Classic Refuse Trucks LOAD-MASTER

Roto-Pac and Load-Master: A History of the City Tank Corporation
By Eric Voytko

1964 Load-Master LM-100

Above: 1964 Loadmaster LM-120 (20 cubic yard) refuse packer

    Perhaps more than any other refuse body manufacturer, City Tank Corporation (division of Hagen Industries) was in dire need of a completely revised product in the early 1960s. They had moved from their longtime home in Corona, Queens (New York) in 1961 to a location some three hundred miles south in rural Culpeper, Virginia. Their refuse truck body at the time was the Roto-Pac, an escalator-type loader that had been in production since 1950 and was still finding more than a few municipal customers, most notably the cities of New York, Philadelphia Chicago. But significant advances in the design of rear loading refuse packers were taking place that could not be ignored.

    The biggest industry bombshell was the phenomenal Leach 2-R Packmaster, which introduced the world to the two-panel 'slide-sweep' concept in 1959 and was breaking compaction barriers. Additionally, the 2-R possessed a then unheard of crushing ability, virtually eliminating the need for separate bulk pick-ups. Another major advance in rear load refuse truck technology was Heil Company's revolutionary Duo-Press compaction/ejection system for their Colectomatic Mark II introduced in 1960. It must have been eminently clear to City Tank that the primitive Roto-Pac, with its chain flights and limited hopper capacity would never carry the company through the decade ahead.

    Against this background, City Tank began testing of various components for an all-new refuse packer in 1961, and a prototype unit was operational by late 1962 and sent out on the road for real-world testing. In a later press release, company president John G. Hagan remarked on the impressive performance of the new unit:

"...We made available a prototype unit to a large eastern city, and asked the sanitation department to give it the most severe usage possible. We literally asked them to tear this test unit apart. We put it on the toughest collection routes, and ran it practically on a continuous basis for several months. There were no large or small malfunctions of the unit. With only normal maintenance, the Load-Master exceeded the strict engineering performance that had been predicted. Our experience indicates that this unit out-performed, out-packed and out-worked any batch packer we have used"

The new Load-Master was officially announced in January 1964, as a stable-mate to the existing Roto-Pac series. Load-Master was available in 16, 18, 20 or 25 cubic yard capacity. The model series was LM-100, with the last two digits denoting the body capacity. For example, the eighteen cubic yard version would be designated model LM-118. The packer utilized the basic two-panel, slide-sweep design pioneered by Leach, but with some significant differences. The most visible difference was in the long-stroke (48") slide cylinders, mounted externally on the sidewalls of the tailgate, and within the same plane as the panel. The slide panel (called the 'carriage' by Load-Master) was coupled to the cylinders through slots in the sides of the tailgate. Four steel roller wheels, riding on heavy steel tracks within each slot supported the sweep panel.

But it is the sweep panel that truly set the Load-Master apart from the 2-R. Whereas Leach used a flat sweep panel hinged to the slide panel, the Load-Master was L-shaped, with the hinged end effectively forming an extension of the slide panel. As a result, the sweep panel had a much shorter operating arc (90 degrees) between the fully closed and fully open positions, enabling the use of shorter sweep panel cylinders (16" stroke) and decreasing cycle time. In the drawing below, note also the lower edge of the sweep panel tends to arc upward and over the load as it opens (from positions 4 through 1) thus minimizing the pushing of loaded refuse backwards and on to the street. This effectively increased the useable hopper capacity, and positioned the sweep panel high over top of the load as the slide panel descended during the second phase of the packing cycle. The drawing below better illustrates the features of the Load-Master packer mechanism:

THE LOAD-MASTER PACKER IN ACTION

This video will illustrate how the LM-100 packer operates. Although the truck shown is an early-1980's model LM-120, the packer mechanism is identical to the original 1964 model.

Special thanks to the City of Kingston, New York, Department of Public Works, and to tracksidegorilla for providing video of this classic.

    Load-Master matched the 2-R with a rated hopper capacity of two cubic yards (both models were up-rated in later years to three cubic yards), becoming the first true competitor for the powerful Leach packer. In addition to all manner of residential bulk waste, the Load-Master was capable of handling hard lumber up to 8" x 12' in tests, though this practice was not recommended. A single lever linked to a master control valve in the top of the tailgate controlled the fully automatic packing cycle. The cycle could be manually stopped or reversed at any time.

    For unloading the LM-100, the tailgate was raised by single acting lift cylinders, concealed within the structure. It featured a full-travel, manually operated inclined ejector plate, powered by a telescopic ram mounted horizontally in the body. A protrusion in the bottom of the ejector plate housed the big end of the ram. Load-Master recommended leaving the ejector fully forward in the body (towards the vehicle cab) during normal loading procedures. Once the body became filled, a procedure was recommended whereby the panel was periodically extended and retracted to crush the load within the body, thus increasing the compaction density. This procedure (sometimes called "back-packing") was to be done only two or three times per truckload.

    In spite of Load-Masters recommendations, in actual practice many operators started their routes with the ejector farther back in the body. As the body filled, and the packer began to labor, the operator would then move the ejector forward incrementally to make more room, along with periodic back-packing cycles. This procedure somewhat mimicked the automatic action of the aforementioned Duo-Press system from Heil. Load-Master literature officially discouraged this practice, indicating it could result in decreased capacity due to 'voids' in the load being created along the sides of the body.

CONTAINER LIFT SYSTEMS

Early on, the Load-Master was available with lifting hoists to accommodate virtually any type of rear-load container on the streets. They developed their own sling-type lift, powered by a small ram and mounted over the hopper opening, and 'out-of-the-way' of the crew during hand-loading operations. This twin-cable lift could service the popular Leach Packmaster style containers, which had to be raised by the their side handles.

For larger containers, equipped with a single eyelet at the back edge, a direct-pull hydraulic reeving hoist did the work. These hoists were mounted on the roof of the body structure, similar to the type used on City Tank's Roto-Pac since 1958. Load-Masters could be equipped with either type of hoist, or with both hoists in combination. This equipment, coupled with the large hopper and excellent crushing ability made the LM-100 a versatile and modern refuse collection system. Contractors and municipalities both began to take notice of the new Load-Master. Along with the Leach 2-R Packmaster, the Load-Master would have a profound effect on the rest of the industry, as virtually every major manufacturer of rear loaders embraced the slide-sweep packing method by the mid 1970s. Others went to swing-link systems, or in the case of Daybrook, simply ceased production altogether.

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