This section describes traffic management measures for:

• site safety and safe vehicle practices
• moving around hazards
• keeping safe speeds, distances and manoeuvres
• using safe and appropriately trained drivers
• selecting and maintaining suitable vehicles.

See also Section 8 for details on planning for roads and vehicle operating areas. For more in-depth information about safe practices for vehicles and mobile plant at work sites, see our good practice guidelines for Managing work site traffic as well as quick guides on Seatbelts and on Safe reversing and spotting practices

There are several ways vehicle activities can be a risk to workers at an extractives site. These include:

• the failure of a roadway (a collapse or slip)
• interactions between vehicles and pedestrians, vehicles and structures, or between two or more vehicles (vehicles carrying passengers, light and heavy vehicle interactions)
• the loss of vehicle control (the driver falling asleep or driver impairment, mechanical failure, loss of traction or tip over)
• the extent of hazards on the roadway such as sharp corners, steep inclines, drop-offs or traffic volume
• other hazards involving vehicles (fire, explosion, falls from height, tyre hazards or visitor vehicles).

In the design, layout, operation, construction and maintenance of every road within the extractives operation, you must give adequate consideration to:

• the grade and width of the road
• the drainage system
• mobile plant characteristics, including operator visibility, stopping distances and manoeuvrability
• operating speeds, driver position and remote-controlled mobile plant
• the characteristics of light and heavy vehicles to be used and their interaction.

You should also consider:

• the effect on road conditions caused by expected environmental conditions during operating periods (including time of day, weather, temperature and visibility)
• the impact of road design and characteristics, including gradients, width, camber, surface and radius of curves and intersections
• the impact of mine design, including banks, windrow design and steep drops adjacent to vehicle operating areas
• the volume and speed of traffic and the potential for interactions between mobile plant with different operating characteristics, including heavy and light vehicles
• the potential for interactions between mobile plant and pedestrians, including consideration of park up areas and driver access
• the potential for interaction between mobile plant and public traffic
• the potential for interaction between mobile plant and fixed structures, including overhead and underground power lines, tunnel walls and roofs.

On this page

• 14.1 Public safety
• 14.2 Site access: contractors, visitors and public
• 14.3 Overhead power lines
• 14.4 Other overhead structures
• 14.5 Reversing, manoeuvring and parking
• 14.6 Loading vehicles
• 14.7 Loading and storage of large stone slabs or blocks
• 14.8 Feeding crushers
• 14.9 Railway sidings
• 14.10 Safe drivers and vehicles
• 14.11 Inspecting and servicing vehicles
• 14.12 Tyre safety
• 14.13 Maintenance and repair of roads

14.1 Public safety

Consider the ways work on the site may create a risk not only to workers, but also to the public.

From a health and safety perspective it is good practice to divert public rights of way around mines or quarries. Where it is not possible, precautions should be implemented, based on a detailed risk assessment of the route and the area around the site. The precautions should be reviewed regularly.

Access to sites should be controlled to make sure unauthorised people cannot travel to a location where they may be at risk from site operations. This is particularly important for sites where there are sales to the public or in residential areas.

Control measures may include signage, automated barrier arms or worker- controlled areas (for example, a weighbridge operator).

Providing and maintaining suitable barriers around the site to discourage trespass may be appropriate. Trespass means entry to the site without express or implied permission. Barriers are appropriate where it is reasonably foreseeable that members of the public, including children, are likely to trespass on the site, and could suffer injury if they did so.

The type of barrier required depends on the risks. In a rural area, where risk of public access is low, hedges trenches and mounds may be enough. In areas where there is evidence of persistent trespass, which places the public at significant risk, substantial fences may be needed.

Workers should be encouraged to report cases of trespass or evidence that people have been on the site. They should also be told what action to take if they discover trespassers.

Signage

Suitable signs warning people of the possible hazards at the site should be erected at entry points and, where necessary, along boundaries. Any signs should be maintained in a legible condition.

Examples of signs warning of hazards and prohibited zones are shown in Figures 63 to 65.

14.2 Site access: contractors, visitors and public

On entering the site, vehicles and pedestrians should be directed to a safe area, unless instructed otherwise. This is usually achieved by signage, but may include road marking, footpaths or barriers. Allow sufficient parking spaces for workers and visitors.

Where site vehicles cross a footpath or turn from or onto a public road, consider public safety. This may involve discussions with the local council or New Zealand Transport Agency Waka Kotahi (NZTA) as part of the planning process.

Contractors and visiting drivers

Carefully consider contractors and visiting drivers, who may need to access operational areas. Assess their needs and induct them to ensure they are aware of the site rules and procedures and what is expected of them. Take steps to determine whether the visitor is competent to operate a vehicle at an extractives site.

For example, light vehicles (such as maintenance vans) invariably need to attend heavy vehicle breakdowns in operational areas. If possible, the heavy vehicle should be taken to a dedicated service area for the contractor to work away from operational areas. Give the visiting driver the traffic management plan, or escort them so their movements and operations are strictly controlled.

Regardless of the size of the site you should establish safe systems of work, which could include vehicle visibility (see Section 14.10), induction systems and signage as required.

Consider fully inducting regular visitors such as inspectors, contractors, couriers and delivery workers, so that they understand the hazards on site. All visitors should be escorted if not fully inducted to the site.

See also Appendix E for more information of overlapping duties.

Pedestrian separation

Pedestrian activity in operational areas should be restricted, wherever reasonably practicable, especially when it is dark. Workers should not enter operational areas as a pedestrian unless authorised to do so.

Pedestrians should use separate routes wherever practicable, for example pedestrian-only areas and safe, designated pedestrian routes (see Figure 66). Other control measures may include using light vehicles to transport workers to their place of work, or only allowing pedestrians to enter areas when vehicles are stationary (such as lunch breaks). Where separation by time is used as a control, check pedestrians have moved out of the area before operations begin again.

For smaller sites, or where only a few people are working, holding areas may be appropriate. For example, signage stating visitors are to remain at the site hut until authorised to proceed.

Often heavy vehicles park near workshops or staff rooms, so the interaction of pedestrians should be carefully managed by designated walkways and separation barriers.

14.3 Overhead power lines

Overhead power lines on a site are likely to pose a significant risk unless they are sufficiently high enough so that vehicles and equipment cannot approach or contact them. Vehicles do not need to strike the overhead lines for injury to occur – electricity can arc a significant distance depending on the voltage and conditions, so maintaining clearance distances is very important.

The most effective way to prevent harm from contact with overhead lines is by not carrying out work where there is a risk of vehicles making contact with or closely approaching the power lines. Roads should be routed to avoid them. If there is a risk, and the road or working area is permanent (or long-term), consult its owner to find out if the line can be permanently diverted away from the work area or replaced with underground cables.

The standard AS/NZS 3007:2013 Electrical equipment in mines and quarries – Surface installations and associated processing plant has further information to inform the risk assessment relating to power lines.

If it is not practicable to eliminate this risk, minimise the risk as far as reasonably practicable. When there is a possibility that a vehicle could reach the danger zone around the cables, use precautions such as those illustrated in Figure 67.

During the risk assessment, consider the possibility of vehicles travelling with a raised tray. A risk assessment is required to enable the development of the electrical engineering plan. Overhead power lines will be a part of that plan as well as roads and other vehicle operating areas.

