Rolloff containers and trucks are swapped out when the grapple has filled one container to capacity.
Grapple Truck Features
There are enumerable factors to consider when specifying a grapple truck: What chassis do I want? What lighting is required? If my grapple truck has a body, how should it be specified? Many of these decisions are similar to ones you make for other equipment, however, more unique to grapple trucks are choices like control types, outriggers, boom swing devices, and some safety features. Decisions regarding these elements can greatly impact the functionality, maintainability, and safety of your grapple truck.Outriggers
Whichever style of outrigger you specify, a good outrigger should always have a generously sized pad, to spread out weight over a larger surface area. Small outrigger pads leave all the weight concentrated in a small area, which can cause them to bust through thin concrete, to sink, or to scar asphalt. Another important factor in the effectiveness of outriggers is the spread. The farther out the outriggers can reach, the more stability they give. There are three basic types:
Boom swing drive
- Out and down: these can be placed on nearly any surface, and they can be adjusted to accommodate curbs or traffic.
- A-frame: these tie into the pedestal assembly and put minimal stress on the truck frame; however, they cannot be adjusted for curbs or potholes.
- Fold down: these offer the advantage of a wide span, but they can't be adjusted and may even pose a hazard due to the fold-down motion.
There are two standard methods to drive boom swing:
- Rotary actuator: a direct-drive hydraulic motor and gear. Advantages include no gear reduction and easy maintenance; however, exposed hoses and valve banks are vulnerable to damage. When specifying, consider adding hose sleeves and bank guards at the operator station.
- Slewing ring: a large gear turned by a motor mounted on the side. Hoses can be protected by running through the center of the pedestal assembly, but this makes the parts difficult to reach for adjustment and maintenance. Yet the bolts require frequent retorquing, a labor-intensive procedure.
As with all equipment, you should make sure the manufacturer provides you with training manuals and videos. To prevent leak down, or collapse in case of hose rupture, all load-holding cylinders must include safety locking valves—either counterbalance valves or pilot-operated check valves. Another beneficial safety feature is a boom-up warning alarm to alert the operator when the boom is over the safe travel height for driving.Safety Standards And Regulations
Until May there had been no industry standard directly addressing grapple trucks used for refuse collection. The new ANSI Z245.1 standard released by the Waste Equipment Technology Association (WASTEC) for mobile waste collection equipment now includes grapple trucks. Although this standard does not yet address the important factors of metal wear and fatigue, it does cover basic stability requirements, walk-through type controls, and conspicuity, all important factors in making your grapple truck safer. For other considerations regarding the functionality, maintainability, and longevity of equipment, the most reliable guide remains the experience and word-of-mouth recommendation your fellow professionals in the industry.
— Blair Petersen is marketing manager with grapple manufacturer Petersen Industries of Lake Wales, Fla.
To see a comparison of Grapple Truck functions, click here.