Combined Bomber Offensive
Encyclopedia
The Combined Bomber Offensive (CBO) was an Anglo-American offensive of strategic bombing during World War II
in Europe. The primary portion of the CBO was against German Air Force targets which was the highest priority from June 1943 to 1944. The subsequent highest priority campaigns were against V-weapon installations (June 1944) and petroleum, oil, and lubrication (POL) plants
(September 1944). Additional CBO targets included railyards and other transportation targets, particularly prior to the invasion of Normandy and, along with army equipment, at the in the final stages of the War in Europe
.
The British bombing campaign was chiefly waged by night by large numbers of heavy bombers until the latter stages of the war when German fighter defences were so reduced that daylight bombing was possible without risking large losses. The US effort was by day - massed formations of bombers with escorting fighters. Together they made up a round-the-clock bombing effort except where weather conditions prevented operations.
) had drawn up their plans for attacking the Axis powers.
After the British Ministry of Economic Warfare (MEW) published the "Bombers' Baedeker" in 1942 that identified the "bottleneck" German industries of oil, communications, and ball bearings, the Combined Chiefs of Staff
agreed at the January 1943 Casablanca Conference to conduct the "Bomber Offensive from the United Kingdom" with the "Casablanca directive
" stating the objective as :
After initiating the preparation of a U.S. targeting plan on December 9, 1942; on March 24, 1943, General "Hap" Arnold
, the USAAF Commander requested target information from the British,:
and the "Report of Committee of Operations Analysts" was submitted to Arnold on March 8, 1943 and then to the Eighth Air Force commander as well as the British Air Ministry
, the MEW, and the RAF commander. The COA report recommended 18 operations during each three-month phase (12 in each phase were expected to be successful) against a total of 76 specific targets. Using the COA report and information from the M.E.W., in April 1943 an Anglo-American committee (composed of British Chiefs of Staff and the U.S. Joint Chiefs of Staff) under Lieutenant General Ira C. Eaker; led by Brigadier General Haywood S. Hansell
, Jr.; and including Brig. Gen. Orvil A. Anderson completed a plan for the "Combined Bomber Offensive from the United Kingdom", which projected the US bomber strength for the four phases (944, 1192, 1746, & 2702 bombers) through 31 March 1944. Eaker added a summary and final changes such as: "If the growth of the German fighter strength is not arrested quickly, it may become literally impossible to carry out the destruction planned" ("Intermediate Objectives" section).
, Pointblank operations against the "intermediate objective" began on 14 June, and the "Effects of Bombing Offensive on German War Effort" (J.I.C. (43) 294) by the Joint Intelligence Subcommittee was issued 22 July 1943.
Losses during the first months of Pointblank operations and lower-than-planned U.S. bomber production resulted in Portal
complaining about the 3 month CBO delay at the Cairo Conference
, where the British refused a U.S. request to place the CBO under a "single Allied strategic air commander." After Arnold submitted the October 9, 1943 "Plan to Assure the Most Effective Exploitation of the Combined Bomber Offensive" on October 22 the "Allied Joint Chiefs of Staff" signed orders to raid "the aircraft industries in the southern Germany and Austria regions".
July 1943 was the first time that the USAAF would coordinate a raid on the same location as the RAF. They were to fly two daylight missions against industrial targets (U-boat pens and yards) following the opening raid of the RAF campaign against Hamburg. However smoke from the effects of the night's bombing obscured the targets.
In October 1943 Air Chief Marshal
Arthur Harris
, C-in-C of RAF Bomber Command
urged the UK government to be honest to the public regarding the purpose of the bombing campaign and openly announce that:
On February 13, 1944, the CCS issued a new plan for the "Bomber Offensive", which no longer included German morale in the objective: "The subject of morale had been dropped and [the number of cities with targets] gave me a wide range of choice. … the new instructions therefore made no difference" to RAF Bomber Command operations (Arthur Harris
). The February 13 plan was given the code name "Argument", and after the weather became favorable on February 19, Argument operations were conducted during Big Week
(February 20–25). Harris claimed the Argument plan was not "a reasonable operation of war", and the Air Staff had to order Harris to bomb the Pointblank targets at Schweinfurt.
