INNOV8 TMAs test to the Australian standard and other standards such as the NHVR and MASH.
PERFORMANCE, MAINTENANCE
AND COMPLIANCE AS THE ONLY ROAD VEHICLE DESIGNED TO BE CRASHED INTO, IT IS IMPORTANT TMAS RECEIVE REGULAR MAINTENANCE TO HELP IN PROVIDING SAFETY TO VULNERABLE ROAD USERS. TIM EATO FROM INNOV8 EQUIPMENT DISCUSSES THE IMPORTANCE OF TMA MAINTENANCE REQUIREMENTS.
T
he National Heavy Vehicle Regulator (NHVR) recognises the use of Truck Mounted Attenuators (TMAs), in the road construction and maintenance sector, is now a regular part of ensuring the safety of vulnerable road workers. To keep traffic flowing during maintenance and other roadworks, it is important for asset owners to keep as much of the road open as possible. However, traffic flowing in close proximity to workers presents safety risks. These are commonly reduced with safety features such as cones, lower speed limits, TMAs and sometimes physical barriers. As TMAs act as the last line of defence between a car and a road worker, in many cases they are placed at the front of a worksite in the way of oncoming traffic. In the event a TMA is hit, while the attenuator catches the oncoming vehicle, the brakes and tyres on the truck stop the oncoming vehicle from progressing too far into the worksite. It’s for this reason that Tim Eato, Innov8 Equipment Business and Compliance Manager, believes brakes require regular 36
ROADS MAY 2020
maintenance as he says they are the most important feature of a TMA. His belief is they should be tested beyond the registration stage, recommending tests every three months thereafter. As many TMAs use a compressed air braking system, not conducting regular maintenance of this system could increase the risk of brake failure. “Without regular maintenance and checks to the compressed air system, the risk of brake failure is imminent. Our TMA’s have a regular maintenance check at heavy vehicle inspection stations every three months. As we hire out our vehicles it is important to ensure they are performing safely,” Mr. Eato says. Hand in hand with the brakes, tyres play an important part in ensuring the truck’s roll ahead distance is safe for workers. It is for this reason Innov8 implements periodic inspections of both brakes and tyres instead of a kilometre-based service. The NHVR Standards Guide (VSG-12) states that when designing the installation for a TMA, it is important to take into account the position of the attenuator unit
on the vehicle. This ensures when the unit is deployed, in any position, the minimum front axle load is suitable to allow effective steering and braking. The NHVR guide cites the Performance Based Standards (PBS) steer tyre friction demand standard as a reference for suitable steer axel loading. To ensure road worker and vulnerable road users are protected and the TMA is compliant with Australian standards, INNOV8 Equipment’s Blade TMA comes standard with weight distribution. Mr. Eato says this is a crucial factor for safety. Moreover, if the weight distribution between the front and back axel on the TMA is too large, when the TMA is hit, it may force one end of the vehicle up into the air, compromising the vehicle’s safety benefits. Another important obligation to be considered for the operation of TMAs is the disengagement of the automatic brake system. Stationary TMA’s have an automatic brake system that activates in the event that another vehicle crashes into the attenuator. The NHVR G6 checklist, when certifying
