Personnel puts on the safety harness then the trolley which attached to the beam is clipped to the safety harness. The operator is now safe to access the top of vehicle without the fear of falling to the ground.
Should the personnel fall off the vehicle the life line will lock prventing the opporator hitting the ground.
This system works similar to a car seat belt. The lifeline extends and retracts to allow freedom of movement, but any sudden jolts such as a fall will lock the lifeline from extending.
