At large mines overseas. Many construction machines used at oversea mines are extra big. They are too big to be transported as a complete piece, so they are carried by a trailer to mines as disassemble pieces. What do you think would happen if the trailer transporting this equipment had to go through roads that are full of big rocks? That would be too dangerous, wouldn't it? That's when a wheel dozer comes in handy. It runs in front of the trailer and makes the road smooth by removing rocks and other obstacles.

Wheel dozer [THE GREAT PICTURE BOOK OF CONSTRUCTION EQUIPMENT]