The Target Committee (Kindle Single) (3 page)

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And so, with Groves’ express wishes uppermost in mind, the May 10 committee meeting began. Oppenheimer ran through the agenda:

A. Height of Detonation

B. Report on Weather and Operations

C. Gadget Jettisoning and Landing

D. Status of Targets

E. Psychological Factors in Target Selection

F. Use Against Military Objectives

G. Radiological Effects

H. Coordinated Air Operations

I. Rehearsals

J. Operating Requirements for Safety of Airplanes

K. Coordination with 21st Program.
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Whether or to what extent the targeted cities had military installations was not discussed at this point, according to the minutes.
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Dr. Stearns named the targets on an updated short list in order of preference: Kyoto, Hiroshima and Yokohama, plus two new cities, Kokura, on the island of Kyushu, and Niigata, the capital city of Niigata Prefecture, on the north-west coast of Honshu.

The target list was always being reshuffled or amended, according to new priorities. Nagasaki had not yet made the cut. These five cities were all “large urban areas of more than three miles in diameter”; “capable of being effectively damaged by the blast”; and “likely to be unattacked by next August.”
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Of these, Kyoto and Hiroshima were classified as “AA” targets, because they best matched Groves’ criteria put forward prior to the meeting.

Kyoto, a large industrial city with a population of one million, met most of the committee’s criteria. Thousands of Japanese workers and hundreds of businesses had moved there to escape destruction elsewhere. Furthermore, Kyoto was a cultural and intellectual center, meaning the residents were “more likely to appreciate the significance of such a weapon as the gadget.” Groves ranked Kyoto his preferred no. 1 target, and von Neumann backed the choice of Kyoto as the target for the first atomic bomb.

Hiroshima, a city of 318,000, held similar appeal. It was “an important army depot and port of embarkation,” the meeting heard, situated in the middle of an urban area “of such a size that a large part of the city could be extensively damaged.” The hills that surrounded the city were “likely to produce a focusing effect which would considerably increase the blast damage.” On top of this, Hiroshima’s location within the Ota River delta meant that it was
not a good target for firebombs, and would likely remain intact until the atomic bomb was ready.

The committeemen then heard the case for the remaining targets.

Yokohama was classified as an “A” target. It was an important urban industrial area and had so far been untouched. Industrial activities there included aircraft manufacture, machine tools, docks, electrical equipment and oil refineries. The committee was informed that:

As the damage to Tokyo has increased, additional industries have moved to Yokohama. It has the disadvantage of the most important target areas being separated by a large body of water and of being in the heaviest anti-aircraft concentration in Japan. For us it has the advantage as an [alternative] target for use in case of bad weather [and] of being rather far removed from the other targets considered.

Kokura was an ancient castle town that guarded the Straits of Shimonoseki. It hosted one of Japan’s biggest arsenals, surrounded by urban industrial structures, including coal and ore docks, steelworks, extensive railway yards and an electric power plant. Replete with military vehicles, ordnance, heavy naval guns and, reportedly, poison gas, this arsenal made Kokura the most obvious military target. Its dimensions were such that if a bomb were properly placed, “full advantage could be taken of the higher pressures immediately underneath the bomb for destroying the more solid structures,” while at the same time “considerable blast damage could be done to more feeble structures further away.” Like Yokohama, Kokura was classified as an A target.

Niigata was a port of embarkation on the north-west coast of Honshu. The committee members were told that:

[The city’s] importance is increasing as other ports are damaged. Machine tool industries are located there and it is a potential center for industrial dispersion. It has oil refineries and storage.

Niigata was classified as a “B” target. Its industrial plants were built of fire-resistant materials, and its houses constructed from heavy plaster, to protect against harsh winters. Hence, it was less combustible.

The possibility of bombing the Japanese emperor’s palace was also raised – a spectacular idea, they concurred, but militarily impractical. “It was agreed that we should not recommend it . . . [but] should obtain information [that might] determine the effectiveness of our weapon against this target,” the meeting decided. In any case, Tokyo, already firebombed several times, had been struck from an earlier list because an atomic bomb would merely “make the rubble dance,” to paraphrase Churchill.

