The largest engineering vehicles and mobile land machines are bucket-wheel excavators, built since the 1920s. The use of tracks became popular for tanks during World War I, and later for civilian machinery like the bulldozer. The first commercial continuous track vehicle was the 1901 Lombard Steam Log Hauler. The first mass-produced heavy machine was the Fordson tractor in 1917. is a present-day brand from these days, starting out as the Holt Manufacturing Company. The early 20th century also saw new electric-powered machines such as the forklift.
Mechanical transmission was in many cases replaced by hydraulic machinery. Kerosene and ethanol engines were used, but today diesel engines are dominant. During the 20th century, internal-combustion engines became the major power source of heavy equipment.
The design of a core tractor evolved around the new steam power source into a new machine core traction engine, that can be configured as the steam tractor and the steamroller. With the advent of portable steam-powered engines the drawn machine precursors were reconfigured with the new engines, such as the combine harvester. Until the 19th century and into the early 20th century heavy machines were drawn under human or animal power. Horse-drawn Fresno scraper digging water-supply ditch