Approach distances vary with the voltage of the power line. It is best to have a blanket single distance for your extractions site. For circuit voltages up to 110kV an accepted distance is no closer than 4m to the overhead power line. For circuit voltages above 110kV the minimum safe approach distance is 6m. For more information on approach distances see the New Zealand Electrical Code of Practice for Electrical Safe Distances (NZECP 34).

Where vehicles or mobile plant are likely to be used near overhead power lines, a permanent sign should be installed in a visible place as near as practicable to the driver’s position. The sign should be maintained in a legible condition and must state ‘Warning: Keep clear of power lines’ and include the distance to, and the voltage of, the power lines. For mobile crushers or transportable conveyors, the sign should be installed in a clearly visible place at each towing point and adjacent to driving controls.

If work needs to be carried out below power lines and it is possible that vehicles could reach into the danger zone, the lines should be isolated and earthed before work begins. If this is not practicable, physical safeguards such as chains on the booms of excavators may be required to prevent vehicles reaching into the danger area. Written consent is required from the line owner before any work is carried out.

If the operation changes the type of vehicle normally used, or a contractor’s vehicle is brought onto site, a risk assessment should be carried out to determine if contact with conductors is a potential risk.

Emergency procedures should outline what to do in the event of contact with an overhead power line (see Section 3). The procedure should include the operator not exiting the plant and the vehicle being isolated, to manage the potential risk of electrocution or tyre explosion in the procedures. Most power line asset owners have information available on their websites for working around overhead and underground power lines. One example is available from Vector at Safety near our networks(external link)

14.4 Other overhead structures

Measure and record the vertical clearance under overhead obstructions on routes. Take into account any underhanging lighting, ventilation or other service features, which are often added after the initial design. Routes used by vehicles should allow for sufficient overhead clearance. Vehicle routes should also avoid anything that might catch on or dislodge a load.

Protect any overhead obstructions (such as electric cables, pipes, conveyors or walkways) using goalposts, height gauge posts or barriers.

Give clear warnings of any limited width or headroom in advance and at the obstruction itself such as signs or audio warnings. Position these warnings at a sufficient distance from the structure so any vehicles can stop in sufficient time if they are oversize (see Figure 68). For more information about signs see Section 14.1.

14.5 Reversing, manoeuvring and parking

Reversing is hazardous because the driver has reduced visibility and is in an awkward driving position.

The most effective way of reducing reversing incidents is to use one-way systems and turning bays. Where this is not practicable, organise sites to keep reversing to a minimum. Where reversing is necessary, you should consider:

• ensuring adequate visibility for the driver
• installing engineering control measures (collision avoidance equipment)
• installing reversing cameras, proximity detection equipment and reversing alarms (see Section 14.10)
• providing safe systems of work
• providing adequate supervision and training.

Where safe reversing relies on reversing aids (such as reversing cameras) the vehicle should not be used if they are defective. Temporary control measures could be used to ensure safety (for example, using a spotter).

When it is dark, site lighting and vehicle lights should provide sufficient light for the driver to see clearly when reversing.

No single safeguard is likely to be sufficient on its own during reversing. Consider all the relevant precautions together (see Table 12).

Spotters

A spotter’s (or signaller’s) job is to guide drivers and make sure reversing areas are free of pedestrians or other hazards.

If you are using spotters, make sure:

• only trained spotters are used
• they are clearly visible to drivers at all times
• a clear and recognised system of communication is adopted
• they stand in a safe position throughout the reversing operation.

The PCBU must establish a safe system of work so anyone leaving a vehicle does not enter a hazardous area. This includes when operators are undertaking daily start-up inspections and shift changes.

Following distances

If a vehicle follows another vehicle too closely, an accident can occur if the driver in the trailing vehicle does not react as fast as the lead driver, or if the trailing vehicle cannot stop as effectively as the lead vehicle. You should have a safe system of work for vehicles following one another at a safe distance.

There are many factors that contribute to the necessary following distance. As vehicle speeds increase, the following distance should be lengthened to provide the necessary level of safety. Drivers should increase their following distance in conditions where visibility is reduced (such as fog), or when road conditions may result in a longer stopping distance (like those in wet weather).

Consider the speeds on both level roads and gradients, and establish following distance rules that provide for safe distances in all situations, with loaded and unloaded vehicles.

The established following distance rules should be kept in the site Traffic Management Plan or the Roads and Other Vehicle Operating Areas PHMP.

Visual aids can be used to determine following distances (for example, spacing road marker pegs at the site’s following distance rule).

Stopping distances

Three key factors determine the minimum stopping distance a vehicle requires:

1. the distance travelled during the operator’s reaction time
2. the distance travelled during brake response time
3. the distance the vehicle travels before coming to a s stop.

Quite often the Original Equipment Manufacturer (OEM) will only specify braking distance as specified in factor 3.

The minimum stopping distance can be calculated by adding the above three factors together. Gradients and wet conditions will also have a significant effect on factor 3, and they should always be factored into the calculations provided in OEM braking data.

The load on a vehicle, traction, and how the brakes have been applied (soft, medium, hard) also affect the stopping distance of a vehicle.

In areas where excessive stopping distances are calculated, speed restrictions may be required to make sure the final calculated stopping distance meets acceptable operational requirements.

Parking

Vehicles should be parked on level ground wherever practicable to eliminate the possibility of the vehicle inadvertently being set in motion. If it is not practicable to park a vehicle on level ground, prevent the vehicle from accidently moving by making sure the wheels are secured, chocked, blocked, angled against a suitable bund, or parked with wheels in a purpose-built contour.

Develop a safe system of work for leaving a vehicle unattended. For example, requiring drivers to switch off the engine, remove the ignition key, and apply all brakes. For mobile plant this may include lowering ground engaging equipment (excavator buckets, dozer blades, ripper teeth and scraper bowls) to the ground. Vehicles should never be parked in the swing radius of an excavator or the manoeuvring zone of other operational vehicles, unless in accordance with a safe system of work.

When it is necessary to park light vehicles close to heavy vehicles (for example, for maintenance purposes) the heavy vehicle should be parked before the light vehicle enters the area. The heavy vehicle should remain immobilised throughout the operation. The light vehicle should be parked in an area that is either inaccessible to the heavy vehicle or in a position where the heavy vehicle operator can see the light vehicle.

Site operators should ensure vehicles are only operated by competent people unless adequately supervised. Mine and quarry operators must ensure mobile plant is only operated by competent people, who are authorised in writing. This may mean ensuring keys, or any other devices for starting vehicles or mobile plant, are in a secure place while parked.

You should establish a safe system of work so anyone leaving a vehicle does not enter a hazardous area. This includes when operators are undertaking daily start- up inspections and shift changes.

Access and egress to heavy vehicle working areas

For access to heavy vehicle working areas, use walkways wherever practicable. Walkways should be made of slip-resistant grating (with enough space for mud or oil to pass through the grate and away from the walkway surface) or another slip-resistant material.

To prevent thrown mud from making them slippery, position walkways, steps, ladders and handrails away from wheels if possible.

Top and middle guard rails may be needed to protect people when they are standing or crouching. Consider collapsible rails.

