By Emmet McGregor*
The safety industry has always emphasised the importance of height safety equipment to protect construction workers operating at height.
However, they have also shrouded the principles of height safety in mystery.
This article is an attempt to shed some light on the basic rules and the principles that need to be implemented to increase the safety of people working at height.
Firstly, any person working at a height of greater than 2m or at risk of falling 2m or more from one level to the next must be protected. The hierarchy of control, implemented following a risk assessment, demands that the first step is to try and engineer out the need to work at height.
Only when there is no alternative should the last option of the provision of protective equipment be used.
Selecting the correct equipment, its regular inspection and maintenance and the training of the employees are all critical issues for separate discussion.
The two common systems of fall protection are fall restraint and fall arrest systems. In fall restraint systems the employee is prevented from reaching the position where a fall may be possible.
Fall arrest systems are needed where the fall protection system must assume that a fall is possible. Even when using a restraint system, all equipment should be fall arrest rated. Every fall prevention system comprises five elements:
A – Anchor Point
The anchor point must be designed to stand a minimum loading of 15kN for single-person fall arrest and 21kN for two people.
Anchor points can vary from single points to straps round suitable beams or a more sophisticated horizontal lifeline.
They can also be on davit arms or tripods for confined space and rescue work. Permanent anchor points require certification on installation and recertified annually.
B – Body Harness
The person at risk is required to wear a correctly fitted full body harness certified to AS/NZS 1891.1. It is not acceptable that the system be simply “designed to comply with AS/NZS 1891.1”.
The date of manufacture and the serial number of the harness must be clearly visible.
The full body harness is designed to spread any fall arresting forces over the load bearing parts of the body and the harness should be correctly configured for the work to be undertaken and the risks identified.
Harnesses should be inspected prior to each use and inspected by a competent person every six months.
The maximum life of a harness is 10 years from the date of manufacture.
C – Connector
To arrest any fall, the harness worn by the person at risk requires to be connected to the anchor point.
Rope or web lanyards are the most common but rope grabs, ladder sleeves and self retracting lifelines are all available.
It is also essential that the connector is compatible with the harness and anchor point at both ends and particular attention needs to be given to the elimination of any potential for “rollout” caused by incompatible hardware.
The decelerator is generally incorporated into the connector and is the device that absorbs the energy in arresting any fall.
The most common decelerator is the tear webbing, commonly called the “shock absorber”. Self retracting lifelines have clutch mechanisms that arrest the fall and reduce the forces transferred to the worker.
E- Emergency Rescue Plan
This is the fall arrest system component that is most commonly forgotten. The hazard analysis and risk assessment must include the possibility that a fall – albeit protected – may occur, and that a worker will then need to be rescued.
Rescue times must be such that the risk of suspension trauma is minimised. That means that appropriate rescue equipment and personnel must be available and rescue techniques sufficiently practiced that rescue and recovery can take place in an acceptable time frame.
There is little point in saving the person from death through a fall to lose them because they cannot be recovered before further damage is sustained.
* Emmett McGregor is marketing and technical support manager with Capital Safety Australia 1800 245 002.