Classic Refuse Trucks DEMPSTER

Beginnings: The Dempster Dumpster

George Roby Dempster* was born in 1887 to Scottish & Irish immigrants. By age sixteen he had a job running a locomotive (while not in school), having previously worked various railroad jobs in Virgina. As a young adult, Dempster later worked as an equipment operator on the Panama Canal project, and in the early 1930's he formed a construction company with his brothers back home in Knoxville. It was during this time that Dempster developed a novel device for the lifting and transporting of portable storage containers which would be of great significance not only to the refuse collection industry, but to the betterment of sanitation practices in general.

The first Dempster Dumpster lifts were employed by the family company on their construction sites, and consisted of a hydraulic reeving hoist mounted to motor truck whereby open top buckets could be engaged, lifted and transported. The device also allowed for emptying of the shallow buckets by simply tipping them as they were held in the raised position by the hoist. First patented in February 1935, the device began to attract the attention of rival operators and before long Dempster Brothers Incorporated was in the truck equipment business.

Though Dempster probably didn't originally envision his invention as refuse collector, it turned out to be a perfectly timed solution to what was becoming a critical sanitation problem in many cities. On the collection front, refuse packer trucks were first beginning to gain favor by the late 1930's, but refuse storage methods left much to be desired. Particularly troublesome were businesses and apartments, which generated large concentrations of waste in densely populated areas. This was further exacerbated by a trend toward disposable packaging used by all manner of consumer products, which greatly increased the volume of refuse. Rows of overflowing trash cans were not an uncommon eyesore, a blight on many otherwise modern cities. Another method, was the refuse vault, which had to be shoveled out by the collectors, was not only unsanitary but a tedious waste of manpower.

The Dumpster System: At left, container is raised by lifting against pins welded on each side of bin, power provided by a hydraulic reeving hoist. At right, once in the raised position, an arrester hook suspends top section of container while hoist is lowered allowing bottom-hinged dump door to open.

With the availability of larger and now fully enclosed containers with hinged bottom dumping, the Dumpster system first began to attract the attention of sanitation officials. Not surprisingly, it was Dempster's hometown of Knoxville that became America's first "Dumpster City" in 1937, with the purchase of a single Dumpster truck and eighteen containers of two cubic yard capacity each. Not only did the system generate favorable public response, the city also cut collection costs by more than half compared to the old method of open dump trucks. One driver could now pick up, empty and return each container without the need for any additional men. The containers sealed out insects and vermin, and sealed in refuse from wind and weather. This method is termed the "short haul" system. Because small capacity containers are used, it was practical for situations where the disposal point was relatively close to the collection area. At this time, many American municipalities still had dumps located within or near the city limits.

There would be many more "Dumpster Cities" in the future. Though it did not happen overnight, the Dempster Dumpster changed refuse handling practice on such a scale that to this day, the term "Dumpster" is commonly used to describe any large refuse storage container, a brand recognition factor that would be the envy of any company. Perhaps this is due to the fact that the "Dumpster" was a piece of equipment that the public had extremely intimate contact with. For example, a Gar Wood Load-Packer might pass briefly by your house two days a week, but a Dumpster was on the street almost all the time, emblazoned with the trademarked name for every user to see.

Left: Dumpster system found many uses, like this 1939 model that hauled screenings and de-watered sludge from a sewage treatment plant. This is an improved second generation model which used hydraulic rams acting directly on lift arms, simplifying the mechanism and increasing lift capacity for ever larger containers. Right: The 1945 Dumpster Kolector trailer pre-dates the "train system" by a good fifteen years.

An improved model Dumpster was introduced at the end of the decade which featured direct hydraulic ram lifting via pivot arms and chains. The new hoist not only eliminated the cables and pulleys of the old reeving hoist, but also boosted the dead lift capacity to handle bigger containers. Production continued during World War II, with Dempster supplying units to the armed forces as well as other necessary war material. Following the war, Dempster obviously saw great promise in the refuse collection body market and promptly introduced the Dumpster Kolector, a massive ten cubic yard end-dumping container fitted with a single axle. It was designed to be towed behind a light truck, and when filled was merely hauled away by a Dumpster hoist truck which could also deliver an empty unit. This system eliminated down time for the crew, and the same Dumpster hoist could service commercial/apartment containers throughout the route. This "satellite" system would find more widespread use in the 1960's with modern front loaders, and spawned "trains" of multiple trailers pulled by a single truck.

A 1945 model LFW hoist lifts, hauls and then empties a loaded Dumpster Kolector trailer.

* A detailed biography by J.C. Tumblin is available online here: GEORGE DEMPSTER BIO

1/7/06