Vehicle owners should consider fitting guardrails if they are not already present (see Figure 69). If features are retrofitted to existing vehicles, the alterations should not affect the structural integrity of the vehicle or the visibility of the operator.

Climbing on or off vehicles

Access to heavy vehicles should be by a well-constructed ladder or steps. Ladders or steps should be well built, properly maintained and securely fixed. Where steps or ladders extend to the ground, the use of interlock systems is required to prevent the vehicle moving or starting until the ladder or step has been correctly stowed.

Avoid using suspended steps wherever practicable. If they cannot be avoided, use rubber or cable suspension ladders, not ladders made of chains. Ladders and steps should slope inward towards the top if this is reasonably practicable. They should not slope outwards towards the top.

Rungs or steps on vehicles should:

• be level and comfortable to use
• have a slip-resistant surface
• not allow mud, grease or oil to build up dangerously (grating could be used to allow things to pass through a step).

The first rung or step should be close enough to the ground to be easily reached – ideally about 40cm and never more than Place ladders or steps as close as possible to the part of the vehicle requiring access.

Opening (and holding open) a cab door on a vehicle should not force a driver to break the ‘three-point hold’ rule or to move to an unsafe position.

Vehicle owners should consider retrofitting safer access ways to eliminate the risk of falling (see Figure 70 and Figure 71).

14.6 Loading vehicles

Loading, for the purposes of this section, refers to the loading of vehicles with excavated material by mobile plant. For information on safety when loading mobile plant or equipment (or other loads) from transporters or trucks, see The Truck Loading Code. For information on loading floating plant, see Section 12.3 and 12.4.

Depending on the nature of the site, loading may be into haul trucks, truck and trailer units, utility vehicles or car trailers (for example, where selling of product is directly to the public).

Loading zones

It is recommended that the loading zone (or prohibited zone) be a minimum of 6m around the truck, trailer or mobile plant. This zone may need to be larger, depending on the visibility of vehicles or traffic movement associated with loading (see Figure 72).

In addition to the loading zone, restricted zones should be established based on a site-specific risk assessment, which considers the movement of vehicles associated with loading.

The entry of any vehicle (other than those being loaded) or pedestrians into a loading zone while excavation and loading operations are active should be prohibited.

Determine a safe system of work which specifies communication protocols for vehicles entering the loading zone (to be loaded). For example, the system could specify contact is made with the mobile plant operator to request permission to proceed. On larger sites this may be coordinated by a supervisor or other designated person in control of traffic movements.

The safe system of work should also specify steps to be taken, including the immediate suspension of works, if a vehicle or pedestrian enters the loading zone without prior permission.

Loading operations

PCBUs must identify hazards and, where eliminating risks is not reasonably practicable, minimise those risks through control measures. Insecure loads and overloaded vehicles can present a significant hazard whether on a public road or a road within the confines of the site.

The Land Transport Act 1998 contains the load security legislation for vehicles driven on public roads. It provides strict liability for offences involving insecure loads and loads falling from vehicles. The Truck Loading Code details the general requirements that must be met to ensure a load cannot fall, and it applies to the operator or any person loading the vehicle.

Refer to the original equipment manufacturers loading instructions and weight limit recommendations.

Loads must be secured and remain safe while loading, while the vehicle is being driven, and during unloading. When loading or unloading, the vehicle should be level, stable and stationary. Apply all vehicle and trailer brakes, and follow these principles:

LIGHT VEHICLES

• Spread loads as evenly as possible during Unbalanced loads can make the vehicle or trailer unstable, or overload individual axles.
• Prohibit loading over cabs unless the driver is out of the vehicle and away from the loading zone (in a safe area).
• Avoid loading to the back of the trailer as this can cause the trailer to tip backwards (especially for single-axle trailers). This can reduce the grip the vehicle has on the road surface, as the wheels are lifted away from the
• Balance loads across the axle (or axles) of a drawbar so coupling or uncoupling can be managed easily and safely, and the trailer is stable when being transported.
• Wherever possible couple (or uncouple) drawbar trailers unloaded, as this makes them easier to handle and generally safer to work with.
• Select suitable mobile plant or purpose-built devices (hoppers) that reduce the risks to other vehicles or pedestrians. 

ON-ROAD VEHICLES

• Spread loads as evenly as possible during loading, based on advice from the driver, and do not load over Unbalanced loads can make the vehicle or trailer unstable, or overload individual axles (see Figure 73).
• All drivers (and where applicable, passengers) should remain in the vehicle during loading.
• If the load is to be covered, an on-vehicle covering device that can be worked from ground level or a safe place higher up should be Alternatively, a load covering platform or gantry should be used.
• As loose loads normally rely on the vehicle body for restraint, it is extremely important to make sure all body-to-chassis attachment points (‘U’ bolts, hinge pins, hinge pin brackets and so on) are secure, and the attachment points and body are in sound condition.
• Doors to bulk bins must be closed to avoid loose bulk loads from being blown out.
• When travelling on a public road, loose bulk loads should be covered whenever there is a risk of load shedding due to wind action or Body work should be kept in good condition to minimise hazards during transportation. This applies particularly to badly fitted tail gates that permit gravel and stones to fall to the roadway. Loose bulk loads being transported in a vehicle on a public road without a tarpaulin fitted, should at no time reach higher than 100mm below any side of the vehicle (see Figure 74).
• Body height extensions (hungry boards) should only be used where conditions and type of load In these circumstances, supports should be adequately fixed to the existing body. It is not adequate to rely on the load within the parent body of the vehicle for support. Where necessary, tie- chains should be used transversely at the top of body extensions to prevent sideways spread.

OFF-ROAD VEHICLES

• Spread loads as evenly as possible during Unbalanced loads can make the vehicle or trailer unstable, or overload individual axles.
• Prohibit loading over the cabs.
• All drivers (and where applicable, passengers) should remain in the vehicle during loading.
• Loads should not be dropped from height to avoid people in the cab being thrown around or injured.
• If particularly large rocks are being loaded, placing a fine material bed will provide some cushioning and stability.
• The placement of loads should ensure they are secure.
• The excavator or loader should be matched to the size of the truck being loaded.

Covering loads

Loads should be covered whenever there is a risk of load shedding due to wind action or movement when travelling on a public road, in line with The Truck Loading Code – specialised requirements (loose bulk loads).

Covering loads or removing covers can be hazardous, especially when carried out manually. Consider the risks associated with load covering and take effective measures to make sure covering and uncovering loads is done as safely as possible. Consider the types of loads and vehicle, how often covering or uncovering happens, and take other specific characteristics of your workplace into account.

There are several options for covering loads, but some are better than others. A method of covering and uncovering that does not involve getting on to the vehicle or even touching the cover should be the first choice.

A hierarchy of control measures for load covering could involve this sequence of considerations:

1. Leaving the load uncovered if it is safe to do so.
2. Using automated or mechanical covering systems that do not require people to go up on the vehicle (see Figure 75).
3. Using manual covering systems which do not require people to go up on the vehicle (see Figure 76).
4. Using work platforms to provide safe access to carry out covering from the platform without having to access the load (see Figure 77).
5. Using gantry or harness systems to prevent or arrest a fall (see Figure 78).

