The safety industry has spent considerable time convincing employers to provide safety footwear to prevent the risk of toes being lost, ear muffs to prevent hearing damage and gloves to prevent cut fingers, but height safety is another matter. Gordon Cadzow* reports.
While the safety industry has always emphasised the importance of using safety equipment to protect workers operating at height, it has also shrouded the issue in mystery and this has not helped employers understand the principles involved.
Basic rules and principles
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 the first step is to try and “engineer out” the need to work at height. For instance, the fitting of sight glasses to a storage vessel rather than climbing to dip the tank.
If this is not possible, the next step is to prevent access to the height safety risk area by the provision of lock out systems, guard rails etc.
Only when these alternatives prove impossible and access to the risk area is required should the last option of the provision of protective equipment be used. The importance of selecting the correct equipment, its regular inspection and maintenance and the training of the employees are all critical issue for separate discussion.
There are two common systems of fall protection. The first is called “restraint” where the fall protection system prevents the employee from reaching the position where a fall may be possible. The second is “fall arrest” 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 as follows:
A - Anchor point - The anchor point must be designed to stand a minimum loading of 15kN for single person fall arrest and 22kN for two people. These equate to being able to support a family car or a 4WD.
Anchor points can vary from single points to straps round suitable beams or to the 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 ANZS 1891.1 (note “designed to comply with ANZS 1891.1” is NOT acceptable).
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 date of manufacture.
C - Connector - To arrest any fall, the harness worn by the person at risk must be connected to the anchor point. There are a variety of ways in which this can be done. Rope or web lanyards are the most common but rope grabs, ladder sleeves and self retracting lifelines are all considered as connectors.
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.
D - Decelerator - 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 type 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 most commonly the fall arrest system component that is 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. This means appropriate rescue equipment and personnel must be available and rescue techniques sufficiently practiced that rescue and recovery can be effected in an acceptable time frame.
There are many other aspects of fall prevention but it is important that the basic components of the system are firstly understood.
* Gordon Cadzow is the MD of Capital Safety Group 02 9748 0335.