One-man concrete pipe unloading onto tires - GIF

[12bolts]

No pressure in those tyres

...the air pressure in the tires let it right down nice and soft.

They are just empty cases

[hemmjo]

No pressure in those tyres They are just empty cases

There is still a lot of air in those tires, after the pipe falls and closes off the hole in the top tire, all the remaining air has to escape from the the small spaces between the tires. You can see the dust cloud the escaping air makes as the pipe falls.

I have actually seen this method used with concrete pipe. I always wondered how many times it took to learn where to stack the tires?