Worksite Safety Update Promoting safety in roadwork No 129 January - March 2014 In this Edition: Managing the Hazard of Mobile Plant Operations near People Human Factors Considerations.. Page 1 Preventing Plant Overturns...Page 4 Managing Safety on Piling Work & Foundation Engineering Sites.Page 6 Managing the Hazard of Mobile Plant Operations near People Human Factors Considerations Incidents involving Mobile Plant reversing / tracking into people during road construction and other works continue, despite attempts to control this hazard around Australia and the world. The management of this hazard is improving on longer term road projects in Victoria with higher level controls becoming more evident. Investigations conducted into mobile plant incidents involving pedestrians (workers or public) frequently show that the safety controls are more likely to depend on administrative type controls. The practicability of higher level controls for short term works is the reason given for applying the lower level controls. Administrative controls are known to be less reliable and based on incident experience obviously the least effective under the hierarchy of safety controls applicable to mobile plant operation. They may be also described as the least safe control. Why are Administrative Controls less reliable for Mobile Plant Operation? Human Factors Considerations for Pedestrians (Workers or Public) Sensory Warnings Administrative controls involve prescribed behavior and require pedestrians to rely significantly on their hearing and vision to warn them of danger from mobile plant movement. Warning systems mandated for mobile plant traditionally have consisted of a yellow flashing light (visual warning) and an operating reversing / tracking alarm (audible warning). This is appropriate but these warning devices are known to have limitations because we depend significantly on our hearing and visual senses to warn us of approaching mobile plant (including vehicles) which may present a collision risk. Hearing Limitations The mechanical sounds of the plant movement may provide some additional audible warning (noise from excavator tracks for example) but rubber tyred vehicles / plant are usually more silent and the general noise from multiple plant operation can mask the approach of a single item of plant presenting an imminent risk of impact. This is why operating reversing or tracking alarms are mandated for mobile plant. If a pedestrian worker is wearing standard hearing protection this may also compromise their ability to detect an approaching item of plant. It has also been reported that workers tend to switch-off to multiple alarms if they do not consider they are subject to an immediate risk, and tend to concentrate on their work. Page 1 of 7
Visual Limitations Pedestrians depend on their vision to look out for approaching mobile plant. Some of the lower level administrative controls typically require that a minimum clearance be kept from plant, typically 3 to 5 metres. This depends on our ability to look out for mobile plant while we are working when our visual focus is primarily centered on the work task and which does not involve the item of plant involved. Mobile plant can quickly close and compromise / encroach clearances particularly if the operator cannot see a person because they are in the plants blind spot. General Situational Awareness Our situational awareness requires visual contact to confirm approaching mobile plant and its location and this is usually combined with our hearing to detect the noise produced by the plant. If the plant is quiet or multiple plant operations are conducted in the vicinity this noise may mask approaching plant and when combined with our vision being directed to the work task and away from mobile plant our alerting senses can be significantly less effective. Cognitive Distraction More complex work tasks requiring significant concentration result in cognitive distraction increasing the likelihood of missing or ignoring sensory warnings of plant approach. Mobile phone use is a good example of an activity which can result in a cognitive distraction with safety implications while driving or walking near traffic which has been subject to many studies, but can have a similar safety reduction outcome. Human Factors Considerations for Mobile Plant Operators Sensory Warnings The operator of mobile plant primarily depends on their visual sense to detect and avoid pedestrians, other mobile plant and objects in the workplace. The noise from their plant reduces hearing effectiveness from external communications unless radio is used. Blind Spot Visual Limitations Forward movement of plant often has some operator visual blind spots but this is generally much less than when reversing when the blind spots tend to be significantly larger and extend a greater distance from the plant. Operation of the plant into the blind spots is generally the greater risk because people and objects such as slip base light poles which could be knocked over and fall onto people or traffic are hidden from the plant operators view. Mirrors may reduce the blind spots but do not eliminate them, cameras are also becoming more prevalent but may also have blind spots and they need to be checked before and during plant movement. Tracked plant, such as excavators, frequently has large visual blind spots behind the operator s cabin and on the boom side of their machine (see typical blind spot diagram on next page). Operating Plant into Blind Spots Any plant movement into these blind spots means that the operator cannot see who or what may be in the area. Consequently if they move their plant into a blind spot they are taking a significant risk of driving their plant into objects or anyone who is in the hit zone or has moved undetected into this area. Mobile plant can quickly close and compromise / encroach clearances particularly if the operator cannot see a person because they are in the plants blind spot. Page 2 of 7
