M4 tractor


The M4 high-speed tractor for World War II was an artillery tractor used by the US Army from 1943.

Design and development

The M4 high-speed tractor used M4 Sherman tracks, roadwheels, and drive sprocket. However, the suspension was of the Horizontal Volute Spring Suspension type, first introduced on a light tank T6 project in 1938.
One variant was designed to tow the 90 mm anti-aircraft gun, and another was for the 155 mm gun or 8-inch howitzer. The rear compartment carried the gun crew and other equipment and some later variants included a crane to assist with heavier projectiles. Two types of ammunition boxes were used on all models: a 90 mm box with side "tailgates" to access 90 mm shells pigeon-holed in the sides, and a combination box for 155 mm or 8-inch ammunition.

History

The M4 was built by tractor manufacturer Allis-Chalmers of West Allis, Wisconsin, starting in 1943 and was in U.S. military service until approximately 1960. After WWII, under the US Mutual Defense Assistance Program, M4s were supplied to Greece, the Netherlands, Japan, Brazil, Yugoslavia and Pakistan and several other states friendly to the USA. In the Indo-Pakistani War of 1965, the Pakistani Army used M4 tractors to haul their M115 howitzers to the battlefield of Chamb and then to the front at Lahore during the fighting with Indian troops.

Variants

  • M4: base model. 2,464 were configured to tow the 90 mm antiaircraft gun, while 3,088 were configured to tow the 155 mm gun or 8-inch howitzer
  • M4C: The "C" designation indicates spare ammunition racks configured in the crew compartment.
  • M4A1: The "A1" modification designates the wider suspension used for the "duck bill" tracks mirroring the E9 modification on Sherman tanks. 259 were built in 1945, and were used post-war as a prime mover for the M23 ammunition trailer in M40 gun motor carriage sections.

    Civilian use

After the war many types of these tractors were stripped of their military components and used for log skidders and power line construction. Many were used as carriers for rock drills, used in logging road construction in British Columbia. The first prototype was designed in the early 1960s by G.M. Philpott Ltd. of Vancouver, BC, and Scott-Douglas Industries, who supplied the M4 Carrier. It was used by MacMillan, Bloedel, and Powell River Company at their Juskatla, BC logging operation. Many improvements were made and when Finning Tractor later bought G.M. Philpott, the machine became the Finning Tank Drill. At least 500 were built, many of which are still in service. The original Finning Tank Drill was replaced by the M32F and M40F Tank Drills, which used larger Sherman tank carriers.
At Amsterdam Airport Schiphol in the Netherlands, at least two refurbished M4s were used by the airport fire brigade in the 1960s and '70s. During the mid-80s and into the early 90s, many M-4s were converted into exhibition vehicles used for car crushing and dubbed "monster tanks", William Townes's "Virginia Beach Beast" Chevrolet K-5 Blazer being among the first.

Surviving vehicles