Consider the following points regardless of which method of covering you use:

• Do not overload the vehicle and try to load evenly to avoid the need for trimming. Load evenly along the length of the vehicle (not in peaks) or use a loader to pat down the load to flatten peaks.
• Train and instruct staff on safe systems of work (and provide refresher training where necessary). Supervise and monitor covering and uncovering activities.
• Regularly check covers are in good condition and replaced when necessary. Visually check straps and ropes used for pulling and securing the cover.
• Regularly inspect, repair and maintain covering mechanisms, platforms, gantries and fall-arrest equipment (such as harnesses and lanyards).
• During loading, unloading and covering, consider vehicles used by workers of more than one company ‘shared workplaces’ and arrange for suitable control measures to be followed by everyone concerned.
• Ropes, straps and covers can snap or The driver should avoid leaning backwards when pulling the cover tight.
• Park vehicles on level ground, with parking brakes on and the ignition key removed.
• Cover vehicles before leaving the site.

Whatever way it is done, carry out covering and uncovering in designated places, away from passing vehicles and pedestrians and, where possible, sheltered from strong winds and bad weather.

Weight limits

Maximum vehicle and axle weights must never be exceeded. Overloaded vehicles can become unstable and difficult to steer, or less able to brake.

Extractives operations with roads and other vehicle operating areas must include in their PHMP the maximum load that may be carried or towed by vehicles and equipment (whether by reference to weight, dimensions or other criteria) on their roads and other vehicle operating areas.

14.7 Loading and storage of large stone slabs or blocks

Transporting and storing large stone slabs or blocks carries a high risk of serious personal injury if not done safely. Depending on the type of rock, slabs or blocks can fail during handling in unpredictable ways. For example, natural stone can be fissured and may crack or shatter unexpectedly during handling. Due to their size and weight, such slabs or blocks are potentially unstable.

To ensure the safety of workers, you should determine a safe system of work that includes:

• prohibition zones – not allowing people into an area where a slab or block may fall during transport or lifting
• written work instructions (or standard operating instructions) – workers should be given appropriate information, instruction and training on the dangers of large stone slabs or blocks and the need to follow safe systems of work
• adequate supervision by a competent person
• always restraining slabs or blocks during loading or unloading operations (whether from vehicles or from storage). This should include attaching and detaching straps, lifting slings and so This is especially important when people may be in the hazardous area where a slab may fall during lifting, and when loading or unloading vehicles (due to the variable and sometimes unpredictable effects of road camber or vehicle suspension)
• using only appropriate loading equipment (such as forklifts and cranes) that are designed for the lifting requirement and are properly maintained and operated by competent personnel
• providing, maintaining, using and inspecting appropriate certified lifting equipment and PPE
• making sure loads are secured while being transported.

When using rack type storage systems, they should be designed and certified to prevent slabs toppling over or slipping out from the base. Traditional A-frame storage is not suitable in this context unless modifications have been made to achieve this goal.

14.8 Feeding crushers

If the crusher is to be fed directly by a loader, truck or excavator, then:

• standing pads should be suitable (stable) and high enough for the operator to monitor the feed hopper from the cab
• keep the ramp wide enough to allow for adequate edge protection on either side of the ramp as well as the travel of the vehicle when using wheeled loaders or trucks
• the maximum gradient of the ramp should be within the capability of the loading vehicle
• the last few metres of the ramp should be level, so the vehicle is not discharging uphill. This helps operators monitor the The vehicle will also be more stable
• make sure pedestrians and obstructions are kept out of the excavator swing radius or loading area.

14.9 Railway sidings

Where railing sidings enter a site, you should:

• where practicable, have a means of locking siding entrances
• where practicable, have tracks separated from other operational areas
• have a safe system of work for communication about train arrival times and days (for example, having the rail operator advise of trains entering the site at least 24 hours prior)
• make sure tracks are not obstructed and are kept clear of debris
• where appropriate, put signage in place advising of train arrival and other hazards.

The siding is likely to require a rail licence under the Railways Act 2005 and related safety case requirements. Operators should contact NZTA for more information.

14.10 Safe drivers and vehicles

Drivers should be competent, or adequately supervised, to operate a vehicle safely and should receive appropriate information, instruction and training for the make and model of vehicles they use. It is particularly important that less experienced drivers are closely monitored following their training to make sure they work safely.

Protocols should be established to ensure drivers and passengers wear their seatbelts. Past accidents have shown that staying in the cab with the seatbelt fastened is the best way to avoid a serious injury or death when a vehicle loses control.

Training and competency of drivers

Drivers must be licenced to drive on a public road. The licence must be appropriate for the class of vehicle being driven. Periodically check that your drivers have current licences.

Where drivers are required to drive on roads within the mine site, employ systems and procedures for training and verifying the competency for people to drive on site. This verification of competency records should be kept on site as a part of the training records. Choose a driver training system that follows a recognised standard.

Training requirements will depend on an individual’s experience and training they have previously received. Risk assessment should help decide the level and amount of training a person receives. In general, newly recruited drivers have the greatest training needs, but there should also be a reassessment programme for more experienced drivers. It is preferable that the person undertaking the assessments receives training to be an assessor.

It is important to assess information provided by newly appointed drivers, particularly in relation to training and experience. Monitor them on site to establish both their actual level of competence and any further training needs.

Keep a record of training and licences for each driver to help ensure the most appropriate person is allocated a particular task and identify those requiring refresher training.

Excavations operators must authorise mobile plant operators in writing. Authorisation to operate should be for every individual mobile plant.

Fitness to drive

A person’s fitness to drive a vehicle should be judged on an individual basis, but the aim is to match the task requirements with the fitness and abilities of the driver.

Pre-employment health assessments and on-going health assessments should include assessment and monitoring that relates to a person’s ability to safely drive a vehicle (and undertake any associated tasks).

Site health control measures may require random alcohol and drug testing. For detailed advice on medical standards of fitness to drive, see the NZTA website.

Vehicle suitability

Vehicles should be suitable for the type of work being done and the place they are being used. Selecting suitable vehicles can reduce or eliminate many risks at the site. It is generally much easier and cheaper to start with the right vehicle than to modify it later. Before purchasing a vehicle, you should at a minimum consider:

• the effectiveness of the braking system, bearing in mind the slopes it is expected to work on
• adequate visibility in all directions for the driver
• stability under all foreseeable operating conditions
• protection for the driver and any passengers from falling objects (falling object protective structure (FOPS)), overturning (roll-over protective structure (ROPS)) and seatbelts. Further information is available in the Approved Code of Practice for Operator Protective Structures on Self-propelled Mobile Mechanical Plant
• safe access and egress to and from the cab and other areas of the vehicle where access may be required
• adequate fall from heights protection when getting in and out of the cab, as well as around working areas at elevated heights (such as engine bays)
• engine firewall and fire suppression equipment
• lights, windscreen wipers, horns and other warning devices
• guarding for dangerous parts during use or maintenance work
• protection for the driver and any passengers from rain, high and low temperatures, noise, dust and vibration
• suitable seating for the driver and any passengers
• maximum loads that may be carried or towed.

