Although the usefulness of the machine gun had not been fully appreciated by the British Army before the outbreak of WWI, it soon became apparent that highly-mobile machine gun units would be of considerable value in the fluid warfare that characterized the first few weeks of the war. The formation of batteries of motorcycle-mounted machine guns was authorized in 1914. These batteries were designated part of the Royal Field Artillery, one battery being allocated to the divisional Artillery of each Division of the British Expeditionary Force. Each battery consisted of 18 motorcycle/sidecar combinations, carrying six Vickers machine guns, ammunition and spare parts, eight motorcycles without sidecars, and two or three cars or trucks. Members were recruited from Motor Cycle Clubs and officers seconded from other regiments. In 1915, as the war bogged down in the stalemate of trench warfare, the mobility of these batteries became of lesser importance, and the service was incorporated into the Motor Machine Gun Service (MMGS) as the Machine Gun Corps (MGS).(Motors).