Tree Work
Redirect Force Calculator
A redirect (changing rope direction without adding MA) puts load on the anchor that depends on the angle change. A 90° redirect adds 1.41× the load to the anchor. Enter your load and the redirect angle to see the result.
Force on redirect anchor (lb)
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- Anchor multiplier
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- Force vector sum
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- Angle change
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FAQ
What angle adds the most load? +
A 180° redirect (rope doubles back on itself) puts 2× the rope tension on the anchor. A 90° redirect adds 1.41×. A small 30° redirect only adds ~0.52×.
Does a redirect give me mechanical advantage? +
No. A pure redirect changes direction only — pull force in equals pull force out (minus pulley friction). Add a movable block to get actual MA.
Common mistake? +
Treating a sharp redirect like a friction-free pivot. Rope-on-bark or rope-on-carabiner adds significant friction and shock-load risk. Use a proper pulley or low-friction ring for any redirect.