Where vehicles are not fitted with safety features, consider retrofitting where your hazard identification and risk assessment process has recognised a significant hazard (for example, fitting reversing cameras). Consider emerging technology as part of the risk assessment control measures, such as safe approach signals, laser delineation systems, birds-eye 360° camera views and collision avoidance systems. Data acquisition systems that measure factors such as loading, speed, tip angles or braking are good management tools to assess driver behaviour.

For vehicles expected to enter sites when it is dark (whether or not work is scheduled to take place) additional supplementary lighting should be provided (such as forward and rearward facing spotlights) or additional vehicle-mounted work lights.

Any permanently fitted lights must comply with the Land Transport Rule: Vehicle Lighting 2004 when being driven on public roads.

Driver visibility

Many vehicles have substantial blind spots, not only immediately behind the vehicle, but also alongside and immediately in front of it. When you introduce a vehicle to the site, complete a risk assessment to identify the blind spots. Improving visibility requires a combination of approaches such as reversing cameras, collision avoidance systems, proximity sensors and mirrors.

Studies suggest that when used appropriately (such as drivers glancing at the collision avoidance system at appropriate moments) reversing cameras can successfully mitigate the occurrence of reversing crashes, particularly when paired with an appropriate audible warning system.

Accidents can occur when vehicles drive off or turn while a pedestrian or vehicle is passing or parked in a blind spot. As a guide, the driver should be able to see a 1m high object 1m away from any point within a vehicle. The driver should be able to detect the presence of other vehicles and pedestrians in their intended line of travel.

There should be a procedure to be followed before a vehicle drives off, for example:

• moving from being parked overnight or otherwise not in use – a single beep from the horn with a five second delay before driving off
• moving from an operational area – two beeps from the horn, with a five second delay before driving forward
• moving in reverse – three beeps from the horn with a five second delay before reversing. 

A CLEAR VIEW

Drivers should not place items in the windscreen or in the way of mirrors or monitors, where they might impede visibility from the driving position. The area of the windscreen that is kept clear by the wipers should not be obscured, nor should the side windows. Windows and mirrors should be kept clean and in good repair. Dirt or cracks can make windows or mirrors less effective. If necessary, fit additional side-mounted mirrors to increase the driver’s visibility (see Figure 79).

REVERSING ALARMS

Reversing alarms warn anyone in the vicinity that the vehicle is in reverse gear. They still rely on the driver having a clear view and the pedestrian or other vehicles moving out of the way.

Reversing alarms may be drowned out by other noise, or may be so common on a busy site that people do not take any notice of them. Using reversing alarms may be appropriate (based on your risk assessment), but will likely be most effective when used with other measures. Alarms can have different warning tones to meet environmental compliance requirements and still be effective in the intended zone of influence.

COLLISION AVOIDANCE AND PROXIMITY DETECTION EQUIPMENT

Collision avoidance equipment warns the driver of fixed obstacles or other vehicles along the route and stops the vehicle from colliding. Collision avoidance systems usually use GPS or local area wireless technology (Wi-Fi or Bluetooth) to determine vehicle position, speed and heading. Vehicle locations and paths are calculated and sent by radio link to all other outfitted vehicles in the area. Where two or more vehicles may collide, audible and visual warnings are sent to the drivers.

Proximity detection equipment warns the driver of the presence of people or objects in the immediate vicinity. Some proximity detection equipment is also able to stop a vehicle if it predicts a collision with a person, but drivers should always act to stop the vehicle from collision. 

CLOSED-CIRCUIT TELEVISION

CCTV cameras can be mounted on the front, side and rear of a vehicle. Images are relayed to a screen located inside the cabin (see Figure 80). Some cameras are equipped with infrared illuminators, so the driver has a comprehensive view even when it is dark. Birds-eye view systems are now available that provide the operator with a 360° view of the vehicle from above. Forward facing and driver facing cameras record actions if sudden braking occurs.

Thermal imaging systems are also available and may be suited to sites where night operations are a concern.

Visibility of light vehicles

Light vehicles are at risk of being crushed by heavy vehicles. They should be kept away from areas where heavy vehicles operate.

Where this is not practicable, they should be fitted with rotating or flashing beacons, high visibility ‘buggy whip’ flags, high visibility and reflective markings or other appropriate measures. This makes them readily visible to drivers of other vehicles. The use of vehicle hazard lights alone is not deemed adequate.

For light vehicles expected to enter areas where heavy vehicles are operating, consider the following control measures during your risk assessment:

• Establish exclusion zones around heavy vehicles.
• Heavy vehicles should remain stationary when light vehicles are within exclusion zones.
• The impact on environmental conditions on visibility (for example, darkness, fog or rain).
• Fit vehicles with rotating or flashing orange warning lights, visible 360° from the vehicle, unless multiple lights are fitted to cover blind spots and fit with reflective strips.
• Fit radios so drivers can communicate with site supervisors or directly to heavy vehicle drivers.
• Develop a positive response communication protocol to ensure the heavy and light vehicle operators are clear about vehicle This typically involves deciding on a signal to request and receive an approval to move the vehicle.
• Fit a warning flag (buggy whip flag) which can be seen by the operator of the tallest vehicle.
• Fit clearly visible numbering, or an alternative form of positive identification, as an aid for two-way communication between heavy vehicle and light vehicle drivers.

Light vehicle visibility control measures should apply to all light vehicles (for example, contractor or visiting drivers where they are required to enter operational areas).

Any permanently fitted lights, retro-reflectors or retro-reflective material must comply with the Land Transport Rule: Vehicle Lighting 2004 when driving on public roads.

Protection of drivers, operators or passengers

OPERATOR PROTECTIVE STRUCTURES

Operators of heavy vehicles are at high risk of serious or fatal injury by crushing if their vehicles roll over, tip on to their sides or objects enter the cabin. Generally, the risk depends on the terrain and task. For example, there is a low risk on flat, stable ground, and high risk on steep or unstable ground, or on work adjacent to embankments, excavations or working on top of old mine workings.

Fitting roll-over protective structures (ROPS) and wearing a seatbelt can reduce the risk of serious or fatal injury in the event of a roll-over or tip-over. Where there is risk of objects falling onto the operators or entering the driving position (such as rock falls) the operator also needs the security of a falling object protective structure (FOPS).

Extractives operations with a mechanical management plan should address the fitting of devices to protect the operators of mobile plant, including roll-over protection and falling object protection.

For more detailed information on design and types of operator protective structures, see the Approved Code of Practice for Operator Protective Structures on Self-Propelled Mobile Mechanical Plant

SEATBELTS

All drivers and passengers should wear appropriate seatbelts. Seatbelts should be checked immediately if:

• the buckles are not working properly
• the belt is damaged or faded
• the belt starts to fray
• in-use alarms are defective.

Specific legal requirements for safety belts have changed over time and differ depending on the age and type of vehicle. The type of belt has also changed from static belts to retractor belts. For more detailed information on seatbelts for vehicles, see the NZTA website.

Full harness seatbelts assist the driver to stay within the seat and reduce the effects of body stressing. There are systems available that monitor whether the driver is wearing a seatbelt.

TRANSPORTING PEOPLE

People should only be transported in vehicles fitted with seatbelts and designed to carry passengers. These vehicles should also ensure driver visibility.

