What Are Dumpsters?
First, the Dumpstars dumpster, and then below, the history of dumpsters through time. Below, a video of how the Dumpstars dumpster works:
So common is the "dumpster" in modern times, that it is difficult for many of us to imagine what life was like before George Dempster made it a household word. Few other inventions had a more sweeping and positive impact on public health and sanitation practices than his original Dumpster container system, which introduced many communities to a new concept in bulk refuse storage.
So What is a Dumpster?
It may sound like an obvious question, but "dumpsters" come in a range of sizes, uses, and configurations, from tiny one cubic yard plastic bins for food waste, through to enormous forty cubic yard steel bins that can take vast amounts of demolition and construction waste for trash removal.
A dumpster is a large steel waste receptacle designed to be emptied into garbage trucks. The word is a genericized trademark of Dumpster, a American brand name for a type of mobile garbage bin (MGB). Generic usage of dumpster is also common in Australia, although Dumpster is not an established brand there.
The main purpose of a dumpster is to store rubbish until it is emptied by a garbage truck and disposed of. Dumpsters can be used for all kinds of waste, or for recycling purposes. Most dumpsters are emptied weekly by a hired rubbish removal service.
Many businesses, apartment buildings, schools, offices, and industrial sites have one or more dumpsters to store the waste that they generate. Dumpsters are emptied by front-loading garbage trucks. These trucks have large prongs on the front which are aligned and inserted into arms (or slots) on the dumpster. Hydraulics then lift the prongs and the dumpster, eventually flipping the dumpster upside-down and emptying its contents into the truck's hopper (storage compartment).
Dumpsters and Roll Off Containers
Other dumpsters are smaller and are emptied by rear-loading trucks. Mobile construction dumpsters are 6 cubic yard dumpster trailers called Roadrunners, and are commonly used in Dallas, Texas on smaller remodeling jobs or for garage or lawn cleanouts. Roll-off dumpsters are large dumpsters from 10-45 cubic yards. These are used at demolition sites, cleanouts, renovations, construction sites, factories and large businesses. 95 gallon dumpsters (or toters) are used by small businesses and homes where a normal bin would be too small, but a regular dumpster would be too large.
Roll-off / Containers / Dumpsters / Opentop Containers are just a few of the names given to these large capacity receptacles. These containers are normally carried by very large trucks with hydraulic arms which load and unload the containers with ease, thus allowing these trucks to place these containers in a relatively unobtrusive position.
History of the Dumpster
In the early 1930's 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 consisted of a hydraulic hoist mounted to motor truck where open top buckets could be lifted and transported. The device also allowed for emptying of the shallow buckets by tipping, 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 for refuse but sanitation was becoming a critical problem in many cities and refuse packer trucks were gaining popularity by the late 1930's, but refuse storage methods were substandard. Businesses and apartments which generated large concentrations of waste in densely populated areas were particularly problematic and this was further exacerbated by disposable packaging used increasingly used in consumer products which greatly increased the volume of refuse. Rows of overflowing trash cans were not uncommon, and were unsightly in many otherwise modern cities.
With the availability of larger and now fully enclosed containers with hinged emptying, the Dumpster system first began to attract the attention of sanitation officials. In 1937 Dempster's hometown of Knoxville became America's first "Dumpster City", with the purchase of a single Dumpster truck and eighteen containers of two cubic yard capacity. The system cut collection costs by more than half. A single person could now pick up, empty and return each container which were sealed against insects and vermin, and from wind and weather.
Many more "Dumpster Cities" arose, and the term "Dumpster" is now commonly used to describe any large refuse storage container, perhaps due to the fact that the "Dumpster" was a piece of equipment with which the public had extremely intimate contact, for a Dumpster was on the street almost all the time emblazoned with the trademarked name.
An improved model Dumpster was introduced at the end of the decade which featured direct hydraulic ram lifting. Following the war, Dempster saw great promise in the refuse collection body market and promptly introduced the Dumpster Kolector, a ten cubic yard 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, and the same Dumpster hoist could service commercial and residential containers. This "satellite" system would find more widespread use in the 1960's with modern front loaders, and spawned multiple trailers pulled by a single truck.
