Fall Arrest or Fall Restraint

Fall Arrest or Fall Restraint

17th February 2015

We all know that working at height can be a risky business and that we need to use the correct equipment to minimise the risks involved and protect ourselves from accidents.  Today, we’re taking a look at fall arrest and fall restraint – two terms that may appear to mean the same thing as they are both methods of fall protection.  To clarify matters a fall arrest is something that occurs after a person has begun to fall – it’s a system that stops the person mid-fall in order to prevent an impact at a lower level.  A fall restraint, on the other hand, is a restraint system that stops a person from falling in the first place.

A fall restraint system is usually provided by a fixed length lanyard and a body harness or body belt.  The lanyard acts as a leash and prevents a worker from reaching the leading edge where they may fall.

A fall arrest system is required if a worker is able to reach the leading edge and it can be breached by their centre of gravity.  If a fall occurs from an elevated point a worker’s potential energy converts into kinetic energy and the worker will impact a lower level unless he is decelerated in some way.  The absorption of this kinetic energy is the biggest challenge faced when designing and implementing an effective fall arrest system. 

The basic requirement is to design and engineer a system that will prevent a worker’s body from absorbing all of the kinetic energy (as would happen on impact to a lower level) and ensure that the fall arrest system absorbs the kinetic energy instead.  The type of energy absorbers used in fall arrest systems include shock packs, rip stitch lanyards or disc brake mechanisms.  Whichever method is used the energy absorber will decelerate the falling worker to zero mph and prevent any injury that would have occurred had he reached a lower level or an obstacle.

Here at Safety Fabrications, we also think that there is a need to clarify the technical differences between fall arrest and fall restraint. 

A FALL RESTRAINT SYSTEM can be used when the working environment has a working surface from zero degrees up to 18. 4 degrees of slope.  The 18.4 degree slope is used because this represents a common 3.12 pitch on a roof.

A FALL ARREST SYSTEM is required in a working environment with slope angles greater than 18.4 degrees because that means a worker can no longer be restrained from an edge.  In this type of scenario, the slope itself becomes the fall hazard. 

Understanding the working environment and the nature of the fall hazards that may be faced is of vital importance when choosing the type of fall protection system that should be used.