Wherever practicable, carry loads separately from passengers. If the cabin is not separate from the load area (for example, a van), fit a bulkhead or cargo barrier between the load compartment and the cabin. This should be strong enough to withstand a load shifting forwards in an emergency.

Secure small equipment (such as fire extinguishers or tools) which may become missiles in the event of a collision. 

VEHICLE FIRES

Typical causes of fires on or in vehicles include component failure and poor or inadequate maintenance. When completing a risk assessment for prevention of fires consider:

The design – for example:

• when replacing hydraulic components, make sure they are ‘like for like’ and suitable for Always consult the original equipment manufacturer (OEM) before making changes
• any maintenance, installations or design modifications that are undertaken off-site are verified before use and are equivalent to the OEM’s standards and design
• implementing quality checks or audits by OEM-authorised service providers periodically as a cross check for site maintenance
• using low flammability hydraulic Note that low flammability and mineral hydraulic fluids should never be mixed. If you are replacing one with the other, ensure a flushing product is used and no residual product remains.

The installation – for example:

• properly fitting any attached or in-situ hoses with approved OEM components
• maintaining hydraulic equipment with the appropriate fit-for-purpose tools
• routinely checking hose clamps for security
• routinely checking for wear of hoses or rigid pipes underneath clamps
• using fire resistant hoses and high temperature tolerant hoses designed for oil operating temperatures greater than 150°C
• installing and evaluating insulation around hot components or insulating hoses near hot components and upgrading to braided armour type hoses
• protecting wiring against fire and making sure connections are appropriate to OEM requirements and are suitably located
• the location and rating of protective devices such as fuses, solenoids and non-return valves.

Inspection and maintenance – for example:

• completing pre-start checks for locating and acting on oil leaks, sprays, stains and bird nests
• the maintenance work order system includes the correct selection, integrity and testing of control measures
• using thermal imaging equipment to detect hot spots and high temperature areas of plant during maintenance programmes
• routinely washing, cleaning, and checking hoses for any sources of rubbing, oily mist or leaks
• carrying out periodic checks on hydraulic braking systems to ensure sound operation, including bearings, brake drums, rotors and callipers
• routinely checking electrical wiring, including insulation
• routinely checking solenoid connections for corrosion and replacing or checking at set engine hours or according to OEM recommendations
• protective devices for solenoids such as fuses.

Emergency preparedness – for example:

• installing suitable and sufficient firefighting equipment (such as fire extinguishers). The type of fire extinguisher will depend on the class of fire you are most likely to For example, powder ABE fire extinguishers are suitable for flammable and combustible liquids, flammable gases, and energised electrical equipment
• communication of fire-related events, maintenance incidents and subsequent attendance and associated follow-up is clear to workers
• fitting appropriate automatic or manually-operated fire Note the fitting of fire suppression systems is covered by the standard AS 5062:2016 and requires a competent installer that understands the fuel sources and where best to position nozzles to ensure effective suppression
• fitting engine or fuel pump shutdown systems
• fitting mobile plant with a battery isolation switch and, where practical, a fuel isolation system.

Cleaning trailers fitted with tailgates

There have been fatalities and serious debilitating injuries caused by swinging tailgates hitting drivers while they have been cleaning out their trailers. The extractives operator should provide appropriate washing facilities for trucks in safe areas and prohibit all work that places a worker between the trailer body and the tailgate. Trailers should have purpose-built access points and tailgates fitted with positive secondary support mechanisms.

The extractives operator should communicate their site-specific requirements to all drivers, including site drivers and external trucking PCBUs. For more information on overlapping duties for PCBUs, see Appendix E.

14.11 Inspecting and servicing vehicles

Vehicles at extractives sites work in harsh environments and need effective maintenance to avoid developing defects. Establish a programme of daily visual checks (or pre-start checks), regular inspections and servicing schedules according to the original vehicle manufacturer’s (OVM) instructions, and the risks associated with the use of each vehicle.

Inspections and maintenance should include, where appropriate:

VEHICLE CONTROL

• Braking systems
• Steering
• Tyres, including condition and pressure
• Safety devices such as interlocks 

DRIVER SAFETY

• Seats and seatbelts
• Mirrors, cameras and other visibility aids
• Lights and indicators
• Warning signals
• Windscreen washers and wipers
• Firefighting equipment 

VEHICLE MAINTENANCE

• Condition of cab protection devices (such as rops and fops)
• Condition of tailgates
• Condition of hydraulic pipes and hoses
• Fluid levels
• Functional checks on the vehicle
• Other accessories such as quick hitches

Where vehicles are hired, determine who is responsible for maintenance and inspection during the hire period and make this clear to all parties.

Put in place a safe system of work that addresses issues such as safely blocking the vehicle and its attachments, isolating stored energy and preventing the vehicle from inadvertently being started. When using jacks they should be rested upon suitable load bearing substrata. Raised objects should be lowered wherever practicable (such as excavator or loader buckets).

Determine a procedure to address defects where they are found in vehicles or attachments. Such procedures could include:

• recording defects when completing daily visual checklists (pre-start inspections) scheduled inspections, daily visual checklists and maintenance logs
• establishing protocols for safety critical defects (such as when a vehicle should be removed from operation, time frames to fix specific defects). For example, how deep does a cut in the tyre need to be before it should be replaced?
• a system to isolate vehicles when safety critical defects are For example, keys or other starting devices removed and secured until repairs are started.

Maintenance under hydraulically raised parts of vehicles

Many vehicles use hydraulics to raise, lift or move material or parts of the vehicle (such as truck trays, front end loader buckets, excavator booms and drilling rigs). These raised parts have stored energy, and you must provide supports or other devices to prevent raised parts dropping or being lowered while workers are under them.

Consider:

• removing the elevated part before other maintenance work takes place (eliminate the hazard)
• fitting a restraining system to the elevated part
• fitting the tray or bucket with a built-in prop
• ensuring restraining system controls are clearly marked and shrouded or protected from accidental operation
• fitting hydraulic cylinders with centre valves. 

Brake testing

A suitable inspection scheme should be in place to ensure brakes are in good condition at all times. This is often combined with other maintenance work.

Electronic brake testing equipment is available to regularly and accurately measure brake performance (for example, an electronic system may be permanently fitted in a haul truck). This will show deficiencies in the brake system before they become a problem. The site Health and Safety Management System should require operation, monitoring and maintenance of brake systems according to OVM recommendations, as a minimum.

It should be ensured that:

• the driver tests the brakes at the start of every shift (pre-start inspection), including the park brake and foot brake
• the condition of brake system components is monitored according to OVM’s recommendations, reducing the likelihood of catastrophic failure and ensuring they continue to function as intended
• brake system performance is tested according to OVM’s recommendations in both static and dynamic situations
• drivers and maintenance workers can access OVM operating and maintenance manuals at site as appropriate
• braking system repair, monitoring, inspection and testing records are readily available at site
• drivers and maintenance workers are trained in the relevant aspects of braking systems
• safety critical aspects of vehicle operation, including emergency braking systems, retarders and other control measures available in the event of engine failure (for example, accumulators), are incorporated into driver training and assessment processes, with appropriate input from competent maintenance workers
• operating and brake maintenance practices for contractors’ vehicles are not inferior to the vehicle maintenance practices adopted by the site
• contractors’ vehicles are not allowed to operate on site unless maintenance and testing records are checked to verify the integrity of brake systems
• brake maintenance, including processes used for contractors’ vehicles, is regularly audited for effectiveness
• if OVM manuals cannot be obtained (for example, due to the age of vehicle), prepare manuals so effective brake system operation and maintenance strategies can be Use people with appropriate skills and technical expertise to facilitate the process.

