There is no question the rear loader compactor is the most recognizable garbage truck. When we picture a garbage truck in our minds, it is this truck we visualize. However have you ever thought how the rear loader began?
Garwood Industries revolutionized the sanitation industry by introducing the first real compacting truck, the Load Packer in 1938. As you can see from the diagram, the basic concept looks familiar. The ability to compact collected trash while on route meant a truck could carry a payload about twice as large. Since this meant fewer trips to the dump, larger municipalities and independent contractors began to favor it during the economic expansion after the war. Detroit was likely the first city to use the Load Packer as that was the closest urban center to Garwood Instrustries. Certainly by the 50s rear loaders were a common sight, and by then other manufacturers were getting in on the action.
Hydraulic cylinders are what makes the compaction mechanism a practical reality. The cylinders operate the packing panels of the compactor. How they operate varies from model to model but the basic concept is the same. The compacting mechanism scoops out trash loaded into the rear hopper and pushes it into the body of the truck. As more trash gets pushed into the body, it gets compacted. The compactor also keeps the truck body a sealed unit - no trash should escape while the truck is going down the street. And since the hopper is at or below waist level, it is easier for workers to load the truck. The compactor does most of the work. When it comes time to dump, another set of hydraulic cylinders lift up the tailgate containing the compactor mechanism. The truck can then be emptied as a conventional dump truck by tilting the body up.
Because there are so many manufacturers of rear loaders, both yesterday and today, this section is best organized thusly:
Heavier duty models of this type of truck evolved by the late 50s and 60s, which could handle commercial and industrial waste. No doubt we have all seen such a truck effortlessly crunch down and swallow a discarded sofa or refrigerator. These newer models featured an ejection panel which served two purposes. The load could be pushed out horizontally through the rear, without having to tilt the body up like a dump truck. The ejection panel provided another squeeze on the load, adding at least 25% to the compaction ratio.
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Page created Jan 5, 2003
Page updated April 14, 2003
All photos from literature of the respective manufacturers.