Ordnance ML 4.2-inch Mortar

History

In order to keep up with the German army and its successes in the early years of World War II, the British authorities felt it necessary to replicate a heavy smoking mortar for their Royal Corps of Engineers. This created the requirement for the production of heavy field mortars, which we could also use to create the "Ordnance, ML 4.2" Mortar, to attack enemy positions with thrown explosive ordnance.

The 4.2-inch model was added to the British Army's existing stock of 2- and 3-inch infantry mortars.

The 4.2-inch mortar had a caliber of 106.7 mm, and its design largely followed the form and function of the 1915 British Stokes mortar. It was developed from the Armaments Research and Development Agency (ARDE) at the Royal Armouries Factory (RAF) late 1941.

The 4.2" officially entered front-line service in 1942, with approximately 3,800 eventually produced.

Early forms of mortars were equipped with tripods and base plates. Broadly speaking, the weapon looks like part of a traditional battlefield mortar, with the complete system utilizing a sleek launch tube, support legs, ground recoil plates and aiming/range controls.

Due to its size and weight, a crew of six is ??typical of field-deployed artillery, which is put into service behind a small tracked carrier or JEEP-style vehicle.

The gun has an elevation range of +45 to +80 degrees and allows for moderate indirect fire on enemy positions - mostly using standard high-explosive (HE) shells (but also smoke and practice rounds). The traversal is +10 degrees to either side of the center before the entire system has to be rotated in the direction of the intended shot. A well-trained and experienced crew can achieve sustained fire of up to 20 rounds a minute, compared to a typical firing range of 10 rounds per minute. The maximum attack range reaches between 3,300 and 4,400 yards, allowing the 4.2-inch mortar to control the battlefield well.

Standard HE rounds weigh about 20 pounds. However, the British defence industry reached its limits between 1941 and 1942 and was satisfied with the limited capacity "cast" bomb bodies of the expected forged type - this is reflected in the wide range of fields of use listed above.

This weapon was baptized with fire during the North African campaign during El Alamein, and mortars were released within the British "Chemical Warfare Company" until 1943 when a dedicated heavy mortar company was deployed. The weapon was in time for widespread service in subsequent European and Pacific campaigns (including service with the Australian and Canadian armies) with good results.

At the end of the war, the gun ditched the tripod and base plate in favor of the Mk 1 Mobile Base Plate Trailer - a wheeled platform that facilitated rapid transport and firing, and required only two dedicated personnel for minimal operation.

A competent 4.2" mortar design that held up well in the postwar period, it was still in use during the Korean War (1950-1953), and its indirect fire capability excelled in rough and mountainous terrain Before the history of the armies of Ethiopia, Laos, Malaysia, Nepal and Turkey were fully written, South Korea's line of weapons was also in foreign service.

Specification

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