Neal Bolton

By Neal Bolton

When we hear about a fire occurring at a solid waste facility, we often think of a hot load, a dropped cigarette, the methane gas system, or spontaneous combustion originating in a large pile of green waste. Less often do we think of fires originating in our machines. And why should we? Those are our machines, they’re on our side, and they’re supposed to be used to fight fires … not cause them.

But a recent survey of several landfills from around the country shows that machine fires are not all that uncommon.

What causes machine fires? Well, that’s sort of a trick question. The cause of a fire, often referred to as the “source of ignition,” can include

• a spark from machine hitting a rock or piece of metal;
• a spark from a poorly functioning exhaust system;
• an electrical short;
• arson;
• lightning;
• poor housekeeping; and
• flammable liquid.

Most machines have these potential sources of ignition present. Most landfills and many transfer stations have had one or more machine fires. That fact is probably not too surprising when we consider that machines move large quantities of trash, generate heat when operating and utilize flammable liquids like diesel or gasoline, hydraulic fluid, oil, and grease.

Perhaps the more revealing question is: Once machine fires start, why do they keep burning?

Think of it this way. Suppose we found that a large percentage of forest fires began with a lit match. At first glance, those lit matches look like a big problem, huh?

But when we consider the billions of matches that are lit each year, it turns out that very few result in forest fires. That’s because making the jump from a lit match to a forest fire requires one important step—there must be fuel to burn.

My youngest son and I recently went to the mountains fishing for five days. We obtained a campfire permit from the local forestry office. The fire permit listed rules for keeping our campfire safe. These included clearing all flammable material from around the fire area and keeping a shovel, ax, and bucket of water close at hand so that if the fire attempted to spread, we could quickly put it out.

The forest ranger who issued the fire permit knew that fires are hot. He knew that our fire could be a potential source of ignition. But his focus was on prevention and containment.

It’s the same way with machine fires. Many machines create sparks when moving material. The exhaust system of every machine is hot enough to start a fire. Other sources of ignition sometimes occur. But the real factor in determining whether a machine makes sparks—or burns to the ground—is most often related to housekeeping.

If you want to prevent machine fires at your facility, take a lesson from a forest ranger.

Remove All Flammable Material
In regard to your machine, this means keep it clean. Prevent the buildup of oil, grease, and fuel by periodically pressure-washing or steam-cleaning the machine. Be sure to clean the entire machine---in, under, and around.

On a daily basis, inspect the machine for accumulated trash. Look wherever trash could accumulate, such as the engine compartment, articulation joint, undercarriage, wheels, etc.

These two things—oily buildup and trash—represent the most common “fuel” that causes serious machine fires. A clean machine is less likely to catch fire and much less likely to continue burning than is a dirty, trash-packed machine.

Provide the Means to Put it Out
Because even a clean machine can catch fire, it’s vital that all machines be equipped with functional fire extinguishers. The fire extinguisher is intended to put out small fires or provide a safe exit for the operator in the event of a large fire.

Many machine owners install automatic fire suppression systems on their machines. These systems include a network of temperature sensors and a parallel network of spray nozzles. If the sensors “sense” the presence of a fire on the machine, the nozzles spray fire retardant into the engine compartment and/or other areas where a fire is likely to start. Again, if the machine is clean, these fire suppression systems work very well. If you are considering installing a system like this, be sure it is designed and installed by a reputable company. Also be sure to inspect it as suggested by the manufacturer.

Finally, after you’ve committed to keeping your machines clean and have provided some means of extinguishing a fire, you must train your crew so that they know how to prevent machine fires and how to respond if one occurs.

Most machine fires can be prevented. Do your part by keeping your machines clean and fire safe.

MSW - September/October 2005