Heavy equipment refers to heavy-duty vehicles, specially designed for executing construction tasks, most frequently ones involving earthwork(土木工事)operations. They are also known as, heavy machines, heavy trucks, construction equipment, engineering equipment, heavy vehicles, or heavy hydraulics(水力の、水圧の、液圧の). They usually comprise five equipment systems: implement, traction(牽引), structure, power train(動力伝達系), control and information.