Classic Refuse Trucks GAR WOOD

Load-Packer 600

After a relatively short production span for the LP-500, the Cyclomatic Gar Wood packers were restyled in early 1959 and badged as a new series, the LP-600. The packing method remained unchanged, with a chain-driven rotary conveyor panel feeding a hydraulic packer blade. The big change in the 600 was the packer blade hydraulic cylinders, which were relocated behind the panel and inside the body. Because one end of the cylinders was attached to the upper body, they now performed the dual functions of packing the load and raising the tailgate for unloading.

Touted as a weight-saving and feature that also simplified the design, the dual-function cylinders may have been merely an attempt to match features with the rival Heil Colectomatic. If so, Gar Wood may have soon regretted the decision when Heil forever abandoned the dual-function cylinder concept later that year with the introduction of the landmark Colectomatic Mark II. Whatever the reason, Gar Wood would stick to their guns, and the LP-600, for the next five years

With the packing panel cylinders now located forward of the panel and inside the storage body, these critical components were left exposed to the compacted refuse load and much more susceptible to damage. In later versions, Gar Wood reverted back to external cylinder mounting (as on the LP-500) and then criticized another competitor's model for using similar cylinder placement!

When ready to unload, the tailgate latches were released, and the packing panel retracted which pushed open and raised the tailgate. The operator controlled this function safely from a lever at the front of the body. An underbody hoist cylinder tilted the tapered body to dump the load in the conventional manner.

DUAL FUNCTION CYLINDERS

In one method described in the LP-600 patent, the rotary conveyor panel (green highlight) as shown at position (A) blocks rearward movement of packing panel. Spring-loaded, one-way latch buttons (yellow) on either side of tailgate hold sweep panel elevation at hook (B). The operator then manually locked clevis pins into bores on either side of sweep panel (C) which secured it in this position.

With the clamps released and the packing cylinders energized, the tailgate assembly was raised upward by the cylinders pushing against the locked conveyor panel. This method would allow for the use of a shorter stroke cylinder. However, it can not be verified if this method was actually used in the 'as built' version of the LP-600.

Indeed, surviving visual evidence seems to indicate that this method was never actually in production. Long-stroke cylinders were used instead, which merely pushed the packer panel fully rearward to its stop point, after which the the unlatched tailgate was forced open through the remainder of the stroke.

As on the LP-500, the conveyor panel was used to block the packing panel, but this was to prevent it from creeping back as the body became filled. This occurred automatically at the completion of the packing cycle. In later versions of the LP-600 (and LP-700), the problem of panel creep seems to have been tackled by other means, probably by changes in the the hydraulic circuit.

Externally, the LP-600 was dimensionally identical to its predecessor, but can be easily identified by a few visual cues. As shown above on this 1959 City of Dayton truck, the bracing ribs on the tailgate were changed to a triangular pattern which supported the rotary panel stub shafts. Also, the ribs reinforcing the packer panel (which were exposed on the LP-500) were now covered by a flat steel sheet.

This sixteen-yard 1961 model was owned by the City of Buffalo. It shows the compact chain drive arrangement for the conveyor panel, which replaced the bulky and protrusive version used on the LP-500. This revised configuration freed up room for workmen using the riding step, and would remain unchanged through the 1970s. The hopper door was optional equipment.

Beginning with 1962 models, a hinged access cover was added on the right side to protect the linkage and the valves, which were now positioned outside the tailgate. Reinforcement bracing on the sidewalls once again reverted to the radial pattern of 1957-58. Twenty-five cubic yard bodies were one again listed in the option sheet for high-volume routes. Gar Wood literature of this period emphasized the light weight and simplicity of their tilt-dump bodies compared to the Heil Colectomatic Mark II. However, they were really just marking time until their own ejector bodies could be readied, as was the rest of the industry. Gar Wood would be the last of the "big three" refuse body builders to get an ejector model on the market, and was even behind the upstart Load-Master in this regard.

GAR WOOD LP-600 VINTAGE FILM

A rare film (shown in two parts) of a Gar Wood LP-600 in action at a U.S. Army base in Augsburg, Germany circa 1962

Courtesy of Michel Ferro

8/1/04 (revised 10/9/11)