Fall arresters are designed to be used wherever a user is working at a height in a location where they could potentially fall, whilst they do not stop a fall from happening they do reduce the forces applied to the body through the safety harness. They also prevent impact with the lower lever/ground providing the height of the potential fall has been assessed and the length of the fall arrest block calculated accordingly. It is of no use if the fall arrestor is longer than the height of fall potential.
How a Fall Arrester WorksSo now we know what a fall arrester is used for, how do they actually work? A fall arrester or fall arrest block attaches to a full body safety harness and to a solid anchor point and acts as your lifeline.
A fall arrester block consists of an outer casing which houses a retractable life line and brake system with top and bottom anchor points. The lifeline remains taught through the use of an internal return spring whenever the user moves (up or down). In the unlikely event of a fall the lifeline will continue to expel from the housing until a critical velocity is reached which is when the brake will kick in to decelerate the line over a short distance, quickly slowing you to a stop to prevent you hitting the ground. This deceleration much reduces the force and stress imposed on the user and therefore lowers the risk of serious injury.
Some fall arresters incorporate a rescue winch which enables the user to winch themselves back up if they do happen to fall. This type can also be used for lowering and raising the wearer in and out of tight spaces.
Checks, precautions & Care of your Fall Arrest BlockAt the end of the day, a fall arrestor could literally be a life saver and therefore one would assume that it will be treated with care, maintained accordingly and used correctly to minimise the risk of malfunctions or misuse. Before each and every use a thorough check should be made to ensure all is working as it should. You should check every strap, buckle, connector, rivet, grommet, housing, rope or webbing for any potential issue which could affect it; remember to check your safety harness too, never be complacent, your life could depend on it.
Ensure your harness is fit to use and wear it correctly ensuring it fits snugly where it should with no twisted straps. Keep all height safety equipment clean and store according to the manufacturer’s advice.
Calculating Fall Factors
It is of no use to use a fall arrester if the fall factor and fall distance has not been calculated correctly. People who work from height on a regular basis should undertake a formal training scheme to ensure they understand there equipment, what it does and why, and calculating the risks.
Fall arrestors are available in a wide range of lengths and it’s so important you get the right one for your task; use the diagram below to help calculate potential fall distances.
Remember you will need to have a rescue plan in place just in case, this is required by the HSE