Allis Chalmers’ Model B tractor a key part of farming history

MACHINERY: It is 80 years since the pioneering model was launched

One of the most significant models of tractor was launched 80 years ago when Allis Chalmers unveiled its Model B tractor.

This tractor was one of the first to be specifically designed for smaller farmers. Previously American tractor manufacturers had built huge tractors to help break up vast areas of the prairies in the early 20th Century.

After much of this was accomplished thoughts turned to produce smaller machines for farms further east.

The Model B took this ethos further by offering a tractor for even smaller farmers who used just one or two horses.

Indeed, the Model B was advertised as the tractor to finally replace the draught horse. AC used Waukesha engines for the 96 tractors built in 1937 thereafter their own power plant was used. This power plant was also used as power unit on their popular All Crop trailed combine harvester.

Because of its intended market the tractor was markedly smaller than many of the others of the period including Allis’s popular Model U.

It was a lightweight machine ideal for working in smaller fields and confined areas. It had a very distinctive appearance with a narrow torque tube connecting the engine to the back end.

This wasp-like waist gave the tractor an enormous amount of room for fitting mid mounted tool bars which allowed it to be a very capable row crop tractor.

Indeed the row crop element was enhanced further when AC offered a larger three-wheel version known as the Model C. AC also experimented with many other formats for the Model B.

The B also was fitted with a rear drawbar for draught work and a belt pulley for driving various types of barn machinery allowing owners to not only replace their horses but carry out other work either done by hand, oil engines or contractors.

From 1938 to 1941 many Model B’s were imported into the UK and after the war the Model B was produced in the UK at AC’s plant at Totton in Southampton using a larger engine and UK-sourced wheel and electrical equipment.

Production then moved to Essendine near Stamford until 1954 when it was replaced by the D270. By this time the B was fitted with hydraulics and a pan seat.

British Bs can be identified by the adjustable width front axle as opposed the US bow type.

This small size has allowed the Model B to remain popular in today’s preservation world as it is easy to store and light enough to be towed behind a family car.

It also makes an ideal entry vehicle for those wishing to become involved in vehicle preservation. The wide bench seat is another feature that endears it to enthusiasts and their partners.

There are plenty of Model Bs on the market. The big challenge with restoring and exhibiting the Model B is finding some attachments to fit to it.

Small but perfectly formed: the Model B.