Another popular system for the rear loader is a rear load container specially built to fit a groove in the truck. The truck will have a chain or cable system for upending the container. The waste will then slide into the hopper of the truck.
The modern rear loader usually compacts the waste using a hydraulically powered mechanism that employs a moving plate or shovel to scoop the waste out from the loading hopper and compress it against a moving wall. In most compactor designs, the plate has a pointed edge (hence giving it the industry standard name packer blade) which is designed to apply point pressure to the waste to break down bulky items in the hopper before being drawn into the main body of the truck.
Compactor designs have been many and varied, however the two most popular in use today are the "sweep and slide" system (first pioneered on the Leach 2R Packmaster), where the packer blade pivots on a moving carriage which slides back and forth in large tracks fabricated into the body sides, and the "swing link" system (such as the Dempster Routechief) where the blade literally swings on a "pendulum"-style mechanism consisting of links which control the arc of the blade's movement. The Geesink GPM series uses a pivoting packer blade which swings on an inverted U-shaped frame which lowers the blade into the hopper, where it sweeps the waste out; the frame then retracts back into the body to perform the compaction action. The Heil Colectomatic is a hybrid between the two philosophies- it used a combination of a lifting loading hopper and a pivoting sweeper blade to clear and compact waste in anticipation of the next load.
So-called "continuous" compactors were popular in the 1960s and 1970s. The German Shark design (later Rotopress) used a huge rotating drum fitted with spiral shaped paddles to draw waste in, and force it around an auger of decreasing pitch to compress it. SEMAT-Rey of France pioneered the rotating rake system (also used in the British Shelvoke and Drewry Revopak) to simultaneously shred and compress the waste as it is loaded. Other systems used a continuously rotating Archimedes' screw to draw in waste and mutilate it inside the body. A mixture of safety concerns, and higher fuel consumption has seen a decline in the popularity of continuously compacting garbage trucks, with only the Rotopress design remaining in production due to its niche in being able to effectively deal with green waste for composting.
A unique rear-loading system involves a rear loader and a front-loading tractor (usually a Caterpillar front loader with a Tink Claw) for yard waste collection (and in some cities, garbage and recycling). The front loader picks up yard waste set in the street, and then loaded into the back of a rear loader. This system is used in several cities, including San Jose.
