The QF 1 pounder universally known as the pom-pom, was an early 37 mm British autocannon. It was used by several countries initially as an infantry gun and later as a light anti-aircraft gun.
It was originally designed in the late 1880s by Hiram Maxim as an enlarged version of the Maxim machine gun. Its longer range necessitated exploding projectiles to judge range, which in turn dictated a shell weight of 1 lb (in fact 400 grams), as that was the lightest exploding shell allowed under the St. Petersburg Declaration of 1868 and reaffirmed in the Hague Convention of 1899.
Early versions were sold under the Maxim-Nordenfelt label, whereas versions in British service (i.e. from 1900) were labelled Vickers, Sons and Maxim (VSM) as Vickers had bought out Maxim-Nordenfelt in 1897. They are all effectively the same gun.
Second Boer War
Australian troopers with 1 pounder in South Africa circa. 1901
Boer 1 pounder with shield
The British government initially rejected the gun but other countries bought it, including the South African Republic (Transvaal) government. In the Second Boer War, the British found themselves being fired on with success by the Boers with their 37 mm Maxim-Nordenfelt versions with ammunition made in Germany.
In response, Vickers-Maxim of Britain shipped either 57 or 50 guns out to the British Army in South Africa, with the first three arriving in time for the Battle of Paardeberg of February 1900These early Mk I versions were mounted on typical field gun type carriages.
World War I
In World War I, it was used as an early anti-aircraft gun in the home defence of Britain. It was adapted as the Mk I+++ and Mk II on high-angle pedestal mountings and deployed along London docks and on rooftops on key buildings in London, others on mobile motor lorries at key towns in the East and Southeast of England. 25 were employed in August 1914, and 50 in February 1916. The Mk II gun at the top of this page on Naval pedestal mounting was the first to open fire in defence of London during the war. However, the small shell was insufficient to damage the German Zeppelin airships sufficiently to bring them down. The Ministry of Munitions noted in 1922: "The pom-poms were of very little value. There was no shrapnel available for them, and the shell provided for them would not burst on aeroplane fabric but fell back to earth as solid projectiles... were of no use except at a much lower elevation than a Zeppelin attacking London was likely to keep".
Nevertheless, Lieutenant O.F.J. Hogg of No. 2 AA Section in III Corps was the first anti-aircraft gunner to shoot down an aircraft, with 75 rounds on 23 September 1914 in France.
The British Army did not employ it as an infantry weapon in World War I, as its shell was considered too small for use against any objects or fortifications and British doctrine relied on shrapnel fired by QF 13 pounder and 18-pounder field guns as its primary medium range anti-personnel weapon.
The gun was tried with only limited success mounted on aircraft as the lighter 1-pounder Mk III, and was quickly replaced by the larger QF 1½ pounder and QF 2 pounder naval guns as a light anti-aircraft gun.
The British are reported to have initially used some Common pointed shells (semi-armour piercing, with fuze in the shell base) in the Boer War, in addition to the standard Common shell. However, the common pointed shell proved unsatisfactory, with the base fuze frequently working loose and falling out during flight. In 1914 the cast-iron Common shell and tracer were the only available rounds.