Rothoblaas Catalogue 2019

TECHNIQUES FOR WORK AT HEIGHT

FALL FACTORS AND ENERGY ABSORBER

Lanyards with energy absorber

Lanyards without energy absorber

F

< 6 kN

F

F

> 6 kN

F

> 6 kN

< 6 N k

max

max

max

max

H

H

H

H

L

L

L

L

L max

F

< 0,5

< 1

F

> 2

0,5 < F

< 0,5

F

C

C

C

C

FALL FACTOR

During a fall, the user must in no way suf fer an arresting force greater than 6 kN. There are two possibilities: • make sure that the cords remain constantly attached to the anchor points above the level of the head , so as the drop height and the ar resting forces generated by it can be minimised; • if the fall cannot be limited, the ar resting force must be absorbed via the most used energy absorbing PPE (energy absorbers and dynamic rope systems).

To describe the degree of danger of the fall, it is necessary to introduce the concept of "fall factor". It can be defined as follows:

F C = H / L

where:

F C

fall factor

H

height fallen during the fall

L

length of the rope / connection device

The value obtained from the equation must be between 0 and 2, with 2 representing the maximum fall factor acceptable for suspended work environments. In fact, a fall factor which exceeds 2 can give rise to de celeration that is too rapid for the human body to handle, which can cause serious injury to the worker, as well as damaging or breaking the devices in use due to the significant forces acting upon them at the time of impact.

POSITIONING AT WORK

Working technique that allows the opera tor to work under tension with its devices, hands free: • in the case where the risk of fall ing into the void is null: sling and positioning cord; • in the case where there is a risk of falling: harness, positioning rope and fall protection system.

HARNESS + positioning rope

HARNESS + positioning rope and fall protection system

14 | TECHNIQUES FOR WORK AT HEIGHT | FALL PROTECTION SYSTEMS