User height + lanyard length + extension (tear length) + safety margin
e.g. 2m + 2m + 1.75m + 1m = 6.75m !
Some real-life product examples:
– Petzl L59MGO Absorbica 80cm Lanyard with Scaffold Hook (1.75m after tearing) – Clearance required 4.35m (Fall Factor 2)
– Petzl L70150YM Absorbica 1.5m Lanyard with Scaffold Hook (3.6m after tearing) – Clearance required 6.1m (Fall Factor 2)
So what does this tell us? It basically reminds us to keep our anchor point as high as possible to minimise the fall distance, which in turn will reduce the amount the shock absorbing section tears and thus limit the overall fall distance. If you are using a 2m shock absorbing lanyard (the maximum length allowed), then there is a risk of hitting the ground when below 6 or so metres!
For a video explanation click here.
