When working at height, it is mandatory to be equipped with suitable rescue devices and to train the work crews so that they can quickly rescue any worker who may remain hanging in his harness after a fall.
The efficiency of operations by the work crews is essential for quick and effective rescue of the injured party. Often the organized rescue intervention time by a third party (i.e. fire brigade) may be too long and therefore cause worse consequences for the injured party.
It is just as important to provide systems designed for self evacuation of the work crews in the event of grave and imminent dangers (i.e. fires, strong winds, storms).