LINQ Minimum Free Space

The LINQ by ProChoice Safety Harness Fall Arrest System is designed to minimise the impact of a fall. When used and fitted correctly, your LINQ height safety equipment will minimise the danger associated with working at heights.

Be mindful of the area beneath your immediate work space and seek out a safety zone. The safety zones are also referred to as Minimum Free Space (MFS), a straight vertical line between the point of anchorage and the ground; the nearest dangerous obstacle or platform.

The Fall Arrest Harness System will not prevent impact with obstacles or obstructions in the path of a fall. It is imperative that you ensure the MFS below the work area is sufficient enough to allow the Fall Arrest System to halt contact with the obstacle(s).

MFS criteria and risks reduce significantly if product warning labels are heeded – All ASNZS 1891.1 products are marked FALL NOT TO EXCEED 2M.

It is the duty of the user to be familiar with the MFS available and apply the following formula:



To illustrate a worst-case scenario, which is when the anchor point is at the worker’s feet, (to be avoided at all times) the MFS is calculated as follows:

Lanyard length + Shock absorber element = 2m + 1.75m (maximum extension of the shock absorber element in an extreme fall) + Harness system stretch 0.40m + Distance from anchor point (at feet) to harness attachment point say 1.8m (for a person of 2m height): Add 0.5m provisional distance if wearer weight is < 136KG.

2m + 1.75m + 0.4m + 1.8m = 5.75m  (A wearer >136kg should take extra care in the calculation of their MFS – extra reading AS/NZS1891.4)

Refer to the diagram below. Correct calculations are important.