World War II Database

Contributor: C. Peter Chen

The Ordnance SBML 2-inch light mortars were developed in the mid-1930s, with the design's foundation based on a license of a 50-millimeter mortar design by the firm Esperanza y Cia of Spain. Ten examples were built for trials in Nov 1937, along with 1,600 rounds of high explosive shells and 1,600 rounds of smoke shells. In Feb 1938, the trials were deemed successful, and an order for mass production was given. Typically, they were each operated by a crew of two, with one man holding and aiming the barrel, while the other dropping the shells into the barrel. By 1939 when the European War of WW2 began, about 500 of them were in service with the British Army. These weapons of the initial variant were designated as Mk II despite being the first variant of the design; the designation Mk I was used by a unrelated WW1-era launcher of similar caiber. These weapons' greatest advantages were their operational simplicity (painted white lines to indicate firing direction, rather than the use of sights) and their light weight (no bipods; curved base plates). Several different variants were produced, including short-barreled variants for airborne use and variants designed specifically for mounting on vehicles. They typically fired 1.02-kilogram high explosive shells, but they could also employ a wide range of alternate ammunition, including smoke shells, illuminating shells, and the atypical shells that could cast net filled with explosives meant to detonate mines in suspected enemy minefields. They were used widely by British and Commonwealth units during WW2, and many saw action in the subsequent Korean War. After the Korean War, they remained in British service as launchers for smoke and illuminating shells until the 1980s. Indian Army's 51-millimeter E1 mortars, still in production and still in operation at the time of this writing, were developed from the Ordnance SBML 2-inch mortar design.

Ordnance SBML 2-inch Mortar Launcher Interactive Map

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