The meeting barely touched upon whether the cities – with the exception of Kokura – had any appeal as military targets, or what their military functions were. There wasn’t much to discuss: Hiroshima’s port and its main industrial and military districts were located outside the urban regions, to the south-east of the city – well away from the target zone of the city center. A few thousand conscripts unfit for battle were garrisoned in the military barracks in the center of town, but it was otherwise populated by civilians.
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Japan’s ancient capital of Kyoto had no significant military installations either. However, its beautiful wooden shrines and temples recommended it, as Groves had said earlier, as both a “sentimental” and highly combustible target.

The committee moved on to the risks. Oppenheimer briefly assessed the radiation risk: US aircraft should not fly within two and a half miles of the detonation point, he advised, to “avoid the cloud of radioactive materials.” The risks would be discussed in greater detail at the next meeting, on the following day. The radiation risk to Japanese civilians was not
discussed at any of the meetings of the Target Committee.

The committeemen next raised the question of whether incendiary bombers should attack the city after the nuclear strike. “This has the great advantage,” said one committee member, “that the enemies’ fire-fighting ability will probably be paralyzed by the gadget so that a very serious conflagration [will start].” The ensuing firestorm, however, might confuse photo-reconnaissance of the atomic damage and subject aircrews to radioactive contamination. For this reason, they rejected the proposal that firebombing raids should follow the atomic bomb.

Summing up, the committeemen unanimously agreed that the bomb should be dropped, without warning, on a large city center, the psychological impact of which should be so spectacular as to ensure “international recognition” of the new weapon. Groves received a full report of the proceedings on May 12.
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The Target Committee met the next day, May 11, to discuss the technical aspects of the mission. Before the meeting, Oppenheimer sent Farrell a longer description of the likely effects of radiation. The uranium bomb, he warned, as distinct from the plutonium bomb, being concurrently developed, would release toxic material equivalent to a billion single lethal doses; and radiation emissions would be lethal within a 1-mile radius.

Within a second of the blast, gamma radiation capable of penetrating concrete and packed soil equivalent to about 10
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curies would coat a large section of the targeted city, falling, within a day, to “about 10 million curies.” (One curie is the level of radiation emitted by a single gram of radium.) “If the bomb is delivered during rain,” Oppenheimer added, “most of the active material will be brought down . . . in the vicinity of the target area.” Otherwise, the radioactive material would spread over a wide area – unless the targeted city was surrounded by hills, like Hiroshima, which would contain the spread of the radioactive material, maximizing the damage and casualty rate.

Exposure to gamma rays causes diffuse damage throughout the human body, including radiation sickness, cell death due to damaged DNA, and increased incidence of cancer. The full effects were not fully understood at the time, but the scientists certainly knew the lethal properties of radiation, for which there was ample evidence (including the “Radium Girls,” young workers in a watch factory in New Jersey who, in 1917, had ingested lethal amounts of radium from fluorescent paint, by licking their brushes to give them a fine point; dead fish in the rivers near Manhattan Project sites; and the Curies’ findings, to name a few).

Oppenheimer therefore warned that the delivery aircraft and follow-up planes should maintain a minimum distance of 2.5 miles from the detonation point to avoid radioactive contamination. Monitoring of ground radiation in the vicinity would be necessary for some weeks, he said, after which the area should be “quite safe to enter.”
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The Target Committee regrouped at the Pentagon on May 28 (Oppenheimer sent a representative). Two individuals critical to the success of the atomic mission addressed the committee. They were a pilot, Colonel Paul Tibbets, and a flight commander, Frederick Lincoln Ashworth. Both had had a long involvement in the nuclear mission and were fully apprised of every secret associated with the Manhattan Project. And both were, crucially, extremely good at their jobs.

