4
General principles for work at height
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
• Gaining an adequate apprenticeship in appropriate techniques and methods of protection is your own responsibility. Petzl solutions are
given for information only, with no guarantee of their effectiveness in your specific working situation. The relevance of these solutions varies by
context, so always do your own risk analysis in the field
• Mastering the techniques presented here requires specific training and practice; work with a specialized organization for all training activities
General information on falls
1. Restraint
The risk of falling is a key concept to master when working at height.
The severity of a fall depends on independent factors:
A restraint system limits the
work zone, keeping the
worker from entering an
area that may present a
risk of falling. This system
is not designed to arrest a
fall from height.
• The weight of the user, including his 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 in relation to the anchor:
When the worker moves above his anchor, the severity of the potential fall
increases. The fall factor concept is sometimes used to describe the position
of the worker in relation 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 for use of equipment,
particularly in terms of length of a fall and the position of the worker in
relation to the anchor.
Anticipating rapid evacuation
• Limiting the effects of inert suspension:
In case of a fall where the worker loses consciousness or is incapacitated,
inert suspension in the harness presents a mortal danger requiring urgent
treatment. 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
work site is established.
Releasable systems can be created during installation of working ropes to
allow evacuation from below.
Working alone must be prohibited: a worker may find himself alone at height,
but at least one person trained in evacuations should be present and
equipped on site.
2. Work positioning
A work positioning system
supports the user and
allows him to position
himself precisely,
supported or suspended.
This system is not
designed to arrest a fall;
the user must be under
tension on his positioning
system.
The work positioning
system must be completed
with a fall arrest system.