Since everything was ready, Farrell telexed Groves to report that the mission could be flown on August 1; he would assume that the Spaatz directive of July 25 authorized such initiative unless Groves replied to the contrary.2553 The commanding general of the Manhattan Project let his deputy’s interpretation stand. Little Boy would have flown on August 1 if a typhoon had not approached Japan that day to intervene.
So the mission waited on the weather. On August 2, Thursday, the three B-29’s that carried Fat Man preassemblies arrived from New Mexico.2554 The assembly team of Los Alamos scientists and military ordnance technicians went to work immediately to prepare one Fat Man for a drop test and a second with higher-quality HE castings for combat.2555 The third preassembly would be held in reserve for the plutonium core scheduled to be shipped from Los Alamos in mid-August. “By August 3,” recalls Paul Tibbets, “we were watching the weather and comparing it to the [long-range] forecast. The actual and forecast weather were almost identical, so we got busy.”2556
Among other necessities, getting busy involved briefing the crews of the seven 509th B-29’s that would fly the first mission for weather reporting, observation and bombing. Tibbets scheduled the briefing for 1500 hours on August 4. The crews arrived between 1400 and 1500 to find the briefing hut completely surrounded by MP’s armed with carbines. Tibbets walked in promptly at 1500; he had just returned from checking out the aircraft he intended to use to deliver Little Boy, usually piloted by Robert Lewis: B-29 number 82, as yet unnamed. Deke Parsons joined him on the briefing platform. A radio operator, Sergeant Abe Spitzer, kept an illegal diary of his experiences at Tinian that describes the briefing.2557
The moment had arrived, Tibbets told the assembled crews. The weapon they were about to deliver had recently been tested successfully in the United States; now they were going to drop it on the enemy.
Two intelligence officers undraped the blackboards behind the 509th commander to reveal aerial photographs of the targets: Hiroshima, Kokura, Nagasaki. (Niigata was excluded, apparently because of weather.) Tibbets named them and assigned three crews—“finger crews”—to fly ahead the day of the drop to assess their cloud cover. Two more aircraft would accompany him to photograph and observe; the seventh would wait beside a loading pit on Iwo Jima as a spare in case Tibbets’ plane malfunctioned.
The 509th commander introduced Parsons, who wasted no words. He told the crews the bomb they were going to drop was something new in the history of warfare, the most destructive weapon ever made: it would probably almost totally destroy an area three miles across.
They were stunned. “It is like some weird dream,” Spitzer mused, “conceived by one with too vivid an imagination.”
Parsons prepared to show a motion picture of the Trinity test. The projector refused to start. Then it started abruptly and began chewing up leader. Parsons told the projectionist to shut the machine off and improvised. He described the shot in the Jornada del Muerto: how far away the light had been seen, how far away the explosion had been heard, the effects of the blast wave, the formation of the mushroom cloud. He did not identify the source of the weapon’s energy, but with details—a man knocked down at 10,000 yards, men 10 and 20 miles away temporarily blinded—he won their rapt attention.
Tibbets took over again. They were now the hottest crews in the Air Force, he warned them. He forbade them to write letters home or to discuss the mission even among themselves. He briefed them on the flight. It would probably go, he said, early on the morning of August 6. An air-sea rescue officer described rescue operations. Tibbets closed with a challenge, a final word Spitzer paraphrases in his diary:
The colonel began by saying that whatever any of us, including himself, had done before was small potatoes compared to what we were going to do now. Then he said the usual things, but he said them well, as if he meant them, about how proud he was to have been associated with us, about how high our morale had been, and how difficult it was not knowing what we were doing, thinking maybe we were wasting our time and that the “gimmick” was just somebody’s wild dream. He was personally honored and he was sure all of us were, to have been chosen to take part in this raid, which, he said—and all the other big-wigs nodded when he said it—would shorten the war by at least six months. And you got the feeling that he really thought this bomb would end the war, period.
