When it comes to using soil and asphalt ride-on compactors, manufacturers play a supporting role with the operator in keeping everyone on the jobsite safe. With each new model, it seems like more dedicated safety features are being incorporated into the machines.
It's no longer an anomaly to have ROPS/FOPS and seatbelts as options or, in some cases, standard equipment. "Sakai? includes ROPS and seatbelts as standard equipment on all roller models delivered in North America," says Dave Brown, vice president sales and marketing, Sakai America. "That's how important we believe these normally optional accessories are to operator safety."
Backup alarms and horns make it easy for operators to alert workers on the ground and in the surrounding areas to any equipment that might be moving in their direction.
And there are several systems available to control movement during an emergency situation or equipment failure, or simply when starting/stopping the unit. Emergency stop buttons - located within close proximity to the operator - allow the machine to be shut down in an emergency by simply pressing a button.
There are also brake systems that automatically stop movement in the event of hydraulic system or engine failure. According to Brown, Sakai rollers include three different braking systems: hydrostatic service brakes, SAHR brakes and combined automotive-type foot brakes.
All new Bomag models also feature SAHR, or failsafe, brakes that are within both the travel motors and axles, says Dave Dennison, product manager, Bomag. "If you lose hydraulic pressure or engine function for any reason, these brakes have internal springs that allow the component itself to apply its brakes automatically," he explains.
In addition to SAHR brakes, Dynapac rollers are equipped with relay switches and interlock systems to prevent unintentional and/or unexpected vehicle movement when stopping/starting the machine. One such relay switch requires the operator to move the control into neutral to release the brakes. This prevents the machine from moving as the brakes are released, notes Nono Bauleth, service manager.
The same basic principle applies to the interlock system, where the engine shuts off within four seconds if the operator releases the brakes and stands up. "It doesn't allow the machine to move without the operator," says Bauleth.
Visibility and ergonomic features
Some of the newer features found on ride-on compactors benefit safety indirectly. For example, in models with cabs, tinted glass may be used to reduce glare and help maintain visibility around the machine.
Some asphalt rollers incorporate swivel seats that turn 90° or more. "Operators have a clear view in front and behind the machine," says Dennison. "For large, highway-class [asphalt] rollers doing road production work, they're pretty much standard. They can help reduce operator fatigue and ease operation, because he can turn sideways compared to turning all the way around. Also, by moving the seat to the furthest position left or right, he has a good view to the edge of the drum, as well as the front and rear.
"Good general visibility from the operator's platform is a must to be able to identify potentially dangerous situations," he adds.
Ergonomically designed control layouts improve not only safety., but also performance. "With good ergonomics and proper layout of the cab, you reduce fatigue. [You] give operators the ability to operate comfortably for a longer period of time, so they're more productive," says Dennison. "With good placement of controls, instrument panels, steering wheels, levers, etc., it's a lot simpler operation as well, so operators don't need to reach up, over or down. The more controls you can put in the 'cockpit', the more you can improve productivity."
Many manufacturers have made entry into the machine safer by addressing step height and position, as well as adding grab handles, safety railings, etc. Beyond the steps, features such as anti-skid plates and materials on the operator platform floor keep the operator from slipping once seated in the unit.