Fc < 6 kN Fc > 6 kN Fc > 6 kN

c < 6 k Fc < 6 kN c > 6 k c > 6 k

GENERAL PRINCIPLES OF WORK AT HEIGHT

Clearance

disregarded

Clearance

Lanyard with

ABSORBICA-I or Y

energy absorber

JANE or PROGRESS lanyard

without energy absorber

Example for 100 kg

Suspension

Work Positioning

Fall Arrest

The user is working while suspended

when they no longer have any weight

on their feet, but are supported primarily

by the harness. The load is thus shared

between the waistbelt and the leg loops/seat.

A work-positioning system supports

the user and allows them to be precisely

positioned with the weight on their feet.

This system is not designed to arrest

a fall; the user must keep their body

weight on the positioning system.

The work-positioning system must be

used together with a fall-arrest system.

Warning

• You must have understood and retained the information from your products’ Instructions for Use to be able to apply the techniques

presented in this document.

• Learning appropriate techniques and methods of protection is your own responsibility.

Petzl solutions are given for information purposes only, with no guarantee of their effectiveness in your specific working situation.

The relevance of these solutions varies by context, so always carry out your own risk assessment in the field

• Mastering the techniques presented here requires specific training and practice. Work with a specialized organization for all of

your training activities.

The fall-arrest system is a belay system

that is independent of the means

of progression or work positioning.

The fall-arrest system prevents the user

from falling to the ground in the event

of a fall. Its role is to arrest the fall while

limiting the impact force experienced

by the user. It must therefore be used

with enough clearance to allow for

an unobstructed fall.

General Information About Falls

The risk of falling is a key concept to master when

working at height. The severity of a fall depends on

independent factors:

• The weight of the user, including equipment:

The greater the weight, the more energy

to be dissipated during the fall.

• The length of the fall:

The longer the fall, the more energy to be dissipated

during the fall. The risk of hitting an obstacle is also

greater.

• The position relative to the anchor:

When the worker moves above their anchor,

the severity of the potential fall increases.

The fall factor concept is sometimes used to

describe the worker’s position relative to the

anchor and the severity of the fall. This concept

applies to climbing, restraint, or work-positioning

situations, when a dynamic rope lanyard is used.

Precautions for the type of system used:

the Instructions for Use specify the limitations

on use of equipment, particularly in terms

of fall distance and the worker’s position

relative to the anchor.

Restraint

A restraint system

limits the work zone,

to help prevent the worker

from entering an area that

may present a fall risk.

This system is not

designed to arrest

a fall from height.

Impact Force

A fall-arrest system helps limit the impact

force sustained by the user.

It is typically made up of an energy absorber

that tears in order to limit the forces over a

given stopping distance.

A dynamic rope lanyard has a low capacity for

energy absorption. Its use requires taking great

precautions: reducing the potential fall distance

and staying in a work position below the anchor.

A webbing lanyard or a cable with no capacity for

energy absorption cannot be used to arrest a fall.

Clearance

Clearance is the minimum amount of clear space

below the user that prevents the user from hitting

an obstacle in the event of a fall.

Clearance takes into account:

- Weight of the user

- Length of the fall

- Tearing length of the energy absorber

- Average height of the user

- Safety margin of 1 meter

Clearance Value

The tearing length of the energy absorber,

depending on the fall, can only be known based on

the manufacturer’s information; this is why a clearance

estimate is suggested in the Instructions for Use for

each fall-arrest device.

Anticipating the Means of Rapid Evacuation

• Limiting the effects of inert suspension:

In the event of a fall where the worker loses consciousness or is

incapacitated, inert suspension in the harness presents a mortal

danger requiring an urgent response. Work teams must be equipped

and trained to quickly evacuate an injured team member.

• Evacuating a victim without assistance:

Procedures for evacuating workers should be determined

whenever a new worksite is established.

Releasable systems can be created when installing work ropes

to allow evacuation from below.

Working alone must be prohibited: a worker may find themselves

alone at height, but at least one person trained in evacuations

should be present and equipped on site.

I n f o r m a t i o n i s n o n-e x h a u s t i v e. R e f e r t o t h e o t h e r p a g e s a s w e l l a s t h e I n s t r u c t i o n s f o r U s e a n d t e c h n i c a l m a n u a l s. T e c h n i c a l t r a i n i n g i s e s s e n t i a l.

To learn more about calculating clearance, see

the technical information available at Petzl.com