The following morning, Sunday, Guam reported that weather over the target cities should improve the next day. “At 1400 on August 5,” Norman Ramsey records, “General LeMay officially confirmed that the mission would take place on August 6.”2558
That afternoon the loading crew winched Little Boy onto its sturdy transport dolly, draped it with a tarpaulin to protect it from prying eyes—there were still Japanese soldiers hiding out on the island, hunted at night by security forces like raccoons—and wheeled it to one of the 13 by 16-foot loading pits Kirkpatrick had prepared. A battery of photographers followed along to record the proceedings. The dolly was wheeled over the nine-foot pit on tracks; the hydraulic lift came up to relieve it of its bomb and detachable cradle; the crew wheeled the dolly away, removed the tracks, rotated the bomb 90 degrees and lowered it into the pit.2559
The world’s first combat atomic bomb looked like “an elongated trash can with fins,” one of Tibbets’ crew members thought.2560 With its tapered tail assembly that culminated in a boxed frame of stabilizing baffle plates it was 10½ feet long and 29 inches in diameter. It weighed 9,700 pounds, an armored cylinder jacketed in blackened dull steel with a flat, rounded nose. A triple fusing system armed it. The main fusing component was a radar unit adapted from a tail-warning mechanism developed to alert combat pilots when enemy aircraft approached from behind. “This radar device,” notes the Los Alamos technical history, “would close a relay [i.e., a switch] at a predetermined altitude above the target.”2561 For reliability Little Boy and Fat Man each carried four such radar units, called Archies. Rather than an approaching enemy aircraft, the bomb Archies would bounce their signals off the approaching enemy ground. An agreed reading by any two of the units would send a firing signal into the next stage of the fusing system, the technical history explains:
This stage consisted of a bank of clock-operated switches, started by arming wires which were pulled out of the clocks when the bomb dropped from the plane’s bomb bay. These clock switches were not closed until 15 seconds after the bomb was released. Their purpose was to prevent detonation in case the A[rchie] units were fired by signals reflected from the plane. A second arming device was a [barometric] pressure switch, which did not close until subject to a pressure corresponding to 7000 feet altitude.
Once it passed through the clock and barometric arming devices the Little Boy firing signal went directly to the primers that lit the cordite charges to fire the gun. Externally the fusing system revealed itself in trailing whips of radar antennae, clock wires threaded into holes in the weapon’s upper waist and holes in its tapered tail assembly that admitted external air to guarantee accurate barometry.
Loading the bomb was delicate: the fit was tight. A ground crew towed the B-29 to a position beside the loading pit, running onto a turntable the main landing gear on the wing nearer the pit. Towing the aircraft around on the turntable through 180 degrees positioned it over the pit. The hydraulic lift raised Little Boy to a point directly below the open bomb doors. A plumb bob hung from the single bomb shackle for a point of reference and jacks built into the bomb cradle allowed the crew to line up the bomb eye.
“The operation can be accomplished in 20 to 25 minutes,” a Boeing engineer commented in an August report, “but is a rather ticklish procedure, as there is very little clearance with the catwalks and, once installed, nothing holds the bomb but the single shackle and adjustable sway braces bearing on it.”2562
Though he flew it as his own, Robert Lewis had never named B-29 number 82. The day of the loading Tibbets consulted the officers in Lewis’ crew—but not Lewis—and did so. The 509th commander chose not pinu
ps or puns but his mother’s given names, Enola Gay, because she had assured him he would not be killed flying when he fought out with his father his decision to become a pilot. “Through the years,” Tibbets told an interviewer once, “whenever I got in a tight spot in a plane I always remembered her calm assurance. It helped. In getting ready for the big one I rarely thought of what might happen, but when I did, those words of Mom’s put an end to it.” He “wrote a note on a slip of paper,” located a sign painter among the service personnel—the man had to be dragged away from a softball game—and told him to “paint that on the strike ship, nice and big.”2563, 2564 Foot-high, squared brushstrokes went on at a 30-degree angle beneath the pilot’s window of the bullet-nosed plane, the middle name flushright below the first.
Lewis, a sturdy, combative two-hundred-pounder, had known for a day or two that Tibbets would pilot the mission, a disappointment, but still considered the special B-29 his own. When he dropped by late in the afternoon to inspect it and found ENOLA GAY painted on its fuselage he was furious. “What the hell is that doing on my plane?” one of his crew mates remembers him yelling.2565 He found out that Tibbets had authorized the christening and marched off to confront him. The 509th commander told him coolly, rank having its privileges, that he didn’t think the junior officer would mind. Lewis minded, but he could do no more than stow away his resentment for the war stories he would tell.
