Tractor, Allis-Chalmers, HD-21

History: Allis-Chalmers produced the HD-21 from 1954 to 1969; and to 1975 with a change in body style and specs as HD-21B. The HD-21 model included seven different variations of design: different body styling, power ratings, weight, air-filter canister placement. The HD-21 was the first Allis-Chalmer's model to use it's own manufactured engine based on the Buda diesel and not on Detroit diesel truck engine. Equipped with a 6 cylinder supercharged engine producing between 204 fwhp (1954 models) to 273 fwhp for 1963 model. They weighed in at 44,000 lbs (1954) to 57,100 lbs (1969 model) without any blade attachment. This means a 70-ton railroad flat car can carry a maximum of 2-3 tractors, depending on loading space and any additional attachments.

Railroad/Company: Allis-Chalmers was a U.S. manufacturer of machinery for various industries. Its business lines included agricultural equipment, construction equipment, power generation and power transmission equipment, and machinery for use in industrial settings such as factories, flour mills, sawmills, textile mills, steel mills, refineries, mines, and ore mills. The first Allis-Chalmers Company was formed in 1901 as an amalgamation of the Edward P. Allis Company (steam engines and mill equipment), Fraser & Chalmers (mining and ore milling equipment), the Gates Iron Works (rock and cement milling equipment), and the industrial business line of the Dickson Manufacturing Company (engines and compressors). It was reorganized in 1912 as the Allis-Chalmers Manufacturing Company. During the next 70 years its industrial machinery filled countless mills, mines, and factories around the world, and its brand gained fame among consumers mostly from its farm equipment business's orange tractors and silver combine harvesters. In the 1980s and 1990s a series of divestitures transformed the firm and eventually dissolved it. Its successors today are Allis-Chalmers Energy and AGCO.