LIMITATION OF IMPACT FORCE

Below anchoring,

the most favourable situation is the straighter below one.

Even in the case of a significant fall, for example 2 meters on a 10 meter lanyard, shock will not exceed 450 daN (for a 100 kg mass) by using a rope, being consistent with EN 1891 type A standard.
Fall factor should be taken into account, i.e. ratio between fall height and rope (or lanyard) length,
FH / rope L.
This ratio gives the shock intensity.
This ratio should not exceed "0.3" (one third) on an EN 1891 type A rope.
(Example: 1 meter for 3 meter rope, 3 meter for 10, otherwise, shock would be excessive.)
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(see shock computer)
Caution, while using a mobile fall arrester (EN 353-2), with an EN 1891 rope, one should never risk a fall exceeding one third of rope total height.
Also take care using other ropes than EN 1891 standard compliant.
Should ropes better absorb shocks (EN 892 climbing ropes, or small diameter stranded ropes), they cause fall arrester rebounds. Other ones increase the shock (i.e., polypropylene, or Kevlar ropes, or even straps or cables)
...Even with a low fall factor, significant height falls should not be allowed for all that!

Rope work hardware.

Being hanging in a harness is dangerous, See why..

Shock computer. Free of charge.

Available by e-mail.

Allows computing possible shocks while landing from a fall on :

• a static rope,
• A dynamic rope
• A lanyard
• A strap
• A cable..

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Above hooking,
an energy absorber is essential.

This is valid even if the lanyard is very short.
An absorber guarantees a shock lower than 600 daN while landing from a 100 kg weight falling.
Look out: the presence of enough clearance* should be watched in any case! *
Caution: a 1 meter fall with a 1 meter lanyard can put at risk with a shock between 900 and 2000 daN according to the lanyard quality, without any energy absorber.
Much worse, being above the anchoring, a 1 meter fall with a 0.50 meter lanyard can generate a shock between 22 kN (i.e., on a strap) and 11 kN on a stranded rope.
See shock computer.

* Clearance is the gap that should be free from any obstacle below the anchoring point.
According to the lanyards (as well as absorbers) it can vary from 3.5 m up to 6 m.

Lesion occurrence threshold while falling being in a harness is approximately 600 daN.