July 31, 2012
Draft AS1657 – fixed platforms, walkways, stairways and ladders – design, construction and installation
The most popular safety-related Australian Standard of all time, AS1657, has been revised for the first time in 20 years and is open for public comment until September 21.
The document, which covers the selection, design, risk assessment and testing of fixed platforms, walkways, stairways and ladders has more than doubled in size from 30 pages to 75. There’s more detail and substantial new requirements. Here, member of the AS1657 committee, Carl Sachs, explains the major changes.
Selection of the means of access
Step ladder, rungs or staircase? The revised standard helps make the choices clear and assists designers to meet their responsibilities under the recently released Code of Practice for Safe Design of Structures.
Its hierarchical approach is summarized in Figure 2.1. In short, use access equipment with lesser inclines rather than steep ones wherever practicable. Use stairways at an incline of 20 to 45 degrees, for example, before using step type ladders. Similarly, use a step type ladder at 60-70 degrees in preference to a rung type ladder. Step type ladders are designed to let users’ legs do the work and on level 100mm treads, while rungs at more severe inclines may be as thin as 20mm.
So, what does “practicable” mean? Definitely not cost but it could be space constraints. A 3-metre step type ladder takes up around 1100mm on the ground when clearances are considered and a vertical rung ladder takes up around 900mm of floor space.
Other practicable considerations are the skills and capability of the people using the equipment. Much more upper body strength is required to climb a vertical rung ladder than a step ladder. Even though users may be strapping tradespeople, they often need to carry tools up ladders and these extra loads must be taken into account.
AS1657 deals with roof access, mostly for the inspection, installation and maintenance of roof-mounted plant and equipment. It specifically discusses the requirement to install guardrailing and walkways over brittle surfaces like Laserlite and asbestos cement sheeting. The standard also requires guardrailing around roof perimeters where fall hazards exist.
The requirement has been around in fall prevention legislation for many years but gains extra emphasis in this draft revision of AS1657.
The current standard mandates an interim landing platform when rung or step ladder heights exceed six metres. The platform must be a minimum length of 1.5 metres with adequate clearances around the base of the ladder to ensure that the platform is beneath the ladder and the person would access the ladder from a safe point on the platform.
The ladders are staggered with cages for extra protection. Side-mounted “midway” landing platforms are no longer acceptable. The 20-year-old standard was not clear on the purpose of these platforms and although they may have technically complied, risk assessments revealed the high risks associated with them.
The draft revision of AS1657 brings new clarity to guardrailing, which is required on platforms over 300mm. Although called up in the BCA (Building Code of Australia), it was not well understood or implemented at site or monitored.
New to AS1657 is the installation of guardrailing where there is a risk of falling off inclined walkways and rolling down, even if more than 2 metres from an edge. The committee recognized that if, for example, you step off a walkway 8 metres from the edge of a 20 degree saw tooth roof, you are likely to roll all the way to the edge and fall.
Fall protection from ladders
The standard recognizes it is not always practicable to install a 1.5m midway landing platform and stagger ladders. This is particularly common when ladders need to be installed to significant heights of, say, 6 to 30m in wind turbines, telecommunication towers and in very deep confined pits.
In these instances, ladder safety lines are a practicable solution since there simply isn’t the space to install platforms. The supervisors’ responsibility, user skills and competency and the ability to rescue the user in the event of a fall need to be considered in these circumstances.
In the telecommunications, power and mining industries, the skill level of harness users is generally higher. Rescue plans are also normally in place to rescue a fallen person quickly enough to prevent deadly suspension trauma.
In contrast, users in the facilities or maintenance environment on operational buildings (such as air-conditioning mechanics and roofing plumbers) mostly work alone and relying on self-rescue is not permitted under the newly released COP for Managing the Risk of Falls at Workplaces.
It would probably be more practicable to install landing platforms and other more permanent controls like guardrailing to control the risks – especially given the lifetime cost. Safe work at heights systems centred on harnesses demand routine inspection, a second user, rescue equipment, rescue planning and procedures, PPE like harnesses and lanyards, the cost of administration, induction and supervision, and the cost of recertification in year 10 and year 15.
Ladder cages and enclosures
Questions have been raised about the effectiveness of ladder cages but they do give the user a justified sense of containment, direct them toward the platform, can act as a rest device if you lean against it, and, when used with landing platforms, are suitable controls. On the other hand, they can interfere with a rescue when used on very high vertical ladders.
The fixing of cages to the stiles has been altered because many people climb ladders with their hands on the rungs, rather than on the stiles.
Recognizing that an open hatch is a fall hazard, the revised AS1657 prescribes perimeter protection to hatches. It also deals with the ergonomic and safety issues for access and egress.
If you can’t comply
The committee realises that workplaces may decide not to meet AS1657. If so, do a risk assessment, document the reasons for non-compliance and then record it on the equipment, which is now a new requirement of the standard.
Testing, performance based and deemed to comply
There are a number of ways to claim compliance with AS1657.
Testing equipment against the performance-based requirements.
- Engineering calculation and certification
Having a certified structural engineer run calculations and computations on the different material sections and fixings to ensure they will stand up to the load requirements.
- Deemed to comply
Some fall prevention equipment (like guardrail), has prescribed material sizes and fixings. When fixed together as prescribed, the system is deemed to comply and does not require testing or independent engineering.
AS 1657’s requirements to test guardrailing for its ability to withstand loads have changed, while new requirements have been created for stairways and ladders.
It is also very specific about reporting, spelling out the need for detailed drawings, identifying the manufacturer, the test forces applied, the test facility, approval by an individual and so on. Recognizing a widespread lack of knowledge about appropriate testing, the committee decided to increase the level of visibility and requirements for certification.
Labelling and documentation
To complement the testing, engineering and ‘deemed to comply’ provisions, the revised standard requires that equipment is clearly identified and labeled to identify conformances, or the lack thereof, on ladders, guardrailing, stairways and platforms.
The labeling identifies:
– the manufacturer or fabricator of the piece of equipment.
– the installer of the equipment.
Why does it all matter?
This is safety critical equipment and lives depend on it.
Over the last seven years, three times as many Australian people died from falls in the workplace than in the war in Afghanistan. The community cannot ignore this cost. We must be confident the lifesaving equipment on our roofs really can save lives and a relevant, manageable and well-used AS 1657 is perhaps our best bet.
The AS 1657 committee
The active members of the committee include representatives of the WorkCover authorities, electrical industry users, The Building Code of Australia, Master Builders, tradespeople, industry associations and component and material suppliers to the industry.