Smith Gun - Design

Design

The Smith Gun consisted of a 3 inch calibre smoothbore barrel 54 inches in length, which was mounted on a carriage which looked "like a two-wheeled baby carriage" and weighed approximately 604 pounds. A shield was erected between the two wheels to provide cover for the crew. The weapon had an unusual firing procedure, in which it was actually tipped over onto one wheel, this acting a baseplate and thereby allowing the Smith Gun to be rotated 360 degrees with a 40 degree elevation. It was light enough that it could be towed behind a civilian vehicle, although it was not designed for this and Home Guard units had to be prohibited from doing so as it would damage the wheels of the weapon's carriage. The Smith Gun was able to fire both anti-personnel and anti-tank rounds, with the latter capable of penetrating some 60mm of armour at that range. Fletcher claims that it had a range of approximately 500 yards, although Mackenzie states that it had an effective range of only between 100–300 yards, and was also inaccurate.

The weapon was found to have several flaws in its design, and as such was not well liked by some of the Home Guard units to which it was issued. It was heavy and awkward to manhandle, particularly over rough ground and in urban areas; in the latter, it was recommended that toggle ropes be used to manoeuvre the weapon into position. It also possessed a low muzzle velocity; and due to the initial supply of rounds possessing faulty fuzes it gained "a terrifying reputation for killing its crew."