Fall arrest

There are many different combinations of products that are commonly used to assemble a personal fall arrest system, and each must meet strict standards.

Typically a fall protection, sometimes called fall arrest class is 8 hours long for general workers, but may include a second 8 hours of training for workers who climb communication towers, or oil derricks.

Archived 2015-02-11 at the Wayback Machine [4] To arrest a fall in a controlled manner, it is essential that there is sufficient energy absorption capacity in the system.

Without this designed energy absorption, the fall can only be arrested by applying large forces to the worker and to the anchorage, which can result in either or both being severely affected.

The standard mitigates PPE interchangeability problems, allows wide use by designers not versed in high rate energy methods, and it limits the force into the worker to a survivable level.

The most common fall arrest system is the vertical lifeline: a stranded rope that is connected to an anchor above, and to which the user's PPE is attached either directly or through a "shock absorbing" (energy absorbing) lanyard.

It is normally essential to include energy (or shock) absorbers within HLL in addition to those within the workers' PPE.

Without such absorbers, the horizontal life line cannot deform significantly when arresting the fall.

Because of the geometry of pulling across the horizontal line, this in turn results in large resolved forces being generated within the anchor system, sufficient to cause failure of the anchorage.