When using a fall arrest system, it is critical to ensure there is enough ground clearance — also known as fall clearance — to prevent the user from hitting the ground or any obstacles if a fall occurs.

Ground clearance refers to the minimum amount of unobstructed space required below the user to allow the fall arrest system to activate and decelerate the fall safely. If there is not enough clearance, the system may not stop the fall in time, increasing the risk of serious injury or fatality.

The required ground clearance is calculated by adding together several key factors, which vary depending on the type of fall arrest system in use. These typically include:

The length of the lanyard or device

The maximum deployment/stretch of the energy absorber

The height of the user’s dorsal D-ring (harness attachment point)

A safety margin (usually specified in system guidelines)

Example Calculation:
To calculate the minimum clearance needed when using a 2m fall arrest lanyard in a fall factor 2 situation, you must combine the following:

Lanyard length (2m)

Energy absorber extension (typically 1.75m, check manufacturer’s guidance)

Height from the D-ring to the feet (average 2m)

Safety margin (commonly 1m)

Total Clearance Required: Approximately 6.75 metres
(2m + 1.75m + 2m + 1m = 6.75m)

This ensures that the system has enough room to safely arrest the fall without the user making contact with the ground or other hazards.

Key points:

Ground clearance is the minimum space needed below a worker using fall arrest equipment.

It ensures the fall can be safely stopped before the user hits the ground or obstacles.

Clearance is calculated based on lanyard length, energy absorber extension, D-ring height, and a safety margin.

Insufficient clearance can result in injury or death.

Always consult equipment guidelines and conduct proper calculations before use.

If you need further support, please contact our Technical Support Team using the email: technical@jspsafety.com or contact us via our WhatsApp.