The Landmark Leach Packmaster 2R. This early production model rides atop a custom Hendrickson truck for Haulaway Inc. of Berwyn, Illinois. Early versions of the 2-R can be spotted by the lack of side reinforcement braces on the lower part of the tailgate
    By 1959, Leach Company was riding wave of increased sales that approached 1000 units per year. The versatile 1955 Packmaster was clearly the most advanced rear loader on the market, and was complimented by a nimble container system. Demand for their product was taxing the capacity of the South Main Street factory, which pre-dated Leach's entry into the refuse body business. What happened next might have, at that time, seemed like 'messing with success'; Leach once again re-designed their rear loader. When the smoke had cleared, Leach had come up with a rear loading packer that would forever change the course of refuse body history.
    The new design from Leach engineer and eccentric genius Cyril R. Gollnick was the biggest, most powerful rear loader ever conceived, and was dubbed the Packmaster 2-R. The designation probably refers to the gigantic two cubic yard hopper, which was one third as large as the entire body of the original 1932 Refuse Getter, and fed bodies of 20 or 25 cubic yards capacity. But it was the design of the packer mechanism that was truly revolutionary. Two massive panels, hinged together and working in tandem to clear the hopper and pack refuse into the body. The assembly rode upon four rollers inside tracks in the tailgate sidewalls, and was powered by four double-acting hydraulic cylinders. We now know this system as the 'slide-sweep' method, which is used on the overwhelming majority of rear loaders built today. But it all began with 2-R back in 1959.
Rear view of the Haulaway truck: early versions of the 2-R can be spotted by the lack of side reinforcement braces on the lower part of the tailgate
SLIDE-SWEEP: THE LEACH REAR LOADER REVOLUTION
At the heart of the 2-R packer are two massive panels, the slide plate (1) and sweep plate (2) which are hinged together and act as a single unit. The slide plate is carried in the tailgate by four rollers (5) which are guided by trackways (6) in the hopper side walls. Slide cylinders (3) are attached at their piston ends to a crossmember in the upper tailgate, and at their rod ends to the top of the slide plate for a back-and-forth movement. Sweep cylinders (4) are attached at their piston ends to the upper slide plate, and at their rod ends to the sweep panel to impart a rotary movement.
In addition to its ability to easily swallow and crush large objects, the 2-R design possesses some unique features. First, all four hydraulic cylinders used in the packer are identical, and may be interchanged with one another. Second, during the final stages of the cycle when the refuse is being packed into the body, the piston ends of the double acting cylinders are energized (extending the rods), thereby utilizing the maximum available force of the cylinders.
Note: Leach literature typically refers to reference #1 as the carrier plate, and #2 as the packer plate. The Leach 2-R method has since become almost universally used, and therefore for clarity they are referred to as the slide and sweep panels, in line with accepted industry nomenclature.
Above: 2R packing cycle (courtesy of Michel Ferro)
Click on the image to start the video
    Gollnick's system is so simple, so effective, and today so universally accepted that it is easy to take it for granted. But in 1959, it was radical and new, and there was nothing like it on the planet. The 2-R broke down compaction barriers, socking away 800 to 1,000 pounds of refuse per cubic yard. And the packer was brutally strong, able to crush virtually any appliance, any piece of furniture and even small automobiles, as Gollnick once proudly demonstrated on an old Volkswagen.
    Despite its prowess, the 2-R was no overnight sales wonder. Without exaggerating, it can probably be said that it was way ahead of its time, and was a much larger than the average refuse truck then commonly in use. No doubt, many small haulers didn't know what to do with such a powerful machine. But its reputation grew slowly, as word spread about its awesome packing power. Some of the earliest known sales of the 2-R were to contractors in the Chicago area, an early Leach Packmaster stronghold. Private contractors in the New York City area were also among the first to realize the potential of the 2-R, and would become perhaps its most loyal adherents. Heavy commercial refuse and even demolition wastes were no serious challenge, and high compaction meant substantial savings at a time when tipping fees were often based on body size, instead of net weight. Packing 1,000 pounds per cubic yard, the owner of a 20 yard 2-R could dump almost twice as much trash as the owner of a similar sized Gar Wood packer, for the same price.
This 1960 2-R Packmaster on a Hendrickson cabover was sold to a Chicago refuse contractor
    The 2-R was also the first rear loader capable of efficiently handling large containers. As with the Standard Packmaster, which of course remained in production, the 2-R could pull small cans with its packer blade. But the giant hopper really shined in the four-plus yard container class. Container capacities up to 12 cubic yards could easily be handled. These required an overhead hoist, in the form of a drum winch or a hydraulic reeving cylinder. Leach had already possessed a superior container truck in the Standard Packmaster. The competition, with their hinged hopper, rotary blade and chain-flight packers were already at a disadvantage. With the arrival of the 2-R on the scene, those designs were effectively obsolete.
