In climbing, vector force refers to the way forces act on your anchor system in both magnitude and direction. Unlike a simple weight, which is just a downward pull, a vector splits into components along the directions of the ropes or anchors. The total force on each anchor depends on the angle between them, not just the climber’s weight.
Imagine a tightrope walker standing dead-center on the wire. He weighs 200 pounds, but the anchors at each end aren’t just seeing 200 split in half. Because of the angle in the system, each anchor can end up holding around 1,000 pounds. That dramatic increase comes from one simple rule: as the angle between two anchor points opens toward 180 degrees, the force on each anchor skyrockets.
For climbing anchors, this matters a lot. Once the angle between two points hits 120 degrees, each anchor is taking the full load. Keep angles tighter—under 60 degrees if possible—so the load shares nicely at about 50/50. A general sanity check: if your attachment system stays under 90 degrees, you’re usually in safe, sensible territory.
And steer clear of the infamous American Death Triangle. Even at 90 degrees, it amps each anchor to about 1.3 times the load. Push that triangle to 120 degrees and you’re practically doubling the force. In other words: just because the sling can make a triangle doesn’t mean it should.