Timeline #2 - The 509th; The
SEVEN B-29's of the Hiroshima Mission:
- The "Enola Gay", piloted by Col. Tibbets
carries the "Little Boy" uranium bomb.
- "The Great Artiste", piloted by Maj.
Charles Sweeney, is assigned to drop the three instruments used to
measure the blast effects of the bomb.
- "#91" (unnamed at the time - later
"Necessary Evil"), flown by Capt. George Marquardt,
carries the scientific observers.
- "Top Secret", flown by Capt. Chuck
Knight, acts as a standby aircraft and flew to Iwo Jima in the event
of mechanical problems with the Enola Gay.
- "Straight Flush" will act as a weather
plane and fly ahead to primary target of Hiroshima.
- "Jabbitt III" will act as a weather plane
and fly ahead to the secondary target of Kokura.
- "Full House" will act as a weather plane
and fly ahead to the alternate target of Nagasaki.
The Mission's Timeline...
8/4/45; 2:00 PM - General Curtis LeMay officially
confirms that the mission will take place on August 6. After
seeing numerous B-29 crashes during take-off, Navy Capt. Parsons, head
of the Los Alamos Scientific Team, suggests arming the bomb in flight,
inserting the explosive charge during the early
stage of the mission while flying at low level.
8/4/45; 3:00 PM - Shortly after evening mess, the
seven crews that would participate in the mission were gathered for a
pre-flight briefing, which included discussions on routes, altitudes,
radio frequencies and weather reports. Radio call was changed from
VICTOR to DIMPLES. The first leg would be flown at 5,000 feet in
order for Parsons to arm the bomb in flight.
8/5/45; 12:00 Noon - Little Boy, which is a uranium
type bomb, is 12 feet long, is 28 inches in diameter, weighs 9,000
pounds, and was painted a dull gun metal gray is taken by trailer from
the ordnance hut and placed in the loading pit.
8/5/45; 3:00 PM - Little Boy is loaded into the Enola
Gay. Parsons soon arrives and began practicing arming the bomb
using the Double Plug system. He emerged two hours later confidant
he could arm the bomb in flight.
8/5/45; 11:00 PM; The briefing for the three crews
that would actually fly the 13 hour trip to the target began.
Although the film of the Alamagordo (Trinity) test was not available,
Parsons, who had seen the test, told the group about the bomb. The
word "atom" or "atomic" was never mentioned.
The Enola Gay would drop the bomb and immediately bank 155 degrees to
the right. Sweeney, in The Great Artiste, would drop the 3
instruments at the same moment and immediately bank 155 degrees to the
left. Marquardt, in the photo and observation plane, would fly
slightly behind the others and thus would be out of immediate danger.
8/6/45; 12:00 Mid-Night - The final pre-flight
briefing was held.
8/6/45; 1:37 AM - The 3 weather planes, Straight
Flush, Full House and Jabbitt III, take off from Tinian.
8/6/45; 2:45 AM - The Enola Gay, 15,000 pounds
over-weight at 65 tons, with a crew of 12, 7,000 gallons of fuel, and
the 9,000 pound bomb lifts off from Tinian.
8/6/45; 2:47 AM - The Great Artiste takes off.
8/6/45; 2:49 AM - #91 takes off.
8/6/45; 2:51 AM - Top Secret takes off.
8/6/45; 2:53 AM - Navy Capt. Parsons and Morris
Jeppson descend into the bomb bay of the Enola Gay and begin the arming
procedure; with Jeppson holding a flashlight and Parsons
inserting the components.
8/6/45; 2:55 AM - The Enola Gay crossed the northern
tip of Saipan. Communications between Parsons and Tibbets was made
possible with an intercom. Parsons began by confirming that the
"green" plugs blocking the firing signal and preventing
accidental detonation were in place. Parsons then removed a rear
plate, and an armor plate beneath, exposing the cannon breech and
unscrewed the breech plug. He then inserted the four pieces of
cordite into the breech, then replaced the breech plug. He then
connected the firing line and reinstalled the two metal plates.
Little Boy was not armed until the cordite charges had been
loaded. Coded messages were then sent back to General Farrell,
indicating Parsons' progress.
8/6/45; 3:18 AM - Parsons completes the procedure; Parsons and Jeppson would continue
to monitor the bomb electronically throughout the mission. The 3
planes remained in radio contact.
8/6/45; 5:34 AM - Tibbets ascended from 4,600 feet to
5,500 feet. 20 minutes later, they reached an initial cruising
altitude of 9,300 feet.
8/6/45; 5:52 AM - Enola Gay arrives over Iwo Jima and
rendezvous with other planes. Top Secret, the back up, has landed
on Iwo Jima.
8/6/45; 6:07 AM - The Enola Gay, The Great Artiste,
and #91, now head for Japan, a little more than 3 hours away. They
are still unsure of their target.
8/6/45; 7:30 AM - Jeppson enters the bomb bay on
the Enola Gay and exchanges the "green" plugs with
"red" ones, thus activating the bombs internal
batteries. He then declares to Parsons that the bomb is ready.
8/6/45; 7:45 AM - The 3 planes slowly climbed to an
altitude of 30,700 feet.
8/6/45; 8:30 AM - Straight Flush, the weather plane,
radioed that Hiroshima had little cloud coverage (< 3/10 at all
altitudes). Sweeney and Marquardt also received this message and
there was no reason to break radio silence.
8/6/45; 8:32 AM - The Enola Gay and its two companions
turn toward Hiroshima.
8/6/45; 9:12:17 AM - Tibbets instructs crew members to
ready their goggles. The 3 minute bombing run began.
8/6/45; 9:13:47 AM - Tibbets turned control of the
Enola Gay over to the bombardier, Thomas Ferebee for the remainder of
8/6/45; 9:14:17 AM - Ferebee flicked the switch that
activated a high pitched tone which would ring for one minute before the
bomb was released. This tone was heard on each of the three
planes, as well as the 3 weather planes already more than 200 miles
8/6/45; 9:15:17 AM - The bomb was released from the
Enola Gay and the 3 instruments were dropped by parachute by The Great
Artiste. After releasing the bomb, both the Enola Gay and The
Great Artiste each turned into a 155 degree turn, losing 1,700 feet in
altitude at the process. All crew members put on their dark
glasses and prepared for the blast.
8/6/45; 9:16:00 - Little Boy exploded at an altitude
of 1,890 feet above the target. Yield was equivalent to 12,500
tons of TNT. The first shock wave
took about 1 minute to reach the planes which were now 9 miles
away. Crew member Caron could see the first shock wave coming
toward the plane at 1,100 ft./sec. Soon after, a second shock wave
(echo effect) hit the planes with less intensity. The instruments
which were dropped radioed blast information back to The Great
Artiste. A coded message was sent to General Farrell on Tinian
advising him of the successful detonation. The atomic mushroom
cloud remained visible for 90 minutes until the planes were more than
400 miles away.
8/6/45; 2:58 PM - The Enola Gay touches down on the
runway at Tinian Island, followed a short time later by The Great
Artiste and #91. Silver stars were awarded to each man involved
with the mission. Tibbets received the Distinguished Service
Cross. Mission debriefings were immediately conducted by Hazen
Payett, an intelligence officer.
8/7/45 - President Truman announces the bomb dropped
on Hiroshima. Radio Saipan began broadcasting surrender appeals
while aircraft fitted with giant loudspeakers flew over Japan carrying
the message of atomic destruction. The War Office printed several
million leaflets and a newspaper containing Sgt. Carron's photo of the
atomic cloud rising over Hiroshima.