Classic Refuse Trucks GAR WOOD

Chapter 18
Load-Packer 900 Series

With the 1970 takeover of Gar Wood Industries, and the drastic downsizing that resulted, Gar Wood Division (formerly Wayne Division) remained as the anchor of the company, and included all of the remaining equipment lines not sold off during the transition period. By 1972, the product family had been reduced to dump bodies and hoists, cranes, lift-gates, dump trailers, and roll-offs, in addition to the refuse bodies. During this transition period, new owner Sargent Industries made no changes to the refuse line, which still consisted of the Load-Packer 700 and 800 series, T-100 and Load-Runner, all holdovers from the 1960s.

The refuse bodies, which would become the primary product built by Gar Wood Division through the remainder of the decade, were therefore in dire need of updating. Obviously, there would be no redemption for the T-series unitized refuse trucks, which had started of all the trouble in the first place. It is uncertain if any T-series were built after 1969, although they remained in the catalog for a few more years. The LP-800 packer body was a far more salable product, but was itself somewhat problematic, and its similarity to the T-series mechanism probably didn't help either. The one bright spot in the line was the LP-700, an aging but versatile design that already had established itself in the industry. It was light, fast and packed a good load, and had been updated to full-ejection discharge in 1965. Though unable to compete with larger 'bulk' packers, it was still a municipal and contractor favorite. More than any other product, the LP-700 probably saved Gar Wood from complete disaster in the late 1960s, and was capable enough to remain for a few more years as a mid-range residential model.

    To overhaul their product line, Sargent Industries needed some innovative thinking. Reaching outside of the industry, they recruited Fred T. Smith, who was then working as Director of Research at the Whiting Corporation, which specialized in overhead cranes. His first task at Gar Wood would be to design a heavy-duty, high-compaction rear loader to anchor the division. Competitors at that time were fielding some of the biggest, most powerful designs ever seen. There was the vaunted 2-R Leach, which had pioneered the concept and reigned supreme among bulk packers. It was soon joined by the Pak-Mor 300, Heil's fantastic Colectomatic Mark V and a rugged new Load-Master 400 series. Equaling any of these packers would be challenging. Fortunately, Fred Smith would be ready for the job, despite having had no prior experience in the design of refuse equipment.

    Initially, the plan was for the existing model LP-800 to be saved, with any engineering shortcomings corrected. But Smith considered the 800 a "fiasco", and recommended starting over with an all-new design. Given the green light for the project, he set about the task of creating the next generation of Load-Packers. What Smith came up with would have been unthinkable in the dark days of 1969: an advanced-design high-compaction rear loader that would not only revive the Gar Wood brand, but also become one of the best selling rear loaders in history. Rushed into production, it went on sale in the fall of 1972 as the Load-Packer 900 series, and was radically different from anything on the market, both in function and appearance.

    Externally, the LP-900 looks deceptively like a slide-sweep packer, with an upper and lower panel working in concert to lift and pack refuse from the hopper. However, it is in fact a swing-link design, with no rollers or slides connected to the upper panel. In this respect, it actually has more in common with the LP-800, albeit with some critical differences. Two heavy links, mounted externally of the hopper, support the packer panel pivot shafts, which protrude through arcuate slots in the sidewalls. Outboard-mounted cylinders lift and lower the assembly through the tailgate, while smaller stabilizer links control the top end of the upper panel. The lower sweep panel is fairly conventional, and is pivoted by smaller cylinders affixed to the upper panel.

INSIDE THE LP-900 TAILGATE

Loading position: 2.5 cubic yard hopper ready to receive material. The long cylinders, which operate the upper panel are mounted outside of tailgate sidewalls and are retracted, while the short cylinders, which operate the lower panel are extended. Any previously loaded material is retained.

