>>When a tractor trailer is parked and is being unloaded with a forklift the wheels have to be chocked.<<
What state is this law in ? Calif? It didn’t used to be and I hauled in 48 states.
Hand brakes are air powered on heavy equipment and the auto- mechanical sets in when the air bleeds off below a certain number.
I should have said, where I worked at.. at least that’s what they told us before we loaded or unloaded the truck.