air plan" which omitted the requirement "to seek air superiority before the landings were attempted." Instead, the plan was to bomb communications targets (primary) and rail yards and repair facilities (secondary). Air Marshal Trafford Leigh-Mallory
, who would command the tactical element of the invasion air forces
had been assigned the responsibility on June 26, 1943, for drafting the plan, and at the February 14, 1944, meeting regarding the Overlord air plan, he claimed German fighters would defend and be defeated during the attacks on rail yards, and if not, air superiority would instead be won over the D-Day beaches. Harris rebutted that even after the planned rail attacks, German rail traffic would be sufficient to supply invasion defenses; and Spaatz proposed attacks on industry in Germany to require fighters to be moved away from the Overlord beaches to defend the plants. Tedder concluded that a committee needed to study the pre-Overlord targeting, but when the committee met in March, no consensus was reached.
On March 25, 1944 Portal chaired a meeting of the generals and restated the Pointblank objective of air superiority was still the highest CBO priority. Although the "Joint Chiefs of Staff" had previously argued that it was impossible to impede German military rail traffic due to the large reserve capacity, for the secondary priority Portal identified that pre-invasion railyard attacks only needed to reduce traffic so tactical airpower could inhibit enemy defenses during the first 5 weeks of OVERLORD. Sir John Kennedy and Andrew Noble countered that the military fraction of rail traffic was so small that no amount of railyard bombing would significantly impact operations. As endorsed on March 6 by the M.E.W. and the U.S. Mission for Economic Affairs, Spaatz again proposed that "execution of the oil plan would force the enemy to reduce oil consumption … and … fighting power" during Overlord. Although "concerned that military transportation experts of the British Army had not been consulted" about the Transportation Plan, Eisenhower decided that "apart from the attack on the GAF [German Air Force] the transportation plan was the only one which offered a reasonable chance of the air forces making an important contribution to the land battle during the first vital weeks of Overlord". Control of all air operations was transferred to Eisenhower on April 14 at noon.
However, after "very few German fighters rose to contest the early attacks on French rail yards" and the Ninth (tactical) AAF in England had dropped 33,000 tons of bombs through April on French railway targets, Churchill wrote to Roosevelt in May 1944 that he was not "convinced of the wisdom of this plan" Although Tedder's original Overlord air directive in mid-April listed no oil targets
, Eisenhower permitted Spaatz to test that the Luftwaffe would defend oil targets more heavily. During the trial raids of May 12 and May 28, German fighters heavily defended the oil targets, and after the invasion hadn't begun during the good weather of May, Luftwaffe fighters in France were recalled to defend Reich industry. The German plan was to await the invasion and then, "on the cue words 'Threatening Danger West'," redeploy fighter strength back to unused French air bases when needed against the invasion. The last two Jagdgeschwader 26
Fw 190As, piloted by Josef Priller
and his wingman, that were to be recalled conducted the only Luftwaffe day sorties over the Normandy beaches on D-day, and on June 7/8 the Luftwaffe began redeploying aircraft to France for attacking the Normandy bridgehead.
Pointblank operations ended on the fifth day of the Invasion. and the highest priority of the Combined Bomber Offensive became operations against the German rocket weapons
in June 1944 and the Oil Campaign
in September. Tedder's proposal to keep oil targets as the highest priority and place "Germany's rail system in second priority" was appproved by the CSTC on November 1. On April 12, 1945, Strategic Bombing Directive No. 4 ended the strategic bombing campaign in Europe.
Strategic bombing during World War II
Strategic bombing during World War II is a term which refers to all aerial bombardment of a strategic nature between 1939 and 1945 involving any nations engaged in World War II...
in Europe. The primary portion of the CBO was against German Air Force targets which was the highest priority from June 1943 to 1944. The subsequent highest priority campaigns were against V-weapon installations (June 1944) and petroleum, oil, and lubrication (POL) plants
Oil Campaign chronology of World War II
The Oil Campaign chronology of World War II lists bombing missions and related events regarding the petroleum/oil/lubrication facilities that supplied Nazi Germany.-Legend:...