Dempster's Dumpster system was steadily improved following the war and was the solution to the problem of sanitary refuse storage for many municipal councils. Their only major competitor - Brooks Brothers – produced a Load-Lugger system which was better suited to construction sites and never matched Dempster's broad selection of containers.
A more efficient method of bulk collection was however, already emerging. A fixed-bucket front loader was modified to service detachable containers. It used forks to couple with individual containers, which were dumped into a large open body. These "front loaders" became common as hauling distances increased. Dempster introduced their own front loader, but it was a stop-gap solution.
In 1955, the Dumpmaster front loader line was added to the Dempster range. The original Dumpmaster was a departure from the old Dumpster as it was capable of emptying several containers before going to a disposal point. A special new top loading, top dumping container was also developed, which was designed to be emptied by inversion over the truck body. This front loader was actually an amalgamation of two well established products: The Pak-Mor refuse packer body and the Holmes-Owen bucket loader which had been offered as a variation of the loader since the 1930's.
On approaching the container, the claws were positioned below the protruding studs, and the vehicle advanced until the claws were beneath the studs. A ramp was formed by the claw which helped guide the stud into the eccentric slots as the arms were raised. The main hoist arms elevated the container above the cab, and then the tilt cylinders inverted the container over the opening of the body. The container remained in place by gravity. A riser extension to the circular body helped channel the refuse and minimize wind-blown refuse.
The new system was incompatible with the bottom dumping Dumpsters in which many cities had invested and some cities had encouraged or coerced merchants into Dumpster containers to be serviced by city-owned trucks. Sanitation departments could hardly pull the rug out from such a system.
There was really no way around this, since a front loader designed to service bottom-dump cans would have been needlessly complex. Dempster was in an unenviable position. Their new Dumpmaster was in direct competition with their established Dumpster System. West coast builders were selling the front loader idea to communities that were often still employing manual collection with open body trucks and Dempster was virtually unchallenged in the portable container field and had the eastern market to themselves. The old Dumpster System was not discontinued, and although a completely new style of front loader would emerge, a solution to the compatibility issue was found.
The Dumpmaster was probably the first front loader to use a compaction type body. Though Dempster didn't invent the front loader, the company found success with the next generation of front loaders. Dempster himself would personally contribute in designing two critical features still used on virtually all modern designs to this day.
"The nearest thing to automation in rubbish collection" is how Dempster described the new 1957 Dumpmaster front-loader. Though similar to the 1955 version, this machine was so advanced that it was astonishing how quickly the firm developed it. The new Dumpmaster was the result of a collaboration between George R. Dempster and William Herpich, an engineer. Herpich was responsible for the Hydro E-Z Pack side loader which was one of the first heavy-duty, all hydraulic side loaders on the market, and the 1957 Dumpmaster packer body was based on a similar concept with a top loading bay and full-travel packer panel. The use of this body on a front loader was a more practical application since manual loading height was not a factor. The reinforced body supported packing pressures of 58,000 pounds, more than double that of the old mechanical Pak-Mor body.
If this were not impressive enough, Dempster and Herpich redesigned the lift mechanism and container coupling, creating a new industry standard. Like previous front loaders, the lift arm pivot axis was near the lower front section of the body, just behind the cab. But instead of straight, horizontally inclined arms as before, the new arm rose vertically to a point above the vehicle cab and then curved forward and dropped just ahead of the font bumper. This "curved arm" completely cleared the vehicle door area during all phases of the loading cycle, eliminating a major safety hazard to the driver. It was perhaps the single greatest advance in front loader technology and has been imitated ever since.
The third change on the new Dumpmaster was in the container coupling and dumping method. Instead of the claw and stud method, coupling was now achieved with a set of forks. Fork coupling had already become the standard of west coast front loaders, which predominantly used a set of flat forks engaging slots in the bottom of the container. Dempster's new models set the forks on edge and moved them to the outboard ends of the loading arm assembly to engage shallow pockets welded to the sides of each container. These "side forks" gave the driver a much better view of the coupling during hook-up and the side pocket slots were also less hazardous to pedestrians.