Brake system maintenance strategies

Correct brake system functioning depends on the condition of system components, which in turn depends on the quality of the maintenance. Any brake system maintenance strategy should focus on detecting and rectifying a defect before it results in a loss of brake function.

Brake system maintenance strategies should initially be based on the OVM recommended maintenance programmes, and on condition monitoring, inspection and testing schedules. OVM stipulated operating procedures and repair techniques help make sure brake system integrity is not compromised.

The OVM information should be stored, maintained, updated and be readily accessible by relevant workers, whether it is in hard copy, electronic copy, or on-line based systems.

Hazard identification and risk assessment aimed at improving brake system reliability should consider anything that could affect the safe operation of vehicles. This could include site conditions, maximum loads, operating speeds, operating grades, effects of heat fade, component failure, and loss of pressure.

Control measures may include more frequent component inspections for wear or damage, and regular brake performance verification techniques. These could include Dynamic Brake Testing (DBT), electronic brake test equipment and thermographic temperature profiling, to detect poor performance.

Remember that a positive DBT result does not necessarily verify brake system integrity or confirm the system has been maintained to OVM recommendations. It only indicates the brakes were effective at the time of testing.

In introducing a DBT programme, the risk assessment to determine appropriate control measures should consider, but not be limited to:

• OVM consultation on any deviations from the stated recommendations
• applying relevant brake performance testing standards or appropriate industry practice
• site facilities and limitations relating to surface, space, and controlling vehicles in case of brake failure during testing
• variations in test methodology and acceptance criteria for different vehicle types and categories (for more detailed information see AS 1-1995 Earth-moving machinery – Safety – Wheeled machines – Brakes)
• reliability of the DBT test instruments
• applicability and integrity of the standards, procedures and methods used to interpret the results
• training and competency of workers conducting the tests.

Industrial trucks and load shifting equipment (forklifts, mobile cranes)

Inherent instability and lack of traction of forklifts and cranes, particularly on ramps and slopes, present a challenging risk management task. Operators should understand the brake system design limitations and that brake system monitoring, inspection, testing and maintenance are appropriate for the risks in particular applications.

The Australian Standard AS 2359.13-2005 Powered industrial trucks – Brake performance and component strength provides guidance on methods for assessing and testing the performance and components of brakes fitted to industrial trucks with rated capacities up to, and including, 50t.

Safe forklift operation on gradients largely depends on the type, size and design of the forklift. Ask the OVM if you are unsure of the braking system’s performance capabilities.

14.12 Tyre safety

Large tyres and wheel assemblies are heavy objects, but when they explode, they are thrown violently by the force of the escaping compressed air. An exploding wheel is a high-speed projectile that can kill or seriously injure anyone in its path.

Tyre handling

The tyre and wheel assemblies of large vehicles are usually too heavy to be manually handled safely. The safe fitting and maintenance of large earthmoving tyres and wheel assemblies can only be undertaken using specialist tyre-handling equipment. Special attachments may be required on standard handling equipment (such as forklifts) to deal appropriately with large tyres and wheels.

A variety of tyre-handling attachments is commercially available for use with forklifts, hydraulic vehicle-mounted cranes and tyre handlers, loaders, integrated tool carriers (ITCs) and other multipurpose machines.

The responsible person should make sure the machines used are:

• fit for purpose
• safe to use
• adequately inspected and maintained, with appropriate records being kept.

Operators should be adequately trained and assessed as competent to operate the particular type of machine and tyre-handling attachment.

Robotic and remotely operated tyre- and wheel-handling equipment could be considered during the risk assessment.

Lifting tyres with a crane

When lifting and moving tyres as a freely suspended load, using a crane:

• make sure the rated capacity of the crane is appropriate for the weight of the tyre being lifted or moved
• make sure a mobile crane and its suspended load remain stable whether the crane is stationary or tramming
• maintain an exclusion zone around the work area
• never work beneath a suspended tyre
• stay clear of any slings being used
• do not use chains to lift or suspend a tyre
• avoid damaging the bead, by not allowing rope slings to rub against the bead area of the If a tyre must be lifted using a crane, use a wide fibre sling or belt to prevent damaging the bead.

Lifting with a forklift

When lifting and moving a tyre with a forklift:

• make sure the rated capacity of the forklift is appropriate for the weight with the mass of the tyre being lifted or moved
• consider the stability limits of the forklift and the ground conditions where it will be travelling with the load
• secure the tyre with suitably rated tie-down straps, as a minimum
• consider using a specifically designed rubber-coated cradle or slipper extensions on fork tynes to provide adequate support when lifting or transporting the tyre
• always lift the tyre at its outside circumference, never insert the fork arms through the centre of the tyre as this can damage the bead, resulting in premature failure when the tyre is inflated
• operate the forklift in reverse, if the load obstructs the forklift driver’s view, and enlist a spotter to assist with manoeuvring, or do both,
• consider equipping the forklift with reversing cameras or other proximity detection aids as part of the safe system of work.

Clamp-type tyre manipulators

When using clamp-type tyre manipulators:

• match tyre-handling attachments to multipurpose mobile plant (the combination of plant should be assessed and deemed safe to use)
• make sure that tyre-handling attachments are only used with machinery that is accepted by the manufacturer of the earth-moving machine and attachment
• verify the competency of the operator of the tyre-handling attachments
• consider safety factors in design between manufacturers and make sure the machines used are fit for purpose
• inspect the machinery and assess the job risks before commencing work, taking prevailing weather conditions into account
• park and isolate the machine on a suitable stable surface, at a safe distance from other activities
• based on a risk assessment, create a clearance zone large enough for the tyre handler to work and move
• operate the tyre handler within its rated capacity and according to the manufacturer’s instructions (a copy of the manufacturers operator manual, maintenance manual and logbook should be available to the operator)
• deflate tyres to the nominal handling pressure recommended by the site procedure for the task being undertaken or for storage
• make sure gripping pads have full contact with tyre treads before lifting
• if you are using a two-arm tyre handler to move tyres, travel at a safe speed with the tyre low to the ground and in the horizontal position, with the arms of the tyre handler tilted back
• only rotate the tyre into the vertical position when necessary. 

Working with compressed air

The eyes are particularly at risk when compressed air is in use, both from high-velocity air and from particles of dust, metal, oil and other debris, which can be propelled by the air. Suitable eye protection should always be worn.

Suitable overalls or other substantial clothing will protect the skin from fine particles and debris, provided they are not blown at a high velocity. However, overalls cannot offer protection against high-velocity air at close range. Particles can be blown through overalls and skin and into the body. Air can be blown into the bloodstream, causing swelling and intense pain, particularly if any cuts, punctures or sores are present, making entry easier. The air can be carried to the small blood vessels of the brain, lungs or heart, resulting in death. Workers should not use compressed air to dust themselves down.