The entire packer assembly is carried on the bearings of four links. Two long links are located outside the tailgate side walls, and bear most of the packing forces. These links are connected to the ends of stub shafts that pass through curved slots in the tailgate sidewalls. These shafts also join the pivoting lower panel to the upper assembly. Two more short links are mounted high inside the hopper, and serve to stabilize the upper panel.

Note the arc of the slots, which trace the travel path of the lower links. These are not tracks, and there are no rollers. Rather, the slots serve as a pass-through only; no part of the packing mechanism makes contact with the tailgate in this area.

Also note how the front wall of the tailgate is nearly vertical, with a gently curved surface. The hopper floor is formed from a single curved sheet. This allows for an unusually deep and spacious hopper within compact dimensions, of inherently high strength. Tailgate overhang is minimal in relation to capacity. The partition, which separates the upper tailgate from the main body, is also gently curved and will aid in the compaction process.

Operator pulls control lever rearward to commence automatic packing cycle. The short cylinders retract, opening the lower panel over the loaded hopper. At this point, the panel is high in the tailgate structure, minimizing 'trimming' of loaded refuse. Hopper can be generously filled as a result.

A regeneration valve is incorporated into the LP-900 hydraulic system. During this stage of the packing cycle, the valve sends expelled oil from the small cylinders to the rod ends outside cylinders, preventing the packer assembly from dropping while the lower panel retracts.

Once the lower panel fully retracts, the regeneration valve shifts, allowing oil to flow out of the rod side of the outside cylinders. The mechanism descends rapidly under its own weight. As the assembly lowers, the oil expelled from the rod ends of the outside cylinders combines with oil from the pump to keep the lower panel in the open position.

Because of the arcuate path of the links, the mechanism initially moves rearward, and then follows a gradual downward arc until the reaching the end of the slots, at which point the travel path is nearly vertical. The smaller links keep the assembly in an upright position throughout its travel.

Once the mechanism is fully lowered, the convex-shaped inner surface of the upper panel forms a restricted passage into the body. This narrowing of the passage is mostly invisible from the outside, but plays an important role in the next phase of the cycle.

Next, the short cylinders extend under pressure, pivoting the lower panel and sweeping the hopper floor clean. It is here where the "Dyna-Action" of the LP-900 begins, which sets it apart from conventional slide-sweep designs.

The curved inner surface of the lower panel imparts a rolling action on the load as it sweeps the hopper. The high volume of loaded refuse being forced through the narrow passage starts the compaction process. The arrows trace the refuse as it begins its "torturous path" into the body, much like being forced through a funnel. It is crushed against the front wall, the curved surface of the upper panel, and finally against the surface of the upper tailgate partition. These three surfaces help to roll and pack the refuse, and their curved construction makes them inherently strong and resistant to stress.

In the final phase, the long cylinders retract under high pressure, and the packer assembly is pulled upward and inward, lifting and packing the refuse into the body. The bearing surfaces of the links offer little frictional resistance, and thus most of the cylinder force is transmitted directly to the load.

As the mechanism reaches the end of its upward travel, its arcuate path gradually changes the motion from a near-vertical lift to an inward thrust, with the curved partition further guiding the refuse inward.

Compacted refuse is retained, hopper is ready for the next batch of refuse.

On the outside, the LP-900 tailgate and body appear quite angular, and almost conventional. Inside the tailgate however, it is a study in the use of the curve for both strength and increased packing efficiency. The curved packing panels are incredibly strong, especially compared to the flat panels that had heretofore been employed in most rear loaders, which required heavy bracing and reinforcement. The arc of travel taken by the mechanism results in short tailgate overhang, as opposed to conventional slide-sweep designs in which the panel travels in a straight line. This also gives the LP-900 an extra inward thrust near the end of the cycle.

In conjunction with the curved shape of the hopper floor, the front wall and the partition, a unique narrowed passage is formed that constricts refuse, yet resists distortion and buckling under the high compaction forces. Because the mechanism is entirely supported on the four links, with no tracks or rollers, less hydraulic force is wasted overcoming friction. The LP-900 delivers more of its packing punch directly to the load.

