British logistics played a key role in the success of Operation Overlord, the Allied invasion of France in June 1944. The objective of the campaign was to secure a lodgement on the mainland of Europe for further operations. The Allies had to land sufficient forces to overcome the initial opposition and build them up faster than the Germans could respond. Planning for this operation had begun in 1942. The Anglo-Canadian force, the 21st Army Group, consisted of the British Second Army and Canadian First Army. Between them, they had six armoured divisions (including the Polish 1st Armoured Division), ten infantry divisions, two airborne divisions, nine independent armoured brigades and two commando brigades. Logistical units included six supply unit headquarters, 25 Base Supply Depots (BSDs), 83 Detail Issue Depots (DIDs), 25 field bakeries, 14 field butcheries and 18 port detachments. The army group was supported over the beaches and through the Mulberry artificial port specially constructed for the purpose.
During the first seven weeks after the British and Canadian landings in Normandy on D-Day, 6 June 1944, the advance was much slower than anticipated, and the lodgement area was much smaller. The short lines of communication provided an opportunity to accumulate reserves of supplies. Two army roadheads were created. No. 1 Army Roadhead for I Corps and No. 2 Army Roadhead for XXX Corps, these being the two corps ashore at the time. When the Canadian First Army assumed control of the British I Corps on 21 June, the No. 1 Army Roadhead also passed into its control. No. 2 Army Roadhead formed the nucleus of what became the Rear Maintenance Area (RMA) of the 21st Army Group. By 26 July, 675,000 personnel, 150,000 vehicles and of stores and of bulk petrol had been landed. Ammunition usage was high, exceeding the daily allocation for the 25-pounder field guns by 8 per cent and for the 5.5-inch medium guns by 24 per cent. Greater priority was given to ammunition shipments, with petrol, oil and lubricant (POL) shipments cut to compensate.
On 25 July, the US First Army began Operation Cobra, the break-out from Normandy. On 26 August, the 21st Army Group issued orders for an advance to the north to capture Antwerp, Belgium. After a rapid advance, the British Guards Armoured Division liberated Brussels, the Belgian capital, on 3 September and the 11th Armoured Division captured Antwerp the following day. The advance was much faster than expected and the rapid increase in the length of the line of communications threw up logistical challenges that, together with increased German resistance, threatened to stall the Allied armies. By mid-September, the Allies had liberated most of France and Belgium. The success of the 21st Army Group was in large part due to its logistics, which provided the operational commanders with enormous capacity and tremendous flexibility.
Background
Between the world wars the British Army developed a doctrine based on using machinery as a substitute for manpower. In this way, it was hoped that mobility could be restored to the battlefield and the enormous casualties of the Great War could be avoided. The Army embraced motor transport and mechanisation as a means of increasing the tempo of operations. The wholesale mechanisation of the infantry and artillery was ordered in 1934 and by 1938, the British Army had only 5,200 horses, compared with 28,700 on the eve of the Great War in 1914. In the Second World War, the Army relied entirely on motor transport to move supplies between the railheads and the divisional depots.
France was occupied by Germany in June 1940 following the German victory in the Battle of France. An important factor in the defeat was the failure of the logistical system of the British Expeditionary Force, which responded too slowly to the rapid German advance. In the aftermath, the prospect of a British army invading and liberating France was remote, and the British Army concentrated on repelling rather than mounting a cross-channel attack. On 19 June 1940, the Chief of the Imperial General Staff (CIGS), General Sir John Dill, ordered that all line of communications units not required for home defence be disbanded and no further units be raised. In the event of an invasion of the UK, the Home Forces planned to rely on civilian resources for transportation, communications and maintenance. In March 1941, the War Cabinet decided that the Army had reached its maximum size. Henceforth, although the manpower "ceiling" was to be raised a little, this meant that raising more logistical units required the conversion of other units.
By this time, Home Forces divisions had a divisional slice (the personnel of the division plus the supporting operational and logistical units at corps and army level) of 25,000, but overseas operations required one of 36,500 to 39,000. The German invasion of the Soviet Union in June 1941 drew German forces away from the west, and the Japanese attack on Pearl Harbor in December 1941, while having the immediate effect of diverting troops from the war against Germany, brought the United States into the war, with the prospect of substantial resources over the longer term. This made realistic planning for an invasion of France possible. A War Office staff study in May 1942 for Operation Sledgehammer, an assault on France in 1942, revealed that an expeditionary force of six divisions would require all the logistical units in the UK, but not until 18 December 1942 was a final decision taken that a German invasion of the UK in 1943 was highly unlikely, and the reorganisation of the forces in the UK for an invasion of France could begin.
