Some kinds of earth moving equipment can be unbelievably massive. My dad worked for a company that manufactured earth movers and he took us all to an open house tour one weekend. There was a dump truck that was literally the size of a house, and I got to stand under one tire. It was 16 feet tall. My dad said they used these trucks to haul away coal in those huge strip mines in other countries. This was back in the 1970s, so I'm sure there's much large earth moving equipment being made today. It just amazes me that one or two people can drive something that big.