The M9 served for a considerable period of time during the second world war and beyond.
The concept of a combined wheeled and tracked vehicle dates back to the 1910s, but it was not until the Second World War that the vehicle became extremely popular. One of the proven successful stars was the M9 half-track produced by International Harvester of the United States. The M9 was a vehicle with the excellent cross-country ability of a tracked vehicle combined with the handling of a wheeled vehicle.
The M9 served for a considerable period of time during the second world war and beyond. Three thousand five-hundred were produced by the end of World War II. It was used during World War II, the Arab-Israeli War of 1948, the Korean War, the Suez Crisis, the Vietnam War, the Six-Day War, and the Yom Kippur War. It had been used by eleven different countries by the end of its service.
The M9 was produced between 1942–1944, using the same chassis and mechanical components as the M5. The result was a vehicle with a truck-like front section and a tank-like rear that showcased the track-and-wheel system. The vehicle had a weight of about 9.3 short tons, a length of 6.28 m, a width of 2.22 m, and a height of 2.26 m. The standard operating crew was usually three with seating for ten in the rear section.
The rear part of the vehicle was designed to be open, providing only protection against light fire. It could be used to transport goods or combat-ready infantry. Weapons could be equipped for self-defense, consisting of a single 12.7mm heavy machine gun and 2 x 7.62mm machine guns could be added on pintle mounts depending on mission requirements. Powering the vehicle was an IHC RED-450-B engine with 141 horsepower, for a maximum speed of up to 68 km/h.
A variant of the M9 was the M9A1 with the changes being a ring machine gun mount and three pintle machine gun mounts. The production of M9s was leased to other countries, both the Soviet Union and the United Kingdom, with the latter providing it to other countries in the British Commonwealth. Following World War II, the second-hand market was a source of supply for some countries, including Israel.