The D9 is a series of heavy tracked-type tractors, carried on continuous tracks and usually used as bulldozers. The series began in 1954 with a prototype tractor called the D9X. Ten D9X prototype models were built in 1954.
1. 6. 2010Caterpillar is the best known manufacturer of construction equipment in the world (probably). The company was formed in 1925 by the merger of The Holt Company, (who built its first crawler machine in 1904), and the company of C.L.Best who…