They are called Off Road Trucks or Quarry Trucks, the largestest ones are used in mining operations. They are so big that they have to be assembled at the location. Then think of the moster Backhoe to load them, they ususally try to get them loaded in one or two bucket fulls.
LOL, hubby is an operating engineer and I was bone and raised around this stuff. Normal girls played with dolls, I had construction equipment. Even had a real dozer in my yard for a while to climb on.