiding (eg: the ACMG (Association of Canadian Mountain Guides) are members of the International Federation of Mountain Guides Associations (IFMGA)) whereas American mountaineering has a tradition of being self taught. When Canadian climbers who had taken courses from professional guides came across the simple, but incorrect technique they attributed it to being "American". The anchor is in no way limited to America or Americans and is merely the product of inexperience or lack or training and is used all over the world.

Notes

1. Long, 110.
2. The Mountaineers, 114.
3. The Mountaineers, 114.
4. Long, 67

References

★ How to Rock Climb: Climbing Anchors, , John, Long, Chockstone Press, Evergreen, Colorado, 1993,

★ Mountaineering: Freedom of the Hills, , The, Mountaineers, The Mountaineers, Seattle, Washington, 2002,

See also

★ Climbing

★ Mountaineering

External Links

★ Climbing Anchor

★ CLIMBING.COM - TECH TIPS contains diagram

★ Climbing Anchors includes photo