Tibbets

Tibbets had been selected to fly the plane that would deliver the first atomic bomb. The
youngest man in the room, Tibbets carried himself with a maturity beyond his 30 years. He seemed unperturbed at being among the very few who knew the true purpose of the mission – or perhaps he simply did not feel as other men do? No plane had dropped an atomic bomb; none had flown out of a radioactive cloud. Yet he was calm and cool, as if this were an everyday task he had been given to do.

Tibbets’ technical skill and proven courage had drawn the attention of the top brass at the US Army’s Strategic Air Service. A veteran of dozens of combat missions over Europe and North Africa, he was among the most experienced B-29 test pilots and one of the finest bomber pilots in the US Air Force. He was exceptionally brave, too: Tibbets had flown the lead plane in the Americans’ first daylight heavy bomber mission over occupied Europe on August 17, 1942, and again in the first American raid of more than 100 bombers on October 9 that year.

General “Hap” Arnold had hand-picked Tibbets for the project in the summer of 1944. The young man was appointed to command the 509th Composite Group, a unit within the US Army Air Forces specially selected to carry out the top-secret mission. Tibbets’ candor had startled his examiners during his security clearance tests. Asked whether he had ever been arrested, Tibbets admitted he had, ten years earlier, for having sex in the back seat of a car on Florida Beach.
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Tibbets actually enjoyed life at Wendover Field, the loathed air base on the Utah–Nevada border, which Bob Hope, on a brief visit, called “Leftover Field.” The isolation, the rigid command structure, the thoroughly scheduled days, all appealed to this ascetic officer. Orders, methods and results – the stuff of carefully planned action – sustained him. He described his mission to his superiors with the brevity of one for whom words, unless in the service of his appointed task, were a waste of time. His mission was, he said, “to wage atomic war.”
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Tibbets had unlimited security clearance. The young colonel needed only to say the code word “silverplate” and he got what he wanted – for example, the power to raise several squadrons, known as Tibbets’ Private Air Force. The personnel chosen for 509th Composite Group were taken from the 393d Heavy Bombardment Squadron, chosen for its high reputation. Special agents scrutinized every man and reported the slightest security breach to Tibbets, who learned the details of each member’s drinking habits, sex life, family and political orientation. Those who failed were packed off to remote air bases – in North Alaska, for example, where they could talk to “any polar bear or walrus” willing to listen, Tibbets later wrote.
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Those who met Tibbets’ exacting standards formed the kernel of the 509th. Three men convicted of manslaughter and several former criminals who had falsified their names to enlist were among the successful candidates. Tibbets offered to return their conviction files – with matches to burn them – if the mission succeeded. He valued their air skills over their moral rectitude.

The group trained all day, every day. Tibbets would “drill, drill and further drill his crews, until the best of them could hit the ground within just twenty-five feet of the bull’s eye.”
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None of them knew the nature of their mission. Tibbets never spoke of it with his crew, and he was in any case forbidden to use the words “atomic” and “radioactive.”

Tibbets’ confidence and notoriety rose in tandem with the distant respect that attached to his name. He dared even to correct the fearsome Curtis LeMay. The atomic delivery aircraft must fly
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25,000 feet, he told the commander at a meeting in Guam. The “special weapon” would destroy a plane flying under that, he explained.
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Ashworth

Frederick Lincoln Ashworth, a native of Beverly, Massachusetts, had graduated from the US Naval Academy at Annapolis, Maryland, in 1933. Like many of his military colleagues on the Manhattan Project, he had performed with exceptional courage in combat operations prior to joining the atomic mission. As the commander of Torpedo Squadron Eleven (VT-11), a Grumman TBF Avenger unit based on Guadalcanal, he flew patrol, search, spotting, strike, and night mine-laying missions in the struggle for control of the Solomon Islands, for which he was awarded the Distinguished Flying Cross. He also participated in the Gilbert and Marshall Islands campaign, as aviation officer on the staff of Vice Admiral Richmond K. Turner’s V Amphibious Corps.
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