Those who still preferred the old Dumpster System, and used it with transfer trailers could now order a Dempster-built compaction trailer. Coupled with a GRD hoist on a short wheelbase truck, it added up to an efficient satellite system. Added to this was the new roll-off system, and by decade's end Dempster was the undisputed leader in detachable container refuse storage and disposal systems.
By addressing problems associated with commercial and bulk waste disposal and employing innovative solutions, Dempster grew into an industry powerhouse, and dumpsters have advantages over regular junk disposal services.
With innovate products appearing across the country, the Dempster name became synonymous with refuse containers.
Short runs to the disposal site soon became a thing of the past for many communities as dumps filled up, land prices soared and public opposition to sanitary landfill methods became acute. The "short haul" Dumpster system was costly and time consuming when longer runs became necessary and new front loading container system proved more versatile. In 1961, Dempster offered conversion kits for the old Dumpster containers, allowing cities who had already invested in Dumpster System equipment to convert to front loader service. The kit required removal of the top of the box over which a top dumping door assembly was welded, as well as a pair of side fork pockets.
To service the converted containers, some up to twelve cubic yards capacity, a new heavy duty Super Dumpmaster was available with a 30 cubic yard body and a packer blade delivering a force of 85,000 pounds against the load. A ten cubic yard container may not seem unusual in commercial collections today, but some fleets consisted of open body of the same capacity. A high-capacity Super Dumpmaster and one operator could replace a small fleet of trucks and several crew.
Dempster refuse systems became increasingly popular during the 1960's, as contractors and municipalities realized the benefits on containerized refuse. The new decade brought new additions to the Dinosaur roll off family, most notably the DinoPacker stationary compaction unit.
In late 1961, another major engineering change to the Dumpmaster loading arm mechanism was revealed. The common practice was to actuate the lift arms with set of hydraulic cylinders mounted under the front of the truck body and parallel to the chassis. Dempster's new design featured long stroke cylinders, with the piston end mounted to the outside of the truck body and the rod end coupled directly to each lift arm. By acting directly on each lift arm, working pressures could be lowered leading to less heat in the hydraulic system. Ever higher lift capacities were possible.
Though the Dinosaur was the most recent of the Dempster products it quickly became the most versatile, with a bewildering array of configurations and uses. The Dinosaur may be categorized as a "roll-off", but was actually a type of sliding hook lift hoist. Like a standard roll-off, the Dinosaur featured a tilting frame, but whereas roll-offs use a hoist and cable to load, the Dinosaur's hoist coupled directly on the container through a spring-loaded bail.
The advantage to the Dempster system is that it was truly double acting, capable of "pushing" a container on to a dock at frame level without the aid of gravity. Cable type roll-offs rely in large part on the weight of the container.
The Dinosaur had uses beyond refuse removal. Pulpwood, scrap metal, factory machinery, and liquid container vessels were among the non-refuse applications and with a flat bed it became a heavy duty equipment hauler. Stacked, tandem and split-compartment containers could be specified and a semi-trailer version, the Dinotrailer was also offered. Off-highway models rated at 80,000 pounds gross were available.
The standard open-top box, in capacities of up to 40 cubic yards was to eventually become a staple of demolition and construction industry. For refuse handling, Dempster offered similar closed boxes as well as the Dinopacker, a stationary packer with a short stroke "half pack" blade. Initially built in sizes up to 28 cubic yards, it featured an independent power supply, allowing it to be left on site indefinitely. A Dinosaur hoist truck would haul it away when full, leaving an empty unit to replace it if necessary
Rounding out the lineup was the Dinomaster, a detachable version of the Dumpmaster front loader. With this option, one truck could now service large roll-off containers, stationary packer containers and front loader routes with a single motor truck.
The Dinosaur was a well chosen name. Detachable bodies and containers were not new technology, but few manufacturers had ever offered them in the sizes Dempster was building, not to mention the wide variety of styles. The firm was becoming the "one stop shop" for bulk and material handling needs, even offering consulting and site engineering services.
George Dempster died of a heart attack at the age of 77.