(September 1944). Additional CBO targets included railyards and other transportation targets, particularly prior to the invasion of Normandy and, along with army equipment, at the in the final stages of the War in Europe
End of World War II in Europe
The final battles of the European Theatre of World War II as well as the German surrender to the Western Allies and the Soviet Union took place in late April and early May 1945.-Timeline of surrenders and deaths:...
.
The British bombing campaign was chiefly waged by night by large numbers of heavy bombers until the latter stages of the war when German fighter defences were so reduced that daylight bombing was possible without risking large losses. The US effort was by day - massed formations of bombers with escorting fighters. Together they made up a round-the-clock bombing effort except where weather conditions prevented operations.
Initial planning
Both the British and the US (through the Air War Plans DivisionAir War Plans Division
The Air War Plans Division was an American military organization established to make long-term plans for war. Headed by Harold L. George, the unit was tasked in July 1941 to provide President Franklin D...
) had drawn up their plans for attacking the Axis powers.
After the British Ministry of Economic Warfare (MEW) published the "Bombers' Baedeker" in 1942 that identified the "bottleneck" German industries of oil, communications, and ball bearings, the Combined Chiefs of Staff
Combined Chiefs of Staff
The Combined Chiefs of Staff was the supreme military command for the western Allies during World War II. It was a body constituted from the British Chiefs of Staff Committee and the American Joint Chiefs of Staff....
agreed at the January 1943 Casablanca Conference to conduct the "Bomber Offensive from the United Kingdom" with the "Casablanca directive
Casablanca directive
The Casablanca directive was approved by the Combined Chiefs of Staff of the Western Allies at their 65th meeting on 21 January 1943 and issued to the appropriate the Royal Air Force and United States Army Air Force commanders on 4 February 1943....
" stating the objective as :
- "The progressive destruction and dislocation of the German military, industrial and economic systems and the undermining of the morale of the German peopleArea bombing directiveThe Area Bombing Directive was a directive from the wartime British Government's Air Ministry to the Royal Air Force which ordered RAF bombers to attack the German industrial workforce and the morale of the German populace through bombing German cities and their civilian inhabitants.- Background...
to a point where their capacity for armed resistance is fatally weakened. Every opportunity to be taken to attack Germany by day to destroy objectives that are unsuitable for night attack, to sustain continuous pressure on German morale, to impose heavy losses on German day fighter force and to conserve German fighter force away from the Russian and Mediterranean theatres of war".
After initiating the preparation of a U.S. targeting plan on December 9, 1942; on March 24, 1943, General "Hap" Arnold
Henry H. Arnold
Henry Harley "Hap" Arnold was an American general officer holding the grades of General of the Army and later General of the Air Force. Arnold was an aviation pioneer, Chief of the Air Corps , Commanding General of the U.S...
, the USAAF Commander requested target information from the British,:
- (quoted by AAFRH-3, p. vii)
- (cited by AAFRH-10, p. 212)
- (quoted by Mets note 51, pp. 191,383)
- (the letter "included a report by Arnold's operations analysts about strategic targets in Europe" (Coffey, p. 203-4) and was delivered by Col. C. P. Cabell, "It was … a week before he took the letter to Portal, along with one signed by General Eaker" (Coffey, p. 205):
- cover letter: (quoted by Coffey, p. 206)
- (quoted by Coffey, p. 237)
- (identified in AAFRH-10, p. 82)
- (identified in AAFRH-10, p. 86)
and the "Report of Committee of Operations Analysts" was submitted to Arnold on March 8, 1943 and then to the Eighth Air Force commander as well as the British Air Ministry
Air Ministry
The Air Ministry was a department of the British Government with the responsibility of managing the affairs of the Royal Air Force, that existed from 1918 to 1964...
, the MEW, and the RAF commander. The COA report recommended 18 operations during each three-month phase (12 in each phase were expected to be successful) against a total of 76 specific targets. Using the COA report and information from the M.E.W., in April 1943 an Anglo-American committee (composed of British Chiefs of Staff and the U.S. Joint Chiefs of Staff) under Lieutenant General Ira C. Eaker; led by Brigadier General Haywood S. Hansell
Haywood S. Hansell
Haywood Shepherd Hansell Jr., was a general officer in the United States Army Air Forces during World War II, and later the United States Air Force...
