Guard rails versus roof anchors for fall protection

Australia's roof tops bristle with horizontal life lines and roof anchors but, says fall prevention specialist Carl Sachs, most should be replaced with guard rails.

The case for guard rails over roof anchors begins with the law. WorkCover NSW’s Code of Practice for Safe Work on Roofs, Victoria’s Compliance Code for the Prevention of Fall in General Construction, South Australia’s OHS&W Regulations and Queensland’s Workplace Health & Safety Regulations each detail a rigorous selection process for fall prevention measures.

The familiar hierarchy of controls that sets out the order of control measures, running from elimination to personal protective equipment, goes further in the case of fall prevention – authorities also specify the controls.

The first step is to eliminate the hazard by reorganising the job so that work is undertaken from ground level or on a solid construction. If neither is practicable, the next best alternative is to use a passive fall protection device. In fact, the Victorian OHS (Prevention of Falls) Regulations provide an exemption from many duties if equipment complies with AS1657 – 1992 Fixed Platforms, Walkways, Stairways and Ladders.

Controls listed in both AS1657 and in Level 2 of the hierarchy of controls include guard rails and fixed platforms, which are the most viable permanent solutions for safe maintenance access of all the level 2 controls. Guard rails have a life-span of perhaps 20 years and are always in place when needed. They require a low level user skill, few administrative controls and virtually no maintenance.

It is only if these ‘passive fall protection devices’ are not practicable that ‘work positioning systems’ may be used. These systems prevent workers falling over an unprotected edge and are harnesses attached by lanyards to roof anchors or static lines, or harnesses with ropes and friction devices. If a work positioning system is not possible, fall arrest systems that also make use of anchors can minimise the distance of the fall.

Whether static lines or anchors form part of a work positioning system or a fall arrest system, their effectiveness cannot be taken for granted. They can be easily misused.

High skill levels are demanded from users and both of these anchor-based systems rely on equipment being suitable, compatible, carefully maintained and regularly tested. Users require ongoing training and administrative procedures need to be developed and constantly reviewed according to AS/NZS 1891.

The consequences of the misuse of work positioning or fall arrest systems can be catastrophic. WorkCover NSW has issued a safety guide warning of hazards associated with fall arrest latches yet fatalities continue to occur. Examples include the failure to lock due to a weakened spring, catching on clothing, corrosion or contamination and bending. Dynamic roll out, where the latch opens unexpectedly, adds to the risk.

System misuse or the incorrect placement of roof anchors can also mean level 3 fall restraint systems effectively become level 4 fall arrest systems. As a result, the site’s safety standards are lowered, generally without the knowledge of the user or facility manager. Recognising this, the 2009 edition of AS1891 stipulates planning for fall arrest even when using level 3 fall restraint systems because the likelihood of misusing a fall restraint system is so high. Removing reference to work positioning, the 2009 revision of AS1891 has dedicated an appendix to the risks associated with this technique.

Because fall arrest systems only aim to minimise injury once a fall has occurred, they also risk the potentially deadly pendulum effect and suspension trauma. Consequently, use of level 3 or fall controls – effectively those involving roof anchors or static lines – requires supervision and full emergency planning.

The cost of maintaining roof anchors and the matching fall arrest or prevention systems means that a guard rail quickly pays for itself (see Table 1). According to AS1891, roof anchor systems must be labelled with their rating and commissioning date. They must be recertified and inspected every six months in Victoria, Queensland and South Australia, and every 12 months elsewhere.

Roof anchors and static lines also make labour sourcing more complex. Using work positioning and fall arrest systems safely requires high skill levels and anyone accessing the roof, from plumbers to air conditioning mechanics, needs to have completed specialised competency-based training. Since fall arrest systems at best leave a worker hanging in the event of an accident, they must also be watched over by a trained supervisor who has a rescue plan in place.

In contrast, guard rails do not need to be regularly inspected, saving facility managers time, administration and money – not to mention avoiding any risk that the statutory inspections may have been overlooked.

Roof anchors and static lines do have their place – as one of the last resorts when guard rails are not practicable.

When the need for access to the roof is very rare, they can be an attractive option, particularly on heritage buildings where guard rails might look out of place. Solutions include powder coating the railings to match existing roof structures but, at the end of the day, aesthetic concerns mean little in the face of a prosecutor or, worse, the family of a worker.