The thing that causes the most damage is a device called a pusher which knocks the bags from one conveyor to another.

It is a fierce device 'cos bags can weigh 80 pounds or more and are moving at high speed. It doesn't know that your guitar only weighs a few pounds so it gives it the same heafty clout as it would a big bag.

Purolator do not use pushers in their handling hub, they use gravity slides.