Operation Sledgehammer was superseded by Operation Roundup, a plan for an invasion of France in 1943. In January 1943, the Commander-in-Chief, Home Forces, General Sir Bernard Paget, estimated that an expeditionary force of eleven British and five Canadian divisions could be assembled by August 1943, but the diversion of resources to the Mediterranean theatre meant that by August there were only enough logistical units to support five divisions, and the full force would not be assembled until April 1944. By November 1943, the force earmarked for France had dropped to twelve British and Canadian divisions, but the Prime Minister, Winston Churchill, felt that as the Americans were contributing fifteen divisions, this should be matched. Three divisions were therefore withdrawn from the Mediterranean.
The British Army's administrative doctrine was honed in the Western Desert Campaign, where lessons were learnt and administrative staff and logistical units developed effective procedures through trial and error. Doctrine based on fighting in Europe where there was a temperate climate and well-developed road and rail infrastructure was set aside and new organisational and logistical structures such as the Field Maintenance Centre (FMC) were developed. By 1944, the skill of the British Army in the field of logistics had been brought to a high state of efficiency and support from the United States through Lend-Lease made enormous quantities of materiel available. Mechanisation and overwhelming firepower demanded a great deal from the Army's logistical infrastructure. Fortunately, the British Army had 200 years' experience of fighting campaigns far from home.
Planning A plan for a cross-channel invasion was drawn up by a staff led by the designated chief of staff to the Supreme Allied Commander (COSSAC), and approved at the Quebec Conference in August 1943. It was codenamed Operation Overlord. COSSAC also inherited and developed plans for Operation Rankin, a contingency plan for a sudden German collapse. Home Forces headquarters was divided in two in May 1943 to create an expeditionary headquarters, the 21st Army Group. From January 1944, the army group, consisting of the British Second Army and the Canadian First Army, was commanded by General Bernard Montgomery. The two armies comprised six armoured divisions (including the Polish 1st Armoured Division), ten infantry divisions, two airborne divisions, nine independent armoured brigades and two commando brigades. Although it contained personnel from many nations, the logistical support was British. There was virtually no separate Canadian supply organization other than what existed within First Canadian Army itself. The great majority of Canadian requirements were drawn from British sources.
The total strength of the British and Canadian components of the 21st Army Group was about 849,000, of which 695,000 were British Army, 107,000 were Canadian Army and 47,000 were members of the Royal Air Force (RAF) and Royal Canadian Air Force (RCAF). Of the British troops in the 21st Army Group, 56 per cent were in the combat and combat support arms, artillery, infantry, armour, engineers and signals. The 44 per cent in the services included 15 per cent in the Royal Army Service Corps (RASC), 10 per cent in the Pioneer Corps, 5 per cent in the Royal Electrical and Mechanical Engineers (REME), 4 per cent in the Royal Army Medical Corps (RAMC), Royal Army Dental Corps and Queen Alexandra's Imperial Military Nursing Service (QAIMNS) and 10 per cent in other services, such as the Royal Army Ordnance Corps (RAOC) and the Corps of Military Police (CMP).
Logistical units included six supply unit headquarters, 25 Base Supply Depots (BSDs), 83 Detail Issue Depots (DIDs), 25 field bakeries, 14 field butcheries and 18 port detachments. This was less than the planners called for, as fewer logistical units returned from the Mediterranean than anticipated. In April 1944, the RASC, the corps of the British Army responsible for most forms of supply and transport, was about 15,000 men short of its requirements. About 9,000 men were transferred from anti-aircraft units, 1,000 from Home Forces and 1,000 from units in the Middle East. This meant that they were still 4,000 men short at the end of May and this had to be accepted. Units intended for beach work received additional training at Combined Operations training centres. Eleven general transport companies were equipped with DUKWs and were trained at the RASC Amphibious Training Centre at Towyn in Wales.
The United States First Army was also assigned to the 21st Army Group for the assault phase of the campaign and although the United States Army maintained a separate supply organisation, an American brigadier general was assigned as a deputy to the Major-General Administration (MGA) of the 21st Army Group and representatives of the American G-1 and G-4 sections were attached to their opposite numbers at 21st Army Group, the A and Q staffs. The MGA, Major-General Miles Graham, had three principal subordinates: a Deputy Quartermaster General (DQMG) for plans and maintenance, Brigadier Randle (Gerry) Feilden; a DQMG for movements and transportation, Brigadier L. L. H. McKillop; and a Deputy Adjutant General (DAG), Brigadier Cyril Lloyd, responsible for personnel and administrative services.