GAR WOOD LOAD-PACKER 900: PREPRODUCTION MODELS, 1970-1972

    Warren Seward lived in the Buffalo, New York area during the 1960s and 1970s and has a working knowledge of many of the area refuse haulers during that time As was the case in many larger cities, Gar Wood refuse bodies had a strong presence there. Additionally, Warren has first-hand knowledge of prototype or pre-production LP-900 packers, which were in use during the early 1970s, a full two years before the official nationwide rollout of the 900 series in September 1972. These early versions of the 900 packer were much different than the final production models, and were in fact coupled to the Gar Wood ejector bodies of the 1960s style as used on the 700/800 series Load-Packers.

    In 1970, Gar Wood Industries was purchased by, and became a division of Sargent Industries, an agglomerate that had a reputation for turning a profit from failing companies. Undoubtedly, Gar Wood had indeed fallen into the failing category by 1969, after years of virtually dominating the refuse body industry. A disastrous foray into building unitized refuse trucks of immense proportions (the T-Series) had fallen flat, and was followed by the hastily-conceived LP-800 bulk packer. The 800 was the first ever swing-link packer, and had good potential, but was dogged by quality-control problems and may have been hurt by its resemblance to its predecessor.

    To turn Gar Wood around and restore it to its former glory, Sargent Industries was faced with a choice to either "fix" the troubled LP-800, or replace it with an entirely new model altogether. Ultimately, the decision was made to kill the 800, at the behest of engineer Fred Smith, who would be tasked with coming up with its replacement. That replacement was the LP-900 series, which is today well known as the Formula 5000 by Heil. Despite the urgency of getting the new Gar Wood high-compaction rear loader into production, some field-testing would certainly be needed, and this is where Warren Seward's recollections get interesting.

A 1960s White Compact with Gar Wood LP-725 body owned by Niagara Sanitation Company.
Click here to download the original ad from 1969.

    Like Gar Wood, the company that Warren worked for, Roy Wingdale Disposal, was also to be sold around this time. Wingdale sold his business to Nick Bodnar, who hauled under the names Niagara Sanitation Company and Trash Lovers Co. (TLC) in the metro Buffalo area. Bodnar also was the owner of Buffalo White Trucks, an established heavy-duty truck sales and service center. Warren writes:

    "When Nick Bodnar bought out Roy Wingdale Disposal in January, 1970, he ran Roy's old trucks for about six to eight months, and phased in the new units in the summer of '70. I distinctly remember seeing that summer, the first of three new White Compacts with the new Gar Wood 900 tailgate mounted on the old 700/800-style ejector bodies T.L.C. Disposal had purchased. Nelson Miller, who owned Amherst Disposal, also bought a new White with the 900 -700/800 style body in early 1971."

    If the first LP-900 tailgates appeared in Buffalo during mid-1970, that would be a full two years before the 900 was unveiled in a national advertising campaign. The use of the LP-700/800 ejection body gave Gar Wood a ready platform to which the new tailgate could be "bolted on" for tests under actual working conditions. The popularity of Gar Wood in Buffalo, and its close proximity to Gar Wood's Detroit-based operations would have made that city a logical choice for testing. The fact that Nick Bodnar was in the refuse hauling business and also owned a full-service truck repair facility would have probably made Buffalo and Niagara Sanitation even more attractive choice for experimental models. Being new designs and probably hand-built at Gar Wood's Wayne factory, the prototype tailgates would undoubtedly need occasional repairs or modifications, which could be done at Buffalo White by their own technicians or in conjunction with Gar Wood personnel. These pre-production tailgates may have been installed on new or used 700 bodies in the field. But the use of the 700 series body wasn't the only difference, as Warren continues:

    "One other thing comes to mind on the early 900's I worked on: all three had the electrically-operated packer controls. It was odd because they didn't have any levers to override the travel of the packer during cycling, only a 'jog' switch that you could manually adjust the packer in travel. I personally didn't like them, and most of the other guys didn't either. I heard they had problems with them shorting out in heavy rains. Roy's 800 model had both the electrically operated packer and levers...But for some reason, the early 900's we had didn't have any levers."