“By dinnertime on the fifth,” Tibbets narrates, “all [preparations were] completed.2566 The atom bomb was ready, the planes were gassed and checked. Takeoff was set for [2:45] a.m. I tried to nap, but visitors kept me up. [Captain Theodore J.] Dutch [Van Kirk, the Enola Gay’s navigator,] swallowed two sleeping tablets, then sat up wide awake all night playing poker.” The weapon waiting in the bomb bay took its toll on nerves.
“Final briefing was at 0000 of August 6,” Ramsey notes—midnight.2567 Tibbets emphasized the power of the bomb, reminded the men to wear the polarized goggles they had been issued, cautioned them to obey orders and follow their protocols. A weather officer predicted moderate winds with clouds over the targets clearing at dawn. Tibbets called forward a Protestant chaplain who delivered a prayer composed for the occasion on the back of an envelope; it asked the Almighty Father “to be with those who brave the heights of Thy heaven and who carry the battle to our enemies.”2568
After the midnight briefing the crews ate an early breakfast of ham and eggs and Tibbets’ favorite pineapple fritters. Trucks delivered them to their hardstands. At the Enola Gay’s hardstand, writes Ramsey, “amid brilliant floodlights, pictures were taken and retaken by still and motion picture photographers (as though for a Hollywood premiere).”2569 A photograph shows ten of the twelve members of the strike plane’s crew posed in flight coveralls under the forward fuselage by the nose wheel: boyish Van Kirk in overseas cap with his coveralls unzipped down his chest to expose a white T-shirt; Major Thomas Ferebee, the bombardier, a handsome Errol Flynn copy with an Errol Flynn mustache, resting a friendly hand on Van Kirk’s shoulder; Tibbets standing at the center of it all easily smiling, belted and trim, his hands in his pockets; at Tibbets’ left Robert Lewis, the only crew member wearing a weapon; small, wiry Lieutenant Jacob Beser beside Lewis awkwardly smiling, a Jewish technician from Baltimore added for the flight, responsible for electronic countermeasures to screen the Archie units from Japanese radar. In front of the officers kneel the slimmer, mostly younger enlisted men (though the entire flight crew was young, Tibbets now all of thirty years old): radar operator Sergeant Joseph Stiborik; tail gunner Staff Sergeant Robert Caron, Brooklyn-born, wearing a Dodgers baseball cap; radio operator Private Richard R. Nelson; assistant engineer Sergeant Robert H. Shumard; flight engineer Staff Sergeant Wyatt Duzenbury, thirty-two, a former Michigan tree surgeon who thought the bomb looked like a tree trunk. An eleventh member of the crew, 2nd Lieutenant Morris Jeppson, an ordnance expert, would assist Deke Parsons in arming and monitoring Little Boy. Parsons, the twelfth man, resisted photographing but was flying the mission as weaponeer.
The three weather planes and the Iwo Jima standby had already left. Tibbets ordered Wyatt Duzenbury to start engines at 0227 hours. Pilot and copilot sat side by side just back of the point where the cylindrical fuselage began to curve inward to form the bullet-shaped nose; Ferebee, the bombardier, sat a step down ahead of them within the nose itself, an exposed position but a good view. Almost everything inside the aircraft was painted a dull lime green. “It was just another mission,” Tibbets says, “if you didn’t let imagination run away with your wits.”2570 As Dimples Eight Two, the Enola Gay’s unlikely designation that day, he reconstructs his dialogue with the Tinian control tower:
I forgot the atom bomb and concentrated on the cockpit check.
I called the tower. “Dimples Eight Two to North Tinian Tower. Taxi-out and take-off instructions.”
“Dimples Eight Two from North Tinian Tower. Take off to the east on Runway A for Able.”
At the end of the runway, another call to the tower and a quick response: “Dimples Eight Two cleared for take-off.”
Bob Lewis called off the time. Fifteen seconds to go. Ten seconds. Five seconds. Get ready.
