The Ordnance 4.2 inch mortar was a British designed smooth bore mortar.
It first entered British service in 1942, initially to Royal Engineer units for firing chemical weapons. Later in the war the mortar saw widespread use at divisional level, across the Army as a whole, firing conventional ammunition.
The mortar had an integrated trailer and baseplate, and the wheels could be raised for firing, or on later models, removed completely. A standard baseplate was also available.
Teams of between 2 and 6 men could operate the mortar and a range of High Explosive and Smoke rounds were available for firing.
Post war the 4.2 inch mortar entered service with Airborne Royal Artillery units, and saw extensive service from the late 1940s, before being withdrawn in the 1960s.
In the 1980s US Army M30 4.2 inch Mortars were used whilst on joint exercises in the United States.
Calibre 4.2 inch (106.7mm)
Elevation 45 to 80 degrees
Traverse 10 degrees
Range 4100 yds (3750m)
Weight 1320 ILbs (599Kg)