Mechanical access plant
Mechanical access plant includes all mechanically operated plant that can be used to gain access for the purpose of working at height. Commonly used mechanical access plant include:
- mobile elevating work platforms
- forklift platforms
- crane lift platforms
- vehicle extension arms
- knuckle boom
These are specialised pieces of equipment often designed for particular types of operation. It is essential that the correct type of machine is selected for the intended work. The operator should be competent to operate the type of mechanical access plant.
It is essential that these types of plant are operated within the manufacturer’s guidelines.
Mobile elevating work platforms (MEWPs)
Common forms of MEWPs include cherry pickers, scissor lifts, hoists and travel towers. There are some key safety issues that should be considered before using a MEWP
Some MEWPs are designed for hard flat surfaces only (eg, concrete slab), while others are designed for operating on rough and uneven terrain.
Units powered by internal combustion engines are not suitable for use in buildings or areas with poor natural ventilation unless appropriate artificial ventilation is provided.
Mobile elevating work platforms:
- need to be clearly marked with the rated lifting capacity
- need to have a six-monthly inspection certificate displayed.
Before use the operator should ensure that:
- the MEWP has been inspected and tested within the previous six months
- the MEWP is set up level and on firm surfaces
- hazards associated with power lines are appropriately controlled
- the MEWP will not create a hazard, eg, the boom will not swing out into the path of other vehicles
- the MEWP will not be overloaded or used as a crane. (As an estimate, a person plus light tools is deemed to weigh 100 kg.)
An operator in a boom-style MEWP shall wear a safety harness with a lanyard incorporating a short energy absorber attached to a certified anchor point. The line should be just long enough to provide free movement within the confines of the bucket.
Operators should not over-reach or climb over the rails of the MEWP platform to reach a work area. The soles of both feet should be kept on the work platform.
Scissor lifts and other elevating work platforms such as cherry pickers can be used as a means of access to a work area. In this case, the worker should be protected by a double lanyard system fixed to a certified anchor point.
On a scissor lift a harness should be worn unless a hazard assessment has clearly demonstrated that the work can be undertaken without a harness and there is no risk of falling. The manufacturer’s instructions should also be followed.
A worker restrained in a boom-style elevating work platform.
Work platforms may be constructed to be raised or lowered using a forklift and these should be used in accordance with the Approved Code of Practice for Training Operators and Instructors of Powered Industrial Lift Trucks (Forklifts) – Department of Labour. Non-integrated work platforms should be designed for the specific model of forklift truck.
Forklift work platforms should:
- be made in accordance with Australian Standard AS 2359.1, Powered Industrial Trucks
- be fitted with guardrails, mid rails and kickboards
- only have any gates that open inwards and that are installed with a springloaded latch
- have a two-metre-high guard that is sufficiently wide to prevent any contact with the lifting mechanism fitted to the back of the platform
- be operated with the tilt lever on the forklift controls locked out or made inoperable; alternatively, a fall-restraint system comprising a full harness and short lanyard, allowing free movement only within the platform confines, shall be used
- have operating instructions available
- have the safe working load displayed in a prominent position
- have the platform secured to the forks in such a way that it cannot tilt, slide or be displaced
- only be used by a competent forklift operator
- only be used while an operator is at the controls of the forklift or there is an independent means of access to and egress from the platform.
Crane lift platforms
Where no other practical and suitable method is available, a working platform may be suspended from a crane and the worker must be attached to the hook. The crane operator and the person using the platform should discuss the operation and maintain direct communication by line of sight or by telecommunication at all times.
For further guidance refer to AS/NZS 2550.1 Cranes, Hoists and Winches; Approved Code of Practice for Cranes; Crane Safety Manual Crane Association of New Zealand; NZS 3404 – The Steel Structures Standard; and NZS/ASME/ANSI B56.1 Safety standard for low and high lift trucks.
A knuckle boom has a second articulated joint partway along the arm to allow for extra flexibility and reach for the work platform. The arm can be folded away when not in use, and to vary the reach in use. Knuckle booms should be used and maintained in accordance with the Approved Code of Practice for Power-Operated Elevating Work Platforms.
If an extension arm is attached to a MEWP, a design certificate from a chartered professional engineer (CPEng) with experience in this field shall be obtained. Such certificates shall show that the platform meets the criteria in AS 2359.1 Powered Industrial Trucks for a power-operated work platform in relation to stability, strength and safety, provision of operating instructions and rated capacity.
Further information on the safe use of MEWPs is provided in the AS 2550.10 Cranes, hoists and winches – Safe use – Mobile elevating work platforms.