, Jr.; and including Brig. Gen. Orvil A. Anderson completed a plan for the "Combined Bomber Offensive from the United Kingdom", which projected the US bomber strength for the four phases (944, 1192, 1746, & 2702 bombers) through 31 March 1944. Eaker added a summary and final changes such as: "If the growth of the German fighter strength is not arrested quickly, it may become literally impossible to carry out the destruction planned" ("Intermediate Objectives" section).
CBO Plan
Eaker's "Combined Bomber Offensive Plan" was "a document devised to help Arnold get more planes and men for the 8th Air Force" and not "designed to affect British operations in any substantive way." While the CBO Plan was being developed, the British independently drew up a plan in April 1943 titled "The Attack on the GAF" which envisaged attacks on airfields and aircraft factories and, in the case of the latter, may have influenced targets selection by the Eighth AF. The Combined Chiefs of Staff approved the "Eaker Plan" on May 19, 1943, and identified 6 specific "target systems" such as the German aircraft industry (including fighter strength):- 1. Intermediate objectives
- German fighter strength
- 2. Primary objectives:
- German submarine yards and bases
- The remainder of the German aircraft industry
- Ball bearings
- Oil (contingent upon attacks against Ploesti)
- 3. Secondary objectives:
- Synthetic rubber and tires
- Military motor transport vehicles
| 1942 December 9 onwards | US Committee of Operations Analysts |
| 1943 | Combined Operational Planning Committee |
| 1943 July 21 | Joint CROSSBOW Operation Crossbow Crossbow was the code name of the World War II campaign of Anglo-American "operations against all phases of the German long-range weapons programme—operations against research and development of the weapons, their manufacture, transportation and their launching sites, and against missiles in flight"... Target Priorities Committee |
| 1944 July 7 | Joint Oil Targets Oil Campaign of World War II The Allied Oil Campaign of World War II was directed at facilities supplying Nazi Germany with petroleum, oil, and lubrication products... Committee |
| 1944 October | Combined Strategic Targets Committee |
Beginning of operations
The Combined Bomber Offensive began on 10 June 1943 during the Battle of the RuhrBattle of the Ruhr
The Battle of the Ruhr was a 5-month long campaign of strategic bombing during the Second World War against the Nazi Germany Ruhr Area, which had coke plants, steelworks, and 10 synthetic oil plants...
, Pointblank operations against the "intermediate objective" began on 14 June, and the "Effects of Bombing Offensive on German War Effort" (J.I.C. (43) 294) by the Joint Intelligence Subcommittee was issued 22 July 1943.
Losses during the first months of Pointblank operations and lower-than-planned U.S. bomber production resulted in Portal
Charles Portal, 1st Viscount Portal of Hungerford
Marshal of the Royal Air Force Charles Frederick Algernon Portal, 1st Viscount Portal of Hungerford KG GCB OM DSO & Bar MC was a senior Royal Air Force officer and an advocate of strategic bombing...
complaining about the 3 month CBO delay at the Cairo Conference
Cairo Conference
The Cairo Conference of November 22–26, 1943, held in Cairo, Egypt, addressed the Allied position against Japan during World War II and made decisions about postwar Asia...
, where the British refused a U.S. request to place the CBO under a "single Allied strategic air commander." After Arnold submitted the October 9, 1943 "Plan to Assure the Most Effective Exploitation of the Combined Bomber Offensive" on October 22 the "Allied Joint Chiefs of Staff" signed orders to raid "the aircraft industries in the southern Germany and Austria regions".
July 1943 was the first time that the USAAF would coordinate a raid on the same location as the RAF. They were to fly two daylight missions against industrial targets (U-boat pens and yards) following the opening raid of the RAF campaign against Hamburg. However smoke from the effects of the night's bombing obscured the targets.
In October 1943 Air Chief Marshal
Air Chief Marshal
Air chief marshal is a senior 4-star air-officer rank which originated in and continues to be used by the Royal Air Force...
