Why do school buses have chains on the undercarriage?

Answer 1

These chains can be swung out by the driver (inside the vehicle) to drop just in front of the drive wheels to improve traction when weather conditions require their use If some of you don't know what these are, here are a few pictures. Back then we had to twist a lever, kind of like a garden hose faucet. Now I'd immagine they have an easy to use switch. You just turn on the chains and they drop from the bottom of the bus. They get spit out and land under the tires for traction and spin as the wheels move. They don't actually wrap around the tires, they just catch under them where it's needed most. No need to have to manually wrap all the tires of a 100 bus fleet. Totally automatic. It's really a neat thing to see them in action!

http://www.slaglefire.com/equipment-onspot.htm

http://www.onspot.com/indhisfr.htm

http://www.sartinservices.com/onspot/BP_onSpot.htm

http://www.hamilton-co.org/engineer/Images/NewDumpTruckNewdump3.jpg

http://www.vonslatt.com/bus-body.shtml Yes on the newer buses there's a toggle switch for them, there known as on demand chains