Here’s an illustration that shows
what happens when a tire hits the
berm. Most berms in the nation’s
mines are constructed of a soft
material. The first thing a tire
does when it goes into this earth
berm is to sink in. MSHA policy
states that berms be at least mid-
axle height to the largest
equipment that uses that road. For
example, if the mid-axle height of
our largest piece of equipment, or
half way up the wheel, is three
feet, we would have to have a
berm that is at least three feet