How To Correctly Calculate Fall Clearance

Length of Lanyard and Harness:
A 6’ lanyard may seem sufficient while working at a height of 10’ or 12’, but it’s easy to forget  about the deceleration device. When a deceleration device is deployed, it adds an additional 3.5’  to the length of your lanyard. Also, a harness could stretch so that the D-Ring, while initially positioned properly between the shoulder blades, ends up a foot or more above the worker’s head after a fall.

Length of the User’s Body:
It is necessary to take into account the length of the user’s body below the D-ring. On average, it is usually safe to consider approximately 6’ feet for this distance.

Length of Anchorage Point Connector – Including Sag:
A fixed, solid anchor point is easy to calculate because the only distance to add is the length of your snap hook. However, when dealing with an anchor like a horizontal lifeline, things get more complicated. Additional training is needed for use on these systems as the manufacturer has specific instructions on the use of these.

Safety Factor:
The conventional wisdom on this safety factor is an additional 3’, which brings our total length of PFAS including body length to 18.5’ (without sag). Now think back to your projects, your facility,
or work you’ve observed. How many times did you see a 6’ lanyard with a deceleration device used with a clearance of less than 18.5’?

What can you do?

• Consider using a retractable or shorter lanyard.
• Raise your anchorage point.
• Ask a competent person ie. Safety Dept.