    The use of push-button electric controls would seem to indicate that Gar Wood intended to try and work the bugs out of their system, which had been used on both the T-100 and the LP-800. Electro-hydraulic controls had been used by Heil throughout the 1960s, as well as in Europe, where such systems are today in greater use than in America. For whatever reason, the push-button controls never made it to the production model LP-900, which used conventional mechanical linkage to operate the packer control valves.

Composite of a 1976 LP-900 tailgate and a 1960s LP-725 body on a White Compact chassis
to illustrate what the pre-production prototype LP-900s looked like in 1970-71

By the fall of 1972, Sargent Industries had moved all Gar Wood refuse body production to their factory in Enterprise, Alabama. This included the LP-900 and LP-700-9, which shared the now familiar slant-pillared ejection body with open-front construction. The "box body" of the LP-700/800 was discontinued. As of this writing, there are unfortunately no known photographs of these pre-production LP-900 models. Gar Wood probably wanted them kept under wraps, as much as was possible at the time. And while there were probably many photos and films taken by Gar Wood for internal use, these were presumably lost when the company ceased operations in 1979.

CRT wishes to thank Warren Seward for sharing this valuable information.

THE "9" SERIES BODY

Joined with the innovative new 900-series tailgate was an equally unique and striking body. The radical new shape was as attractive as it was functional, distinguishing it from anything else on the street. The 9-series body would become standard on all Gar Wood rear loaders during the 1970s.

The lines of the 9-series are not a cosmetic gimmick, but are purposely designed to form a structure well suited to withstand the intense forces inside a high compaction rear loader. The curved roof, formed from a single sheet in tension to resist pressure, also repels water and reduces corrosion. A conduit formed into the roof protects the hydraulic and electric lines running from front-to-back. Sidewalls bear vertical columns, angled forward from floor to roof, which helped alleviate stresses. The reinforced floor features a side-fold design, bent upwards to form a watertight dam where it joins the sides. The front of the body was typically open, but could be fully enclosed if so ordered.

Attractive and functional 9-series body. Note conduit formed into inside of curved roof (inset)

Ejection was by an angle-mounted telescopic cylinder, as had been the practice on the LP-700 and LP-800. The Constant Density Compaction System (CDC) system used on Gar Wood rear loaders since 1965 was retained for the 9-series body. With CDC, forward movement of the ejector was controlled by pressure sensors in the packer panel cylinders, instead of relief valving of the ejector cylinder as in competitive designs. Packing pressures remained uniform throughout the entire load, unaffected by frictional resistance of the load against the walls and roof, or variances in telescopic ejectors through different stages of extension.

Two concave-curved sheets are used to form the ejector panel, in tension with an angular framework. Initially, the 9-series body was offered in 18, 20 and 25 cubic yard capacities (for the LP-900). In mid-1977, a 32-yard body was added for the 900 series, making it the biggest Gar Wood Rear loader since the T-140 of the 1960s. For an even more attractive look, striping packages were available to customize it to the customers' specification.

9-Series ejector panel showing framework supporting pre-stressed panels

    Designing and bringing any completely new product to market is usually not without a fair share of initial difficulties, and the 900 was no exception. Built at an all-new facility in Enterprise, Alabama, the push to quickly get it into production resulted in some early failures. However, once these initial problems were corrected, the LP-900 began to show its amazing prowess. Fred Smith recalled some of these early experiences in a 2003 interview with the author:

    "The big problem was in those days was we didn't have have FEA, Finite Element Analysis, to help us with the design. Even though I was fairly good with stress analysis and that type of thing, it's not the same as FEA where you can do such a complete job of finding where the stresses were. Actually, refuse trucks, you'd think that they were simple things to design, but you've got some awful big forces running around in there."

