In prewar times, production of the tractor began due to the need for agricultural development. During the war, mechanization of construction was in high demand at places like airports. However, it was the birth of bulldozers that truly started the history of construction equipment in Japan.
In December 1942, a year after the beginning of the World War II, the navy commissioned Komatsu to produce heavy earthmovers for the purpose of building air bases. Since a short deadline was required, Komatsu gathered existing G40 gasoline tractors and attached a hydraulic device and a blade to them rather than making them from scratch. This machinery was called "Komatsu Model 1 Cultivator", and it was the origin of the Japanese bulldozer.148 units were produced by the end of the war.
Some of those bulldozers produced during the war were transported overseas, however, most of them were attacked and sunk on the way.
There were some G40 models working in Philippines during the war. When the war ended, they were taken over by the United States and disposed of in the sea along with other weapons. Later, it turned out that one of them was recovered and was working at a farm in Sidney Australia. This particular G40 returned to its homeland, Ishikawa, Japan in 1979, and made a big news in the media.
Since its first emergence in 1951, it took only 50 years for the hydraulic shovel to establish its primary position on construction sites worldwide. Its size ranges from mini to super size depending on the scale of construction, and during the half century, it kept evolving by achieving a minimum rear-swing radius and adapting styles that would work with characteristics of each site. Mirroring the movement of a human hand, a hydraulic shovel will continue to evolve during the 21st century.