Strategic bombing survey

The United States Strategic Bombing Survey was a board of experts assembled to produce an impartial assessment of the effects of Anglo-American strategic bombing of Nazi Germany during the European war. After publishing its report, the Survey turned its attention to the efforts against Imperial Japan, including a separate section on the recent atomic bombing.

In total, the reports contained 208 volumes for Europe and another 108 for the Pacific, comprising thousands of pages. The reports' conclusions were generally favourable about the contributions of Allied strategic bombing towards victory, calling it "decisive".

Although most of the Survey's members were military, about one-third of the 1,000-member group were civilian. The Board was not associated with any branch of the military, established directly by the US Secretary of War Henry L. Stimson and chaired by a civilian, Franklin D'Olier.

Europe
The Survey was formed on 3 November 1944 by Henry Stimson in response to a directive by President Roosevelt. The Survey was tasked with producing an impartial report on the effects of the bombing against Nazi Germany, in order to:


 * aid the upcoming campaign against the Japanese home islands,
 * to establish a basis for evaluating the importance and potentialities of air power as an instrument of military strategy,
 * for planning the future development of the United States armed forces, and
 * for determining future economic policies with respect to the national defense.

The Report, along with some 200 supporting documents, was released on 30 September 1945. The major conclusion of the report was that strategic bombing, particularly the destruction of the oil industry and truck manufacturing had greatly contributed to the success of the Allies in World War II. However, despite the overall contribution of the bombing, the survey concluded that the impact of strategic bombing could not be separated from the general collapse of Germany in 1945.

Successes
The Survey noted several successes against crucial industrial areas:


 * "The Attack on Oil": This section of the USSBS presents the statistics for the Oil Plan portion of the bombing campaign against petroleum, oil, and lubrication (POL) products, particularly regarding the Leuna complex that produced a notable portion of the synthetic oil. The survey repeats the Nazi Germany position that the campaign was "catastrophic".
 * Ammunition: Production fell markedly in 1944 and the arms industry shipped bombs and shells packed partly with rock salt, as Germany ran out of nitrate, a vital ingredient. Finally, Albert Speer, head of the Nazi economy, shifted the last nitrogen from the war effort to agriculture because he believed the war was lost and next year's crops were more important.
 * Truck manufacturing: Concentrated in three factories. Opel and Daimler Benz works were bombed. The Ford Motor Company plant at Cologne was not bombed, but went out of production because its suppliers had been bombed out.
 * Submarine manufacturing was halted.

Failures
The Survey also noted a number of failed or outcomes of limited success:


 * Aviation production: "In 1944 the German air force is reported to have accepted a total of 39,807 aircraft of all types -- compared with 8,295 in 1939, or 15,596 in 1942 before the plants suffered any attack." According to the report, almost none of the aircraft produced in 1944 were used in combat and some may have been imaginary.
 * Armor production "reached its wartime peak in December 1944, when 1,854 tanks and armored vehicles were produced. This industry continued to have relatively high production through February 1945."
 * Ball bearings: "There is no evidence that the attacks on the ball-bearing industry had any measurable effect on essential war production."
 * "Secondary Campaigns" (Operation Chastise & Operation Crossbow): "The bombing of the launching sites being prepared for the V weapons delayed the use of V-l appreciably. The attacks on the V-weapon experimental station at Peenemunde, however, were not effective; V-l was already in production near Kassel and V-2 had also been moved to an underground plant. The breaking of the Mohne and the Eder dam, though the cost was small, also had limited effect."
 * Steel: The bombing greatly reduced production, but the resulting shortage had no contribution to the defeat.
 * Consumer goods: "In the early years of the war—the soft war period for Germany—civilian consumption remained high. Germans continued to try for both guns and butter. The German people entered the period of the air war well stocked with clothing and other consumer goods. Although most consumer goods became increasingly difficult to obtain, Survey studies show that fairly adequate supplies of clothing were available for those who had been bombed out until the last stages of disorganization. Food, though strictly rationed, was in nutritionally adequate supply throughout the war. The Germans' diet had about the same calories as the British."

On German production
The Survey concluded that one reason German production rose in so many areas was in part that the German economy did not go on a complete war footing until late 1942 and 1943. Up until then, factories had been on a single shift in many industries and the German economy was generally inefficient and not operating at full capacity. They also noted that women's participation in the manufacturing field remained low, lower than during World War I. The sections of the Survey regarding the German production system remain one of the best resources on the topic.