    "..we had a tortuous path for the refuse to go. In other words, it would go up and then turn a corner and go in the other direction, under high pressure. This would tend to make the garbage condense more. Then we had used, the first time anybody had used, really high strength steel in the hopper and the blades, and we were using what we call Sargalloy, which was nothing more than, like T1 steel, heat-treated, in the hopper. As a result we could pack 250 gallon fuel tanks in there, and we could pack small cars in it. I even packed the big bathtubs they used to make out of one casting, pack them in and break them up."

City of Chicago LP-920 on White Xpeditor chassis

    "...the City of Chicago bought a fleet of them, to do nothing but pick up bulk...they had one day a week where people put out their bulk and they'd just go down and pick up washing machines and all that kind of stuff. That's one of the reasons we had some failures, in the early days, because it would almost over-do the strength of the steel welds. It turned out that a lot of the welding really wasn't up to snuff. When we had the welding done just right it worked pretty good, so we ended up having what we called an "M" weld, and that weld had to be tested almost like, for space work. Gradually, we got everything to the point where it panned out pretty good. We had an engineer by the name of Jack McKinney, that designed a lot of things for the aircraft industry, and Dan Burns brought him in. So he went over our stress analysis and everything and helped us work on it. He says it's sure a lot easier to design an airplane than it is a garbage truck."

    Introduced concurrently with the LP-900 was The Silencer, which was the trade name for a hydraulic pump designed to reduce the noise produced by refuse trucks during the packing cycle. Engine speed during the cycle was reduced from 2,500 RPM to a mere 600 RPM. In addition to a 75-percent noise reduction, The Silencer saved on fuel and maintenance and cut exhaust emission levels. It was available option on any Gar Wood model, and could be retrofitted to older packers and competitive makes as well. Sargent Industries applied for patents, but abandoned the process when research discovered existing patents that had already been granted outside of the refuse industry. However, it was one of the first pack-at-idle systems offered by a major manufacturer, and yet another example of forward-looking technology coming out of the revitalized Gar Wood division.

    By the mid-1970s, the LP-900 was proving to be a resounding success, finding buyers small and large across the country. New York, Detroit, Boston, Baltimore, Cleveland, Dallas and Sacramento were early users of the 900. The City of Chicago bought a fleet of them for bulk routes, some of the most grueling duty a packer will ever experience. Atlanta switched to the 900 while simultaneously implementing a modern new USS Rollawaste cart dumper system. The LP-900 represented a complete turnaround for Gar Wood Division, which had just come out of a difficult period marked by oddball engineering, financial troubles and then new ownership. At last, the company was once again poised to reclaim the mantle of "industry leader". Ultimately, this design would outlast Gar Wood itself. Under various manufacturers worldwide, it remains in production to this day and is one of the most popular rear loader designs in the world. Moreover, it is one of the few rear loader concepts to have successfully challenged the slide-sweep method so prevalent throughout the industry.

LP-925 on Chevrolet Steel-Tilt chassis

City of Atlanta LP-900 dumping USS Rollawaste 82-gallon cans in 1975

In 1974, Lancaster, NY replaced four smaller packers with these two Gar Wood LP-925s on Brockway tilt-cab chassis

Extra-deep, easy to load hopper holds 2.5 cubic yards (later up-rated to 3 yards)

Color-coordinated striping, customized with the company name, was an attractive option. Shown here is an LP-925

A screen shot from a film of a late 1970s LP-925 in Montreal. While not conclusive,
it appears to reveal a sweep panel with rectangular reinforcements, otherwise unknown on any LP-900

LP-925 on a Kenworth Hustler LCF chassis

SELECTED PATENTS

Patent #	Description	Inventor	Assignee	Date
US3899091	Refuse Collection Apparatus	Smith	Sargent Ind.	June 19, 1972

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