At that moment the Enola Gay weighed 65 tons. It carried 7,000 gallons of fuel and a four-ton bomb. It was 15,000 pounds overweight. Confident the aircraft was maintained too well to falter, Tibbets decided to use as much of the two-mile runway as he needed to build RPM’s and manifold pressure before roll-up.
He eased the brakes at 0245, the four fuel-injected Wright Cyclone engines pounding. “The B-29 has lots of torque in take-off,” he notes. “It wants to swerve off the runway to the left. The average mass-production pilot offsets torque by braking his right wheels. It’s a rough ride, you lose ten miles an hour and you delay the take-off.” Nothing so crude for Tibbets. “Pilots of the 509th Group were taught to cancel torque by leading in with the left engines, advancing throttles ahead of the right engines. At eighty miles an hour, you get full rudder control, advance the right-hand engines to full power and, in a moment, you’re airborne.”2571 Takeoff needed longer than a moment for the Enola Gay’s overloaded flight. As the runway disappeared beneath the big bomber Lewis fought the urge to pull back the yoke. At the last possible takeoff point he thought he did. Not he but Tibbets did and abruptly they were flying, an old dream of men, climbing above a black sea.
Ten minutes later they crossed the northern tip of Saipan on a course northwest by north at 4,700 feet.2572 The air temperature was a balmy 72°. They were flying low not to burn fuel lifting fuel and for the comfort of the two weaponeers, Parsons and Jeppson, who had to enter the unpressurized, unheated bomb bay to finish assembling the bomb.
That work began at 0300. It was demanding in the cramped confines of the loaded bomb bay but not dangerous; there was only minimal risk of explosion. The green plugs that blocked the firing signal and prevented accidental detonation were plugged into the weapon; Parsons confirmed that fact first of all. Next he removed a rear plate; removed an armor plate beneath, exposing the cannon breech; inserted a wrench into the breech plug and rotated the wrench about sixteen times to unscrew the plug; removed it and placed it carefully on a rubber pad. He inserted the four sections of cordite one at a time, red ends to breech.2573 He replaced the breech plug and tightened it home, connected the firing line, reinstalled the two metal plates and with Jeppson’s help removed and secured the tools and the catwalk. Little Boy was complete but not yet armed. The charge loading took fifteen minutes. They spent another fifteen minutes checking monitoring circuitry at the panel installed at the weaponeer’s position in the forward section. Then, except for monitoring, their work was done until time to arm the bomb.
Robert Lewis kept a journal of the flight. William L. Lawrence, the New York Times science editor attached to the Manhattan Project, had traveled out to Tinian expecting to go along. When he learned to his bitter disappointment that his participation had been deleted he asked Lewis to take notes. The
copilot imagined himself writing a letter to his mother and father but appears to have sensed that the world would be looking over his shoulder and styled his entries with regulation Air Force bonhomie. “At forty-five minutes out of our base,” he began self-consciously, “everyone is at work.2574 Colonel Tibbets has been hard at work with the usual tasks that belong to the pilot of a B-29. Captain Van Kirk, navigator, and Sergeant Stiborik, radio operator, are in continuous conversation, as they are shooting bearings on the northern Marianas and making radar wind runs.” No mention of Parsons or Jeppson, oddly enough, though Lewis could have seen the bomb hanging in its bay through the round port below the tunnel opening straight back from his copilot’s seat.
The automatic pilot, personified as George, was flying the plane, which Tibbets stationed below 5,000 feet. The commander realized he was tired, Lewis records: “The colonel, better known as ‘the Old Bull,’ shows signs of a tough day.2575 With all he’s had to do to get this mission off, he is deserving of a few winks, so I’ll have a bite to eat and look after ‘George.’ ”
Rather than sleep Tibbets crawled through the thirty-foot tunnel to chat with the waist crew, wondering if they knew what they were carrying. “A chemist’s nightmare,” the tail gunner, Robert Caron, guessed, then “a physicist’s nightmare.”2576 “Not exactly,” Tibbets hedged. Tibbets was leaving by the time Caron put two and two together:
[Tibbets] stayed . . . a little longer, and then started to crawl forward up the tunnel. I remembered something else, and just as the last of the Old Man was disappearing, I sort of tugged at his foot, which was still showing. He came sliding back in a hurry, thinking maybe something was wrong. “What’s the matter?”