An example of the significant Blind Spots shown in grey above for a typical excavator. Mirrors are not used on this machine they can reduce but not eliminate blind spots. Discussion / Summary Sensory warnings may be compromised for plant operators and / or pedestrians when they are not effectively separated with mobile plant operations as described above. This may be a significant contributing factor when mobile plant is driven into a pedestrian and increases the risk of serious or fatal injuries where administrative controls are used to control the risk. The OHS Regulations Section 5.1.2 considers any movement of powered mobile plant within a construction worksite to be high risk work. Under Section 5.1.7 there is an obligation to control the risks via what is often called the hierarchy of controls commencing with the safest most effective and reliable controls that (1) eliminate the hazard or if this is not reasonably practicable (2) reduce the risk if this is reasonably practicable and (3) apply administrative / behavioral controls the least safe option. There is also an obligation under Section 5.1.7 that: (1) An employer must eliminate any risk to health or safety associated with construction work, so far as is reasonably practicable. (2) If it is not reasonably practicable to eliminate a risk to health or safety associated with construction work, the employer must reduce that risk so far as is reasonably practicable by (a) substituting, for the hazard giving rise to the risk to health or safety, a new activity, procedure, plant, process or substance that gives rise to a lesser risk to health or safety; or (b) Isolating persons from the hazard; or (c) Using engineering controls; or (d) Combining any of the risk control measures in paragraphs (a), (b) and (c). Page 3 of 7
(3) If an employer has complied with sub regulations (1) and (2) as far as is reasonably practicable and a risk to health or safety associated with the construction work remains, the employer must, so far as is reasonably practicable, use administrative controls to reduce that risk. Reasonably Practicable is defined by WorkSafe Victoria in their publication: the WorkSafe position to How WorkSafe applies the law in relation to Reasonably Practicable November 2007: Eliminate the Use of Behavioural / Administrative Controls Many of the top tier contractors now require that the controls shown in green above are used in preference to the least safe administrative controls. When you consider the limitations of administrative controls the importance of separating plant and people so far as reasonably practicable becomes an imperative. This should be the objective, so far as reasonably practicable, if the loss of life and serious injuries from mobile plant incidents is to be effectively prevented. Where Higher Level Controls May Not be Reasonably Practicable However, the industry recognises that it is not always reasonably practicable to use higher level controls particularly with short term works so are seeking to enhance the behavioural level controls or including a combination of controls to reduce the human factors limitations described above. Plant Awareness Training Top tier contractors now provide training for personnel on site in respect to General Plant Safety Awareness, including the limitations of view available to the plant operator and the danger in placing oneself in the blind spots at any time. Typically these blind spots are behind the plant but in the case of slewing plant it can be beside the plant as well (see diagram on previous page). It is also a requirement under the OHS Regulations, Regulation 2.1.2 to provide information, instruction and training into site hazards and the risks. Apparent Risk Taking behaviour such as workers walking behind or even standing behind with their back to the plant may reflect a lack of understanding of the mobile plant and vehicle blind spot hazard. Spotters Spotters are often assigned to work with plant and it is important that they receive training in plant movement directing signals and radio / communication procedures. They also need training as to where to stand so they are fully visible at all times to the plant operator and located in a position of safety. High visibility clothing with something to indicate their training as a Spotter also helps to identify their role and authorisation to be near plant in a position of safety. However, Spotter also applies to overhead power line safety which is confusing. Public The public need to be kept out of plant operating areas ideally with a perimeter security fence or safety barriers to prevent unexpected short cuts through the worksite. On longer term worksites this is more practicable and the area can also become a designated Pedestrian No Go Zone for unauthorised workers. This article has been provided as a contribution to improving pedestrian safety management where mobile plant operations are involved. If higher level controls are not considered practicable and administrative / behavioural controls are selected then the human factors limitations need to be taken into account and a combination of controls implemented. This combination should include plant awareness training, removal of blind spots and movement of plant and vehicles into blind spots. Page 4 of 7
Preventing Plant Overturns WorkSafe Victoria recently issued a Safety Alert with respect to Mobile Plant Overturns. Although this Alert was primarily intended for mines or quarries the risks and recommended control measures are also applicable to roadwork, including construction and maintenance operations. VicRoads have issued many safety alerts /safety bulletins and related articles in this newsletter with respect to this risk, including the need for operators to wear their seat belts to reduce injuries in case they overturn. The reason why plant and vehicles overturn should be well known yet they continue to occur. Some plant operators may not be aware of the risks. Construction or maintenance practices do not always plan the works to reduce the risks. Operator error is also a contributing factor. Operator competency based training may not always include the overturning risks for the type of plant. This article has been produced so that this area can be better managed by those who have control of the worksite to eliminate these incidents. No serious injuries have occurred to date where seat belts have been worn on road construction works. However, mobile plant operations are high risk construction work and the overturning hazard (as well as other mobile plant