All pressure gauges and control devices should be checked against a master pressure gauge at regular intervals or immediately after any heavy impact or other damage.

Compressed air hand tools, as well as compressors and associated equipment, should be maintained and checked regularly.

Tyre safety cages and exclusion zones

Most car or light vehicle wheels and tyres are strongly constructed and have a small internal air volume. They therefore do not require high pressures. Such tyres pose minimal risk to the service person and, if correct fitting procedures are adhered to, problems would not normally be expected. However, some light vehicles have divided wheels that require cage inflation. In general, inflate light vehicle tyres with the jaws of the tyre-fitting machine restraining the wheel.

It is strongly recommended that all tyres, including small units, be inflated within a suitable restraint.

Tyres on split-rim and detachable-flange wheels should be contained by a cage guard, or other suitable restraining device, when being inflated after being dismantled or repaired.

Tyres that have a large volume, or are inflated to high pressures, should be contained by a cage guard or other restraining device when being inflated, after being repaired or otherwise removed from the wheel. This includes truck, forklift or earthmoving plant tyres.

If restraints are not available, a suitable system of work is to be used, such as inflating from behind a barrier.

When a tyre has to be inflated while it is still on the vehicle, an exclusion zone should be established during inflation.

Exploding wheels and tyres

Divided wheel, split-rim and locking-rim wheel and tyre assemblies are especially likely to explode if poorly maintained, incorrectly fitted, or if assembled or disassembled while inflated.

The most common faults are:

• over-inflation
• removal of split-rim fastening nuts instead of wheel fastening nuts
• failure to ensure correct seating of split rims or tyre beads
• the use of damaged parts, or replacement parts with lower strength than the original equipment.

Non-original after-market nuts and bolts and other fixings could be inadequate.

The inflation system should be fitted with a device that prevents over inflation.

It is essential to deflate tyres before wheel removal to ensure removing the wrong nuts does not result in a serious or fatal accident.

All off-road vehicles should have a maintenance system in place for rims and wheels in accordance with AS 4457.1 Earth Moving Machinery – Off-the-road wheels, rims and tyres – Maintenance and repair – Wheel assemblies and rim assemblies.

Fires and explosions of tyres in service

The primary cause of tyre fires is the application of heat to the tyre, or development of heat within the tyre structure, which can result in an explosion of the tyre.

Heat can be conducted through the rim base to the bead area of the tyre where a small quantity of rubber can be pyrolyzed. The gases given off in the process can be ignited by the continued application of heat. An explosion could originate from the point of heating, with the flame fronts travelling around the tyre in opposite directions and causing a rupture where they meet.

A temperature rise sufficient to cause problems can be generated by other sources of heat, such as:

• electrical earthing through the tyre as a result of lightning strike or powerline contact
• wheel component heating through misuse of brakes or electric-wheel motor problems
• internal tyre damage as a result of excessive speed, road camber deficiencies and ply separation.

An uninflated tyre may explode in the same manner as an inflated tyre if sufficient heat is applied to it.

Other factors that can increase the likelihood of a fire or explosion include:

• auto-ignition temperatures of different types of bead lubricants and other introduced materials, which can vary Before any material is introduced into the tyre air chamber, its auto-ignition temperature should be checked, and if the figure is lower than that for the tyre liner or bead, it should not be used. Auto-ignition information can be found on a product’s safety data sheet (SDS).
• accidental use of an incorrect inflation medium (such as LPG or other explosive gases) through contaminated air supply or other means.
• carbon dust given off from pyrolysis of the tyre liner, which can auto-ignite at temperatures as low as 200°C, the lowest auto-ignition temperature of any material likely to be encountered in a tyre.
• low flash point fuels and solvents, which can be absorbed by tyre rubber. This can increase the likelihood of a tyre catching fire where a heat source is introduced, increase the seriousness of any fire that does eventuate, or both.

A tyre explosion can occur even where no fire is visible. Smoking tyres or brakes should be treated as a potential tyre explosion and the vehicle isolated accordingly.

Prevention of tyre fires

To prevent tyre fires, you should:

• ensure correct inflation of all tyres and check on a daily basis
• ensure no hot work is undertaken around the wheels and rims
• make sure trucks are not overloaded
• consider installing on-board tyre pressure and temperature sensors. 

Prevention of tyre explosions

To prevent tyre explosions consider implementing these options:

• Nitrogen inflation: nitrogen inflation will significantly reduce tyre explosions.
• Inhibiting agents: consider the use of fire inhibiting agents and fireproof coatings on the inner surface of the tyre.
• Earthing vehicles: consider earthing vehicles against lighting strikes so the tyres do not provide the earthing path. 

Combating tyre fires and potential explosions

If a vehicle catches fire or a heat source is recognised and there is a potential for a tyre explosion, you should immediately establish a prohibited zone of at least 300m around the radius of the vehicle. The prohibited zone should remain in place for at least 24 hours following the removal of the heat source. An emergency crew should remain in attendance during this period.

14.13 Maintenance and repair of roads

Roads and other vehicle operating areas should be regularly maintained so they do not develop bumps, ruts or potholes. These may make control of vehicles difficult or cause health problems due to whole-body vibration. In addition, excess mud and slurry can seriously affect the manoeuvrability and braking potential of the vehicles using the road and other vehicle operating areas. 

Dust suppression

Dust generated by moving vehicles can reduce visibility to dangerous levels and create a health hazard. Dust is typically reduced by applying water to the road surface. In dry conditions, watering helps maintain compaction and surface pavement strength. It also maintains the pavement shape, reduces the loss of gravel, and helps reduce corrugation of the road surface.

The quantity of water needed to control dust depends on the nature of the road surface, traffic intensity, humidity and precipitation. During drier months, a typical road may need one to two litres per square meter per hour. Liquid stabilisers and polymers can also be used, which can help strengthen the surface layer and provide a degree of water proofing.

Where water restrictions are an issue, consider reducing speed limits and constructing the road with an alternative material so the surface is less dust prone.

Waste oil or other hydrocarbons should not be used to supress dust due to environmental concerns and traction issues when wet. 

Safety when watering roads

Watering roads to suppress dust has the potential for vehicle accidents. The water tanker could turn over or the roads could become slippery because of wet bends, downgrades and any other sections of road where brakes may be applied (such as intersections).

Water tanker drivers should avoid driving across gradients due to the potential increase in instability of trucks carrying fluids. As a hazard control, consider installing baffles in tanks carrying fluids to help prevent movement of water inside the tank.

‘Patch’ or ‘spot’ spray roads, and avoid blanket spraying or depositing large amounts of water on the roads (especially in braking areas, gradients and junctions of haul roads). It is recommended water tankers are fitted with systems that can be effectively controlled by the operator to manage water output.

The sequencing of haul trucks following the water cart should be risk assessed to ensure the sprayed water will not cause traction issues for the haul trucks.

Regular inspections of the road surface should be made to ensure that dust is supressed, and adequate traction is maintained.

Procedures for watering roads should detail actions to take when roads have been excessively watered, reducing traction. This is particularly important on haul roads.

Where possible, water tankers should be filled at the lowest point, and dust suppression applied travelling up hill. This will avoid fully loaded water tankers travelling downhill reducing the potential for the loss of vehicle control due to traction loss or brake failure.