Arthur Harris
Sir Arthur Harris, 1st Baronet
Marshal of the Royal Air Force Sir Arthur Travers Harris, 1st Baronet GCB OBE AFC , commonly known as "Bomber" Harris by the press, and often within the RAF as "Butcher" Harris, was Air Officer Commanding-in-Chief of RAF Bomber Command during the latter half of World War...
, C-in-C of RAF Bomber Command
RAF Bomber Command
RAF Bomber Command controlled the RAF's bomber forces from 1936 to 1968. During World War II the command destroyed a significant proportion of Nazi Germany's industries and many German cities, and in the 1960s stood at the peak of its postwar military power with the V bombers and a supplemental...
urged the UK government to be honest to the public regarding the purpose of the bombing campaign and openly announce that:
- "the aim of the Combined Bomber Offensive...should be unambiguously stated [as] the destruction of German cities, the killing of German workers, and the disruption of civilized life throughout Germany.
- It should be emphasized that the destruction of houses, public utilities, transport and lives, the creation of a refugee problem on an unprecedented scale, and the breakdown of morale both at home and at the battle fronts by fear of extended and intensified bombing, are accepted and intended aims of our bombing policy. They are not by-products of attempts to hit factories."
On February 13, 1944, the CCS issued a new plan for the "Bomber Offensive", which no longer included German morale in the objective: "The subject of morale had been dropped and [the number of cities with targets] gave me a wide range of choice. … the new instructions therefore made no difference" to RAF Bomber Command operations (Arthur Harris
Sir Arthur Harris, 1st Baronet
Marshal of the Royal Air Force Sir Arthur Travers Harris, 1st Baronet GCB OBE AFC , commonly known as "Bomber" Harris by the press, and often within the RAF as "Butcher" Harris, was Air Officer Commanding-in-Chief of RAF Bomber Command during the latter half of World War...
). The February 13 plan was given the code name "Argument", and after the weather became favorable on February 19, Argument operations were conducted during Big Week
Big Week
Between February 20–25, 1944, as part of the European strategic bombing campaign, the United States Strategic Air Forces launched Operation Argument, a series of missions against the Third Reich that became known as Big Week. The planners intended to lure the Luftwaffe into a decisive battle by...
(February 20–25). Harris claimed the Argument plan was not "a reasonable operation of war", and the Air Staff had to order Harris to bomb the Pointblank targets at Schweinfurt.
Overlord air plan
During the "winter campaign against the German aircraft industry … January 11 [-] February 22, 1944", review began on the initial "OverlordOperation Overlord
Operation Overlord was the code name for the Battle of Normandy, the operation that launched the invasion of German-occupied western Europe during World War II by Allied forces. The operation commenced on 6 June 1944 with the Normandy landings...
air plan" which omitted the requirement "to seek air superiority before the landings were attempted." Instead, the plan was to bomb communications targets (primary) and rail yards and repair facilities (secondary). Air Marshal Trafford Leigh-Mallory
Trafford Leigh-Mallory
Air Chief Marshal Sir Trafford Leigh-Mallory KCB, DSO & Bar was a senior commander in the Royal Air Force. Leigh-Mallory served as a Royal Flying Corps pilot and squadron commander during World War I...
, who would command the tactical element of the invasion air forces
Allied Expeditionary Air Force
The Allied Expeditionary Air Force was a component of the Supreme Headquarters Allied Expeditionary Force which controlled the tactical air power of the Allied forces during Operation Overlord.Its effectiveness was less than optimal on two counts...
had been assigned the responsibility on June 26, 1943, for drafting the plan, and at the February 14, 1944, meeting regarding the Overlord air plan, he claimed German fighters would defend and be defeated during the attacks on rail yards, and if not, air superiority would instead be won over the D-Day beaches. Harris rebutted that even after the planned rail attacks, German rail traffic would be sufficient to supply invasion defenses; and Spaatz proposed attacks on industry in Germany to require fighters to be moved away from the Overlord beaches to defend the plants. Tedder concluded that a committee needed to study the pre-Overlord targeting, but when the committee met in March, no consensus was reached.
