What is the pendulum effect?

The pendulum effect is one of the major risks present in roofing, especially at corners. UNI 11158:2015 distinguishes between the pendulum effect on linear or point anchors:

• The pendulum effect on a linear anchor is the translation of the worker on a flexible linear anchor with consequent oscillation with respect to the linear anchor following a fall from a height that occurred at an offset from the centerline of the linear anchor.
• The pendulum effect on a point anchor is understood as the oscillation of the worker with respect to his anchor point following a fall from a height that occurs at an angle to the line passing through the anchor point and perpendicular to the edge of the fall.