Mechanical advantage systems can involve large forces and break things that cause catastrophic failures that can cause harm to people. In particular, raft d-rings can break which can result in harm to people pulling on the rope.

Things we can do to reduce the chance of injury:

1. Use a 2 or 3 point anchor on the raft
2. Use a redirect
3. Add a damper (mass) to the rope
4. Follow the Rule of 12 (below)

Rule of 12

When pulling on a rope in a whitewater environment we try and follow the "rule of 12" which means that we try not to exceed 12 when we multiply the number of people pulling by the theoretical mechanical advantage we're using.