On March 25, 1944 Portal chaired a meeting of the generals and restated the Pointblank objective of air superiority was still the highest CBO priority. Although the "Joint Chiefs of Staff" had previously argued that it was impossible to impede German military rail traffic due to the large reserve capacity, for the secondary priority Portal identified that pre-invasion railyard attacks only needed to reduce traffic so tactical airpower could inhibit enemy defenses during the first 5 weeks of OVERLORD. Sir John Kennedy and Andrew Noble countered that the military fraction of rail traffic was so small that no amount of railyard bombing would significantly impact operations. As endorsed on March 6 by the M.E.W. and the U.S. Mission for Economic Affairs, Spaatz again proposed that "execution of the oil plan would force the enemy to reduce oil consumption … and … fighting power" during Overlord. Although "concerned that military transportation experts of the British Army had not been consulted" about the Transportation Plan, Eisenhower decided that "apart from the attack on the GAF [German Air Force] the transportation plan was the only one which offered a reasonable chance of the air forces making an important contribution to the land battle during the first vital weeks of Overlord". Control of all air operations was transferred to Eisenhower on April 14 at noon.
However, after "very few German fighters rose to contest the early attacks on French rail yards" and the Ninth (tactical) AAF in England had dropped 33,000 tons of bombs through April on French railway targets, Churchill wrote to Roosevelt in May 1944 that he was not "convinced of the wisdom of this plan" Although Tedder's original Overlord air directive in mid-April listed no oil targets
Oil Campaign targets of World War II
Allied bombing of the Oil Campaign targets of World War II included attacks on Nazi Germany oil refineries, synthetic oil plants, storage depots, and other chemical works. Natural oil was available in Northwestern Germany at Nienhagen , Rietberg , and Heide and refineries were mainly at Hamburg...
, Eisenhower permitted Spaatz to test that the Luftwaffe would defend oil targets more heavily. During the trial raids of May 12 and May 28, German fighters heavily defended the oil targets, and after the invasion hadn't begun during the good weather of May, Luftwaffe fighters in France were recalled to defend Reich industry. The German plan was to await the invasion and then, "on the cue words 'Threatening Danger West'," redeploy fighter strength back to unused French air bases when needed against the invasion. The last two Jagdgeschwader 26
Jagdgeschwader 26
Jagdgeschwader 26 Schlageter was a Luftwaffe fighter-wing of World War II. It operated mainly in Western Europe against Great Britain, France the United States but also saw service against Russia. It was named after Albert Leo Schlageter, a World War I veteran and Freikorps member arrested and...
Fw 190As, piloted by Josef Priller
Josef Priller
Josef "Pips" Priller was a German World War II fighter ace. He has become famous because of the publicity regarding his Focke-Wulf's Fw 190A-8's single strafing pass attack on Sword Beach on June 6, 1944 , accompanied by his wingman Herbert Huppertz...
and his wingman, that were to be recalled conducted the only Luftwaffe day sorties over the Normandy beaches on D-day, and on June 7/8 the Luftwaffe began redeploying aircraft to France for attacking the Normandy bridgehead.
Pointblank operations ended on the fifth day of the Invasion. and the highest priority of the Combined Bomber Offensive became operations against the German rocket weapons
Operation Crossbow
Crossbow was the code name of the World War II campaign of Anglo-American "operations against all phases of the German long-range weapons programme—operations against research and development of the weapons, their manufacture, transportation and their launching sites, and against missiles in flight"...
in June 1944 and the Oil Campaign
Oil Campaign of World War II
The Allied Oil Campaign of World War II was directed at facilities supplying Nazi Germany with petroleum, oil, and lubrication products...
in September. Tedder's proposal to keep oil targets as the highest priority and place "Germany's rail system in second priority" was appproved by the CSTC on November 1. On April 12, 1945, Strategic Bombing Directive No. 4 ended the strategic bombing campaign in Europe.
See also
- Operation Pointblank
- Operation CrossbowOperation CrossbowCrossbow was the code name of the World War II campaign of Anglo-American "operations against all phases of the German long-range weapons programme—operations against research and development of the weapons, their manufacture, transportation and their launching sites, and against missiles in flight"...
- Oil Campaign of World War IIOil Campaign of World War IIThe Allied Oil Campaign of World War II was directed at facilities supplying Nazi Germany with petroleum, oil, and lubrication products...
- Transportation Plan