    If any fault could be found with the 2-R, it would be that it retained the old tilt-to-dump method as used by its predecessors. The tailgate was extremely heavy, approaching two tons by itself. Coupled with a 25 yard box full of highly compacted trash and a soft landfill surface, the original 2-R probably gave a lot of drivers 'white knuckles' . But ejection unloading was about to emerge throughout the industry, and Leach would be no exception.
An early 2-R lifting a 6 yard container with an overhead hoist
    The influence the 2-R Packmaster had on the refuse body industry cannot be overstated. Fifty years after its creation, it is the most widely copied design in history, and its slide-sweep packing method is employed in some form by almost anyone who builds rear loaders today. There are many variations in cylinder placement, and some designs substitute slide blocks in place of rollers. But the 2-R did it first, and over the years would become one of the most recognized and best-loved refuse trucks of all time.
    Among modern rear loader designs, only the 'swing link' method has ever offered any serious competition to Gollnick's slide-sweep system. From an engineering standpoint, the low-friction swing link packers are arguably better in many aspects, but not so much so that they have rendered slide-sweep obsolete. Even so, swing link packers all use a two-panel system, a method which was pioneered by Cyril Gollnick's 2-R Packmaster. And few packers have ever matched the enormous 'bite' of the 2-R, which can eat virtually anything than can be crammed into its mammoth hopper.
    Consider how the industry changed in just the first ten years after the introduction of the 2-R Packmaster by looking at Leach's competitors, before and after the 2-R:
Competitor
1959
1969
Daybrook
Power-Packer, a continuous feed RL
Daybrook's continuous feeding Power Packer was a complex machine, best suited for light, residential refuse. It had little ability to handle bulk objects, or containers of 4 cubic yards and bigger. Daybrook was sold, and the new owners ceased refuse body production altogether in the mid 1960s
Gar Wood
Load-Packer 600, a chain driven rotary panel RL
By 1969, Gar Wood was reeling from disastrous attempts at unitized trucks (T-series) and a groundbreaking but troublesome swing-link packer (LP-800), and was headed for bankruptcy. Only a tweaked version of the old 600 (the LP-700) sold in any significant numbers, and these were strictly limited in their ability to handle bulk refuse.
Heil
Colectomatic, a hinged-hopper RL
In 1960, the Mark II Colectomatic was introduced with telescopic compaction/ejection and a greatly simplified packer. It was an excellent design and remained popular for many years, but could never compete with 2-R's crushing power and container handling ability. A totally unique new bulk packer, the Mark V, was introduced in 1969 using a combination swing link and telescopic platen method. The Mark V was an excellent answer to the 2-R, but it was a short-lived victory; Heil was (in later years) successfully sued by Leach for patent infringement. In fairness, the Mark V was a unique and innovative design, with Heil seeming to go out of their way to avoid copying the 2-R. But Leach's legal victory stood, and would effectively kill the Mark V in the United States.
Pak-Mor
I-Series barrel truck (side loading)
Pak-Mor wasn't building a rear loader in 1959, but is here included because they introduced two RL models during the 1960's, one of which (the RL-200/300 series) utilized the Leach two-panel slide-sweep method
Roto-Pac (City Tank Corp.)
Roto-Pac, a chain-flight rear loader
Roto-Pac was perhaps the most primitive design on the market in 1959, dating back to the 1920s. By 1964, City Tank had introduced the Load-Master, the first real competitor to the 2-R. It was also a near-copy, and Leach considered a lawsuit but never filed, perhaps because they considered Load-Master only a minor threat, being a somewhat 'regional' east coast brand. Roto-Pac remained in production in 1969, but was near the end of its run. Except for DSNY purchases, it is unlikely it would have lasted as long as it did. The Load-Master was a good packer in its own right, but borrowed heavily from Leach's 2-R design.
Sicard
Sanivan SM-4, a hinged hopper RL
Although Sicard deserves credit for some critical breakthroughs in the refuse body industry, (most notably ejection rear loaders) the complex Sanivan never really caught on. Sicard's USA plant actually stopped building Sanivans in 1958, and the remaining Canadian-built version did a fast fade during the 1960s
Lakeland, Florida bought eight of these 20-yard 2-R's in 1962, which replaced twenty smaller packer trucks!
In the early 1960s, private haulers in the New York area began a love affair with the 2-R that continues to this day. Here we see a typical early example of a 'NYC Special' from Allegro Carting: super heavy-duty conventional cab truck (REO) with a 2-R Packmaster body, lots of trim and a spectacular paint job.
Truck 414-T in the Newark, New Jersey fleet was one of six Leach 2-R Packmasters added in the early 1960's. The 25 yard bodies, all on Diamond T trucks, doubled as snow fighters
The driver of truck 414-T raises the tailgate in preparation to dump. The early 2-R still had the tailgate cylinders mounted inside the body
An early-model 2-R with 25-yard body
Even the small cans used on the original Standard Packmaster could be adapted for overhead hoist dumping with the 2-R by simply welding a hook on the bottom
Later-model 2-R tilt-dump body; on residential routes, record setting loads were now possible