Pacific
After the European report was completed, the Survey turned its attention to the Pacific campaign. The report opens with a discussion of the Japanese strategic plans, which were based on an initial victory against the US Navy which would upset any US plans in the Pacific for an estimated 18 months to 2 years. During this time they planned to "speedily extract bauxite, oil, rubber and metals from Malaya, Burma, the Philippines and the Dutch East Indies, and ship these materials to Japan for processing". They also noted the belief that high casualties would not be accepted by the US democracy, and that if the initial campaigns were successful, a negotiated peace was possible.

Against shipping
The Survey received sufficient information to detail every ship used by the Japanese during the war. They noted that the Imperial Japanese Navy began the war with 381 warships of approximately 1,271,000 tons, and completed another 816 ships of 1,048,000 tons during the war. Of these, 1,744,000 tons were sunk; "625,000 tons were sunk by Navy and Marine aircraft, 375,000 tons by submarines, 183,000 tons by surface vessels, 55,000 tons by Army aircraft, and 65,000 tons by various agents".

The Japanese merchant fleet was likewise destroyed. They started the war with 6,000,000 tons of merchant ships over 500 tons gross weight, which was alone not sufficient to provide for the wartime economy. Another 4,100,000 tons were constructed, captured or requisitioned. However, 8,900,000 tons were sunk, the vast majority of their fleet. Of this, "54.7 percent of this total was attributable to submarines, 16.3 percent to carrier based planes, 10.2 percent to Army land-based planes and 4.3 percent to Navy and Marine land-based planes, 9.3 percent to mines (largely dropped by B-29s), less than 1 percent to surface gunfire, and the balance of 4 percent to marine accidents."

Against the home islands
In total, Allied aircraft dropped 656,400 tons of bombs on Japanese targets, 160,800 tons on the home islands. This was much smaller than the 2,700,000 tons dropped over Europe, or even the 1,360,000 tons on Germany.

After initial attacks from high-altitude precision bombing in which less than 10% of the bombs fell near their targets, the Allied Air Forces switched to low-level night-time incendiary attacks against Japanese cities. On the night of 9-10 March 1945, 16 square miles of downtown Tokyo were burned flat and tens of thousands were killed by the USAAF B-29s. (The Survey estimated that 88,000 died, while the Tokyo Fire Department estimated 97,000. Historian Richard Rhodes estimated more than 100,000, though journalist Mark Selden considered even this figure to be too low.) In the following 10 days, a total of 31 square miles were destroyed. The Survey notes that these attacks had little direct effect on manufacturing, with factories that were hit by bombs having less drop off in production than those that did not. However, they also noted that production dropped by 54% during this period due to the effects of bombing: the killing, injuring and dehousing of the workers as well as the destruction of the transportation network. They noted a precipitous reduction in food availability as well, dropping from about 2,000 calories per day at the start of the war, to 1,680 for industrial workers at the height of the campaign, and less for non-essential workers.

Atomic bombing
The Survey dedicates a separate section of the reports to the atomic bombings of Hiroshima and Nagasaki.

They noted that although the blast wave was of about the same pressure as that of a high-explosive bomb, the duration of the effect was longer and that brick buildings were collapsed as far as 7,300 feet at Hiroshima and 8,500 feet at Nagasaki, while traditional wood houses were about the same, while reinforced-concrete structures suffered structural damage or collapse up to 700 feet at Hiroshima and 2,000 feet at Nagasaki.

In Hiroshima, approximately 60,000 to 70,000 people were killed, and 50,000 were injured. This is out of a pre-war population of about 340,000 that had been reduced to 245,000 through evacuations. Of approximately 90,000 buildings in the city, 65,000 were rendered unusable and almost all the remainder received at least light superficial damage.

In Nagasaki, approximately 40,000 persons were killed or missing and a like number injured. This was from a population of about 285,000, which had been reduced to around 230,000 by August 1945. Of the 52,000 residential buildings in Nagasaki 14,000 were totally destroyed and a further 5,400 badly damaged. The vast majority of Nagasaki's industrial output was from the Mitsubishi factories and steel plant, which was 58 and 78 percent destroyed, respectively.

Unlike Hiroshima, Nagasaki featured extensive civilian bomb shelters in the form of tunnels cut into the sides of hills. "...all the occupants back from the entrances survived, even in those tunnels almost directly under the explosion. Those not in a direct line with the entrance were uninjured. The tunnels had a capacity of roughly 100,000 persons. Had the proper alarm been sounded, and these tunnel shelters been filled to capacity, the loss of life in Nagasaki would have been substantially lower."

The report also concluded that: "Based on a detailed investigation of all the facts, and supported by the testimony of the surviving Japanese leaders involved, it is the Survey's opinion that certainly prior to 31 December 1945, and in all probability prior to 1 November 1945, Japan would have surrendered even if the atomic bombs had not been dropped, even if Russia had not entered the war, and even if no invasion had been planned or contemplated."