related hazards) must be identified in the Safe Work Method Statement (SWMS) and suitable controls identified, clearly described and communicated to those concerned. WorkSafe Safety Alert Background In a recent incident, a fully loaded articulated dump truck overturned while travelling along a section of sealed road inside a mine. The truck was turning into an intersection when the rear of the truck (the tub) overturned, leaving the truck s prime mover upright. Since January 2010, thirty reported mobile plant overturn incidents have occurred in the Victorian earth resources industry. Of these, fourteen related to dump trucks, with the remainder comprising light vehicles (four), loaders (four), excavators (three), scrapers (two), water trucks (two) and one dozer. Nine incidents involved articulated trucks. Mobile plant overturns commonly involve the following factors: Unstable ground conditions soft ground that is unable to support the vehicle s bearing load can cause it to overbalance. This could occur along the edge of a road or when a vehicle is dumping overburden material at a tip head. Uneven ground different surface levels can raise the body of a vehicle causing an overbalance. Uneven ground may be common around tip heads. Uneven roads vehicles can lose control while travelling on roads that are uneven or incorrectly cambered around bends. Loss of vehicle traction on the road surface. Vehicle failure caused by defective, worn out or poorly maintained vehicle components including brakes, steering, tyres or suspension. Collision with other vehicles or objects. Other factors can include: The type of load some materials (e.g. soft, sticky clays) may remain in the vehicle body, potentially causing an overbalance while dumping. Uneven vehicle load distribution. Poor road signage, traffic management and communication practices. Recommended risk control measures: Ensure appropriate safe systems of work are in place and these are regularly monitored, reviewed and, if necessary, revised. Page 5 of 7
When reviewing systems of work, consider any changes in a vehicle s design limits (e.g. speed, load or gradient limits) or technological developments and the availability of the latest operator protective devices (such as reversing cameras etc). Provide employees with training on new or revised systems of work (e.g. drivers unfamiliar with the make or model of the vehicle they are expected to operate should receive appropriate training). Ensure onsite roads are safe and properly maintained taking into account changing environments and conditions. Establish appropriate rules and standards for safe onsite road use, including speed limits for travel and man oeuvres, taking into account changing environments and conditions. Before new or hired plant is used in the workplace, ensure any necessary information is obtained from the supplier or manufacturer about its features and design limits. Communicate any necessary information to drivers and others (e.g. load information for those responsible for loading and driving vehicles) to enable them to perform their work in a way that is safe and without risks to health. Ensure the surface of any off-loading area is appropriate for the vehicle s requirements/manufacturer s recommendations. Ensure mobile plant is operated in accordance with manufacturer s recommendations (including load limits and other specific features). Ensure regular vehicle inspections and maintenance are undertaken on essential components such as brakes, steering, tyres (including pressure) and suspension in accordance with the manufacturer s recommendations, or where practicable, by the manufacturer s authorized service provider to enable a safety standard comparison. If a mobile plant overturn incident occurs: Ensure an investigation is conducted into the cause of the incident by a suitably qualified and competent person having regard to the relevant manufacturer s specifications. The outcome of the investigation should be documented and retained. Notify WorkSafe Victoria immediately if the incident occurred at a mine. Disclaimer: This Alert contains information following the Victorian WorkCover Authority s (VWA s) inquiries into the incident at the date of this report. The information contained in this report does not necessarily reflect the final outcome of the Victorian WorkCover Authority s action with respect to this incident. The VWA does not warrant the information in this report is complete or up-to-date, and does not accept any liability to any person for the information in this report, or its use. A copy of the WorkSafe Alert may be obtained from: http://www.worksafe.vic.gov.au/ data/print_to_pdf.php?url=https://www.worksafe.vic.gov.au/forms-and-publications/forms-and-publications/mobile-plantoverturns/_nocache%3fsq_design_name=blank%26sq_paint_layout_name=pdf WorkSafe Guide & Industry Standard - Managing Safety on Piling Work & Foundation Engineering Sites WorkSafe Victoria has introduced a Guide and Industry Standard for managing safety on Piling Work and Foundation Engineering Sites. This industry standard provides practical guidance on health and safety to the piling and foundation engineering industry. It covers the safe operation and maintenance of PF equipment, and training of employees. It sets out industry-wide guidelines for Page 6 of 7
establishing and maintaining a safe working environment wherever PF plant and equipment is used. The industry standard is based on the current state of industry knowledge and construction methods. It is not intended to exclude other methods or processes that meet the requirements of providing a safe workplace. It is also not intended to be an all-encompassing design, maintenance and operation manual. A copy of the Guide may be found at: http://www.worksafe.vic.gov.au/ data/assets/pdf_file/0006/119724/piling-works- Industry-Standard-web.pdf Worksite Site Safety Update is produced to communicate industry safety information and initiatives within VicRoads and to our contractors. It is also circulated via the WorkSafe Safety Soapbox to industry. The content reflects civil road construction and maintenance safety and includes works conducted on or beside operational roads. The editor may be contacted at: michael.rose@roads.vic.gov.au Page 7 of 7