Garbage Trucks and Trash Container Breakage: Understanding the Compaction Process

When garbage trucks compact the trash inside them, it is not unusual for containers within the trash to break. This compaction process is designed to maximize space efficiency by compressing waste materials. However, the significant pressure involved can lead to the crushing or breaking of various types of containers, such as glass bottles, plastic containers, or cardboard boxes. In this article, we will explore the dynamics of this compaction process and why certain containers break while others remain intact.

The Force Behind Compaction

The compaction process in garbage trucks is achieved through hydraulic systems, which create considerable pressure to compress waste. A typical hydraulic system operates at around 3000 pounds per square inch (psi), and the piston diameter of a compactor hydraulic ram is usually in the 4 to 6-inch range. This results in a piston force of approximately 85,000 pounds. At first glance, this seems like an overwhelming amount of force capable of completely crushing anything in its path.

However, the key factor that tames this force is the wide area over which it is distributed. Your typical compactor body has a diameter of about 7 feet. When the force of 85,000 pounds is spread over this large area, the resulting pressure is roughly 15 psi. This is less than the force you can exert with the heel of your foot. Despite this small pressure, it is still enough to cause significant damage, particularly to open or uncapped containers made of flexible materials, such as plastic bottles or cardboard boxes.

What Containers Break and Why

Certain types of containers, like soda bottles, milk jugs, or juice boxes, are more prone to breaking under the compaction process. This is because they are made of materials that can deform and break when subjected to the force. In contrast, stronger containers like cans, glass bottles, or rigid plastic containers can withstand the pressure.

It is worth noting that the compression process does not end with the initial compaction in the garbage truck. Most waste is subjected to further compaction upon disposal at landfills. Large landfills use special machines to shred garbage into smaller particles, further increasing its density and compaction rate.

Surviving the Compaction Process

Despite the high pressure and force involved in the compaction process, many relatively delicate objects manage to survive with no scratches or damage. This often leads to confusion and skepticism. To address this, consider the following points:

The pressure is distributed over a large area, significantly reducing the localized force. Materials with better structural integrity can withstand more force without failing. Special design features in some containers help them survive the compaction process.

As an experienced driver of garbage trucks, I have observed the array of delicate objects that survive the compaction process with remarkable resilience. It is indeed a testament to the strength and design of certain containers that they can resist the significant force applied by these hydraulic systems.

Conclusion

In summary, while garbage trucks do exert considerable pressure during the compaction process, the distributed force means that not all containers break. Certain materials like flexible plastics are more susceptible to damage, while stronger materials like glass and metal can withstand the force. Understanding the mechanics of compaction can help us appreciate the complexity of waste management and the design considerations that go into container construction.