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.
Around this time, many trial samples were made including a model that was enlarged and fitted with a V8 controlling engine, a model that was equipped with an air-cooled controlling diesel engine, a light weight G25 bulldozer for air transport by glider, etc. None of these were mass-produced before the war ended. This particular model was made as a trial sample of a bulldozer to improve productivity under pressure of increased engineering work. It became a prototype of the D50 bulldozer that was later fully developed.
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.