Developed early in the war by Herbert Garland, a pre-war metallurgist and superintendent of laboratories at the Cairo Citadel, it was the most numerous mortar of the Gallipoli Campaign.

Its design meant that the whole weapon had to be turned to change its traverse and raised on a box to increase its range but despite these limitations it was reported to have done "good work" in the front line.

[1] The weapon was of straightforward construction, comprising a plain, smoothbore, tempered steel barrel of 65 mm calibre fitted at a fixed 45-degree angle to a solid wooden base.

[2][4] However the Australian War Museum holds an example of a more complex bomb with a three ounce gelignite charge and an impact detonation mechanism, mounted on a wooden shaft.

[4] General William Birdwood, commander of the Australian and New Zealand Army Corps, in correspondence with Garland, agreed to trial the mortar during the Dardanelles Campaign.