The Ordnance ML 4.2-inch mortar was a heavy
mortar used by the British Army during and after World War II.
History
The mortar was a smooth-bore weapon of the
Stokes pattern and was designed by the
Armaments Research and Development Establishment
Fort Halstead was a research site of Dstl, an executive agency of the UK Ministry of Defence. It is situated on the crest of the Kentish North Downs, overlooking the town of Sevenoaks, southeast of London. Originally constructed in 1892 as part ...
and produced by the
Royal Ordnance Factories
Royal Ordnance Factories (ROFs) was the collective name of the UK government's munitions factories during and after the Second World War. Until privatisation, in 1987, they were the responsibility of the Ministry of Supply, and later the Minist ...
.
[Pugh p. 76] It entered widespread British service in 1942, equipping chemical warfare companies of the
Royal Engineers (RE). The Mark 3 became the standard model.
The first combat use was at
Second Battle of El Alamein
The Second Battle of El Alamein (23 October – 11 November 1942) was a battle of the Second World War that took place near the Egyptian railway halt of El Alamein. The First Battle of El Alamein and the Battle of Alam el Halfa had prevented th ...
, when the 66th Mortar Company (RE) was attached to the
Australian 24th Infantry Brigade. During the battle, 66 Mortar Company provided intense, effective supporting fire on the 24th Brigade's exposed right flank, as the infantry advanced, expending all of the 4.2-inch HE mortar ammunition in the theatre.
Around mid-1943, the Royal Engineer chemical warfare companies were disbanded as an emergency expedient and one heavy mortar company of each infantry division machine-gun battalion was equipped with the mortar. This company was organized with sixteen 4.2-inch mortars, in four platoons of four mortars each. In early 1944, divisions in Italy also held a pool of mortars for issue to other units as needed, usually troops in the divisional anti-tank regiment, some regiments even converted one or more batteries to mortars.
Ordnance ML 4.2-inch mortars were slower to reach Commonwealth forces in the
Pacific and Asia. Australian Army units in the
South West Pacific theatre
The South West Pacific theatre, during World War II, was a major theatre of the war between the Allies and the Axis. It included the Philippines, the Dutch East Indies (except for Sumatra), Borneo, Australia and its mandate Territory of ...
were reportedly the first to receive them, before forces in
Burma
Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John Wells explai ...
.
Postwar
After World War II, the mortars were handed over to the
Royal Artillery
The Royal Regiment of Artillery, commonly referred to as the Royal Artillery (RA) and colloquially known as "The Gunners", is one of two regiments that make up the artillery arm of the British Army. The Royal Regiment of Artillery comprises t ...
, the 170th Mortar Battery used them at the
Battle of Imjin River
The Battle of the Imjin River ( fil, Labanan sa Ilog Imjin), also known as the Battle of Solma-ri ( ko, 설마리 전투) or Battle of Gloster Hill () in South Korea, or as Battle of Xuemali () in China, took place 22–25 April 1951 during the ...
in Korea. They were used during the 1950s, also by airborne artillery, deployed to
Kuwait
Kuwait (; ar, الكويت ', or ), officially the State of Kuwait ( ar, دولة الكويت '), is a country in Western Asia. It is situated in the northern edge of Eastern Arabia at the tip of the Persian Gulf, bordering Iraq to the nort ...
in 1961 and manned by soldiers from air defence batteries during the Confrontation in Borneo in 1965.
Description
The 4.2-inch mortar entered production at the end of 1941 with a standard base plate and tripod. The normal detachment was six men and it was transported with ammunition in a 10
cwt trailer, usually towed behind a
Loyd Carrier
The Loyd Carrier was one of a number of small tracked vehicles used by the British and Commonwealth forces in the Second World War to transport equipment and men about the battlefield. Alongside the Bren, Scout and Machine Gun Carriers, they ...
. There was also an auxiliary base plate that fitted around it, to increase its area for use on softer ground. Later an integrated trailer/base plate was developed, called the Mk 1 Mobile Baseplate. The wheels, which were on suspension arms, were unlocked and raised for firing; the Mk1/1 had detachable wheels and the barrel with tripod attached, was stowed on top for towing. The mobile base plate trailer mounting could be brought into action by 2 men.
Regarding rate of fire, one source reports a crew putting 23 bombs in the air before the first impacted.
Ammunition
Both HE (9.1 kg) and smoke (10.2 kg) ammunition was used. Smoke included WP and Base Ejection, and in World War II other types for practice. Two charges were available. In World War II, both streamlined and cylindrical bombs were available. Chemical munitions included the MK I chemical mortar bomb with
Mustard gas (HS or HT fillings).
Users
World War II
*
*
[https://nzetc.victoria.ac.nz/tm/scholarly/tei-WH2Arti-c18-1.html]
*
Postwar
*
*
*
*
*
*
*
*
*
*
*
Gallery
The British Army in North-west Europe 1944-45 B10448.jpg
The British Army in Sicily 1943 NA5666.jpg
The British Army in Burma 1945 SE4463.jpg
The British Army in Italy 1944 NA13049.jpg
The British Army in Italy 1944 NA12884.jpg
See also
Weapons of comparable role, performance and era
*
M2 4.2 inch mortar – US equivalent
*
107mm M1938 mortar
The Soviet 107mm M1938 mortar was a scaled-down version of the 120mm M1938 mortar intended for use by mountain troops and light enough to be towed by animals on a cart.
History
In World War II, the 107mm mortar saw service with Soviet mountain in ...
– Soviet equivalent
Notes
References
*
*
*
* Maintenance Manual for ML 2-inch, ML 3-inch and SB 4.2-inch mortars
*
*
External links
*
{{BritishEmpireWeapons
Mortars of the United Kingdom
World War II infantry mortars of the United Kingdom
107 mm artillery
United Kingdom chemical weapons program
Chemical weapon delivery systems
Weapons and ammunition introduced in 1942