Fire Safety

No one likes a pile of burning garbage. That burning pile is even more despised when it's still in the garbage truck. The smoldering heap is downright hated when it is accidently unloaded at a landfill, where it can mix with brush and paper while being fueled by methane, a highly flammable byproduct of landfills. Landfill fires can emit dangerous gases and are difficult to extinguish. They're also a public relations nightmare. Stopping a vehicle fire in these situations not only prevents a loss of the machine, but in many situations can save lives and the surrounding property, as well.

Better maintenance practices and equipment design can help lessen the chances of a machinery fire, but accidents still happen. A couple of guys near St. Louis discovered that in late April when the contents of a garbage bin they were dumping in the back of their truck exploded. Some illegal chemist had set up or discarded a meth lab in the bin. The operators were slightly injured, but the implications of the event has had far-reaching effects. Local garbage companies vowed to have their employees take a meth lab awareness program so they'll know how to spot the danger before it's too late. www.hypertherm.com.

On a garbage truck, there are two significant opportunities for fire, either on the chassis of the truck itself, or in the case of the meth lab, in the garbage that is picked up and then transferred to the compactor. The most common cause is the latter, typically when backyard chefs dispose of smoldering coals.

"A burning load is a tough thing to deal with," says Bob Oudenhoven, product manager, Leach Co., Appleton, WI . "When the truck body is full of dry garbage, there is a lot of flammable debris with considerable stored energy."

The second type of garbage truck fire often boils down to poor house keeping. Front-loading trucks are built on cab-over engine chassis where the engine extends out of the rear of the cab. Windblown trash can drift back there and land on the hot turbocharger or exhaust manifold, where a fire can occur. The situation is further complicated by spilled fluids or accumulated grease, so proper maintenance practices are essential.

This is an area where a hand-held fire extinguisher (80% of the Leach trucks leave the factory so equipped) or an on-board fire suppression system would make a difference. "Generally a fire of that type doesn't have a lot of mass," says Oudenhoven, and "can be handled with fire extinguishers." A mounted system works well, too. On Leach's trucks these systems are mounted on the forward part of the chassis with two or three discharge ports that flood the back of the engine and cab.

Installing a fire suppression system in the truck body is generally not feasible. The compacted garbage is very dense, and the environment does not provide a good location for nozzles to dispense liquid or dry chemicals. For some haulers, when a fire is discovered in the truck body, the procedure is to find an empty parking lot, dump the load as fast as possible, and call 911. This usually results in a hazardous waste clean-up fee, but if the load is not dumped, the fire can travel through the truck, where fuel and hydraulic fluid will add to the fire.

On Leach's equipment central fire suppression systems are not factory installed, which is typical across the industry. The pressurized systems generally require a certified technician.

At the landfill

Once at the landfill, the danger of a fire starting and the damage that could ensue doesn't subside. For BOMAG's line of refuse compactors, central fire suppression systems are a customer request item that gets installed on at least 80% of its products.

There are plenty of dangers at the landfill, from blowing debris to spontaneous combustion of the decaying garbage. But maintenance is a major factor in preventing a fire on any machine. "If there's been a judgement error when they were adding oil to the engine or the hydraulic reservoir, anything that could be combustible could ignite just from underhood temperatures," says Steve Wilson, product manager, BOMAG Americas, Inc., Kewanee, IL .