Classic Refuse Trucks FRONT LOADERS

FRONT LOADER DEVELOPMENT

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Since front loader technology was in its infancy, no "standard" existed in 1955 for detachable front load containers, and several different methods for coupling truck and container emerged. Since rights to patented methods would be costly, it was in each competing manufacturers best interest to design their own unique method, and try to sell the customers on that particular system. One very interesting design (which unfortunately has defied identification) is pictured at left and utilized a set of straight arms and a self locking coupler that engaged rearward canted slots on the sides of the container. Another interesting feature of this truck is what appears to be a modern compaction body with a bi-folding charge door.

The picture at left is a blow-up from a January, 1956 advertisement for White Trucks, which dates it as 1955 or older. This photo has been featured previously here at CRT, and there have been some very good guesses as to its identity. However, as of this writing nothing definitive is yet known about it. I consider it the potential "missing link" between Bowles' front loader and everything that followed in its wake. Anyone who can identify and/or provide any information about it is encouraged to contact CRT.

Editors Note: The packer shown above has now been identified as the Nu-Way Sanitary Pack-Van built by Towner Manufacturing of Santa Ana, California.

For more information, see the Winter 2008 News Update here at CRT

Dempster, the brand most associated with detachable containers, officially entered the fray with the 1955 introduction of their Dumpmaster system. As it turns out, this first Dempster front loader was not even their own design. It was in fact a rather ingenious adaptation of the Holmes-Owen Truck Loader, bolted on to a Pak-Mor I-series side load packer body. Heavily modified for use with portable containers, it was patented by the Holmes Company, and replaced the fixed bucket of the truck loader with a crab-like claw that engaged shafts projecting from the sides of the container. Double-cut slots automatically held the container in place as it was inverted during the dumping cycle.

1955 Dempster Dumpmaster system was a modification of the Holmes-owen Truck Loader and fed a Pak-Mor body adapted for top loading. This short-lived model was Dempster's first front loader

The Dumpmaster was very likely a stop-gap design, intended to win Dempster a toehold in the front loader field, but would not last long. Fortunately, their designers would shortly come up with a brilliant idea which would become a staple feature of the industry to this day. The first Dumpmaster is noteworthy in that the firm was the first major manufacturer to field a front loader with a compaction body, albeit one made by Pak-Mor. Though Dempster would soon be making their own packer body, they would later collaborate with Pak-Mor, teaming a model GRD high lift Dumpster which fed their bottom dumping containers into a square-bodied 32 yard Pak-Mor transfer trailer. The Dumpmaster also marks a divergence of thought in front loader design; the "eastern" school of design, led by Dempster (and later E-Z Pack) would emphasize heavy, full compaction bodies while the "western" contingent, led by Bowles (and later Bemars) would be defined by lightweight half-pack models, more suitable for the stricter weight regulations on that coast.

Meanwhile, back in Los Angeles, another small company called Cook Brothers brought out their own truck which may have become a mere footnote in refuse history, except for one little "twist". With an open body very similar to Bowles' loader, the Cook Brothers loader differed in that it used conventional straight lift arms, connected at their leading edges by a "rock shaft" to which the forks were attached. Once the container had been hoisted over the body, twin hydraulic cylinders twisted the rock shaft to invert and dump the container. As an additional benefit, the forks could now be twisted to gain a level approach to containers above street level, such as on loading docks. Though Cook Brothers were never a major player, this feature (the brainchild of Henry Harbers, of Pasadena) was a critical development, and has since been a feature of virtually every front loader ever built.

In 1957, Bowles unveiled their answer to the Dumpmaster in the form of of a "Load-Packing" front loader. The new design, now mostly enclosed, used a standard type compacting platen, moving from front to back, which was supported by rollers on its lower edge and by a set roller trolleys on each side. A set of of single acting hydraulic rams pulled the platen rearward only far enough to clear the refuse in the area just below the upper opening. As refuse accumulated in the rear of the body, the blade began to compact the load. It was the first "half-pack" front loader, soon to be a defining feature of the west coast style. As a small manufacturer, Bowles likely came up with this design to cut cost and simplify construction. But the single acting cylinders also gave the new loader somewhat more "punch" than the common mechanical packers of that day, such as the MB Packer (cable driven) and Pak-Mor (chain driven). Compaction stress was also more evenly distributed, allowing for lighter body bracing and reduced weight. Even as long-stroking multiple stage telescopic rams became common, this new half-pack system would remain popular due to its weight savings and fast cycle time. Initially popular in the west, this system would again find much wider favor as weight savings became a more important issue nationwide.

Revolutionary 1957 Bowles Half-Pack system showing packer plate (A) guided by roller trolly (pink highlights) in sidewalls of hopper area. Actuating rams had cylinder end (B) mounted inside the storage body, while rod end worked outside the narrower hopper walls, connected to the blade through the roller track slots. Both rods and slots were protected by a sheetmetal cover. Packer plate at full rearward position (C) would just clear hopper area, and affected compaction only as body became full. Packer also assisted in discharging load as body was hoisted.

It had been five short years since the original Bowles front loader, but this newest version was almost unrecognizeable by comparison. They were the state of the art in the west, and in addition to the features mentioned previously, the new models wore an improved lift arm, curved slightly to clear the front wheels to allow steering control while grabbing a container. The new loader also added a Harbers-type rock shaft fork carriage. Bowles and Gentile had now almost singlehandedly invented the front loader, and darned-near perfected it. His front loaders dominated the southern California market for years, and saw increasing sales throughout the region. But the firm was not well known back east, where big things were also happening at Dempster.

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11/6/05