What Happens to Your Trash Inside a Garbage Truck

What happens to your trash inside a garbage truck? The blade sweeps your bag in and packs it against a wall that keeps backing away. So why would you build a garbage truck compactor with a wall that gives way? It decides how much of your street one truck holds, and on a bad day, it's what saves the truck. We follow your bag into a typical rear-loader garbage truck: why the wall starts the day at the back, how one set oil pressure gives the first bag of the morning the same squeeze as the last, and why squeezing harder runs into the weight limit on each axle. Then the squeeze meets a battery, and we find out why crews are trained to dump a burning load in the road, and why that plan only works because the wall can move. Chapters 0:00 A wall that backs away 1:02 The first bag of the morning 2:18 Why not squeeze harder? 3:08 What the wall can't feel 3:57 A fire you can't reach 4:53 Dumping the load on purpose 5:50 Why the wall gives way Sources Packing cycle of about 15 seconds (one maker's figure): The Heil Co., PT1000 rear loader brochure (2025). https://heil.com/wp-content/uploads/2... The wall's set resistance, even packing, weight moved to the front axle, and the wall pushing the load out: McNeilus, US Patent 7,108,473, "Rear loader variable packing density system" (2006). https://patents.google.com/patent/US7... Looser loads up front in older trucks: The Heil Co., US Patent 4,690,607 (1987). https://patents.google.com/patent/US4... About three binfuls into the space of one: BC Ministry of Environment, "Guidelines for Establishing Transfer Stations for Municipal Solid Waste". https://www2.gov.bc.ca/assets/gov/env... Loose vs compacted trash: US EPA, "Volume-to-Weight Conversion Factors" (April 2016). https://www.epa.gov/sites/default/fil... Axle weight limits: US FHWA, "Bridge Formula Weights" (FHWA-HOP-19-028, 2019). https://ops.fhwa.dot.gov/freight/publ... Twice the weight, roughly sixteen times the road damage (a rule of thumb): City of Spokane Public Works, "Pavement Performance Considerations for Heavy Traffic Loads" (2004). https://www.inlandrail.org/documents/... Crushed lithium-ion batteries, trash fires and the haulers' dump protocol: US EPA, "An Analysis of Lithium-ion Battery Fires in Waste Management and Recycling" (EPA 530-R-21-002, July 2021). https://www.epa.gov/system/files/docu... More than 1,200 battery fires in a year in UK bin lorries and waste sites (an estimate scaled up from a council survey): Material Focus, 10 May 2024. https://materialfocus.org.uk/?press-r... Indianapolis, January 2015: US NHTSA Office of Defects Investigation, PE 15-006. https://static.nhtsa.gov/odi/inv/2015... Slough, May 2025: Slough Borough Council, news, 12 May 2025. https://www.slough.gov.uk/news/articl... Credits Written, researched and animated by Made Ordinary. Music: "Vestige" by Lennon Hutton, via Epidemic Sound Sound effects: Epidemic Sound #garbagetruck #engineering #howitworks