Tag Archives: Glenn L. Martin – Nebraska Company

Medal of Honor, Staff Sergeant Henry Eugene Erwin, United States Army Air Forces

Aviation, , , , , , , , , , , , , , , ,
Private First Class Henry Eugene Erwin, Air Corps, United States Army, circa 1943. (U.S. Air Force)

MEDAL OF HONOR

STAFF SERGEANT HENRY EUGENE ERWIN (Air Mission)

Rank and organization: Staff Sergeant, U.S. Army Air Corps, 52d Bombardment Squadron, 29th Bombardment Group, 20th Air Force.

Place and date: Koriyama, Japan, 12 April 1945.

Entered service at: Bessemer, Ala.

Born: 8 May 1921, Adamsville, Ala.

G.O. No.: 44, 6 June 1945.

Citation: He was the radio operator of a B-29 airplane leading a group formation to attack Koriyama, Japan. He was charged with the additional duty of dropping phosphoresce smoke bombs to aid in assembling the group when the launching point was reached. Upon entering the assembly area, aircraft fire and enemy fighter opposition was encountered. Among the phosphoresce bombs launched by S/Sergeant. Erwin, 1 proved faulty, exploding in the launching chute, and shot back into the interior of the aircraft, striking him in the face. The burning phosphoresce obliterated his nose and completely blinded him. Smoke filled the plane, obscuring the vision of the pilot. S/Sergeant. Erwin realized that the aircraft and crew would be lost if the burning bomb remained in the plane. Without regard for his own safety, he picked it up and feeling his way, instinctively, crawled around the gun turret and headed for the copilot’s window. He found the navigator’s table obstructing his passage. Grasping the burning bomb between his forearm and body, he unleashed the spring lock and raised the table. Struggling through the narrow passage he stumbled forward into the smoke-filled pilot’s compartment. Groping with his burning hands, he located the window and threw the bomb out. Completely aflame, he fell back upon the floor. The smoke cleared, the pilot, at 300 feet, pulled the plane out of its dive. S/Sergeant. Erwin’s gallantry and heroism above and beyond the call of duty saved the lives of his comrades.

“Red Erwin stands with a painting depicting his act of heroism in the B-29 bomber, City of Los Angeles, on that fateful day.” (U.S. Air Force 170331-F-ZZ999-103))
Crew of the B-29 Superfortress “City of Los Angeles:” Front row, left to right: Vern W. Schiller, flight engineer; Henry E. Erwin, radio operator; Howard Stubstad, CFC gunner. Standing, Pershing Younkin, navigator; Roy Stables, pilot; William Loesch, bombardier; Leo D. Connors, radar bombardier; George A. Simeral, aircraft commander. (Alabama Department of Archives & History Q8799)

XXI Bomber Command’s Mission for 12 April 1945 was an attack against the Hodogaya Chemical Plant (Target ) at Koriyama, a city on the island of Honshu, Japan. The chemical plant produced tetraethyl lead, a critical ingredient in high-octane aviation gasoline. Eighty-five B-29 Superfortress long-range heavy bombers took of from their base at North Field on the island of Guam, the largest and southernmost of the Marianas. Each bomber was loaded with 500-pound (227 kilogram) AN-M64 general purpose demolition bombs. The planned time over the target was 12:35–13:26, with the bombers attacking at altitudes of 7,000 to 9,000 feet (2,134–2,743 meters). The weather report for the target area was clear, with visibility of 15 miles (24 kilometers).

29th Bombardment Group (Very Heavy) B-29 Superfortresses at North Field, Guam, 1945. (U.S. Air Force)

Koriyama was 1,506 miles (2,424 kilometers) from North Field. With a round-trip distance of 3,041 miles (4,894 kilometers), this was the longest bombing mission flown up to that time.

Navigation Track Chart, XXI Bomber Command Missions No. 64 and 65. (U.S. Air Force)

City of Los Angeles, a Martin-Omaha B-29-25-MO Superfortress, 42-65302, was the  lead ship of the 52nd Bombardment Squadron, 29th Bombardment Group. The Superfortress was under the command of Captain George Anthony Simeral. The 52nd squadron’s commander, Lieutenant Colonel Eugene O. Strouse, was on board as co-pilot.

B-29 Superfortress very long range heavy bombers of the 29th Bombardment Group (Very Heavy), 314th Bombardment Wing (Very Heavy), XXI Bomber Command. (U.S. Air Force)
Aogashima (Landsat)

The 52nd Squadron’s assembly point was over over Aogashima, a small volcanic island of the Izu archipelago in the Philippine Sea, 222 miles (357 kilometers) south of Tokyo.

It was near this island that City of Los Angeles‘s radio operator, Red Erwin, dropped white phosphorus signal flares to give the squadron a visual reference point.

When the faulty signal flare prematurely ignited, it burned at about 1,300 °F. (704 °C.) and filled the cockpit with dense smoke. The other crew members could not see the difficulty Erwin was having trying to drop the flare overboard.

Erwin was gravely injured. Phosphorus self-ignites in the presence of air. With particles of phosphorus all over, his body was still on fire. The phosphorus could not be extinguished.

A B-29 Superfortress circles Mount Suribachi, a 554-foot (169 meter) volcano at the southwestern end of Iwo Jima, circa 1945.

Captain Simeral aborted the mission and turned City of Los Angeles toward the island of Iwo Jima in the Volcano Islands, where an emergency landing field for the B-29s had been built. Iwo was the closest point where Erwin could receive medical treatment.

Erwin’s injuries were so severe that he was not expected to survive. He was evacuated to Fleet Hospital 103 at Guam.

Fleet Hospital 103, Guam, 1945. (U.S. Navy)

Major General Curtis E. LeMay, commanding XXI Bomber Command, and Brigadier General Lauris Norstad, Chief of Staff, Twentieth Air Force, sent a recommendation for the Medal of Honor to Headquarters, U.S. Army Air Forces in Washington, D.C.

The nearest Medal of Honor was in a display case in Hawaii. Because Erwin was not expected to survive, that medal was obtained and flown to Guam so that it could be presented while he was still alive. In a ceremony held in Orthopedic Wards 3 and 4 of Fleet Hospital 103, Major General LeMay and Major General Willis H. Hale, Commanding General, Army Air Forces, Pacific Ocean Areas, and Deputy Commander, Twentieth Air Force, presented the Medal of Honor to Staff Sergeant Henry Eugene Erwin, United States Army Air Forces.

Flight crew of B-29 City of Los Angeles and Staff Sergeant Henry E Erwin at his Medal of Honor presentation, 19 April 1945. Major General Willis H. Hale, Commanding General, Army Air Forces, Pacific Ocean Areas, is at right. (U.S. Air Force 170331-F-ZZ999-102)

General LeMay told Sergeant Erwin that, “Your effort to save the lives of your fellow airmen is the most extraordinary kind of heroism I know.”

General of the Army Henry H. Arnold, commanding the U.S. Army Air Forces, wrote to him, “I regard your act as one of the bravest in the records of the war.”

Red Erwin was the only crew member of a B-29 Superfortress to be awarded the Medal of Honor during World War II.

Red Erwin underwent 41 surgical procedures. The phosphorus particles in his body continued smoldering for months. Erwin was hospitalized for 2½ years before he was discharged from the U.S. Army Air Forces as a master sergeant, 8 October 1947.

Major General Willis H. Hale bestows the Medal of Honor on Staff Sergeant Henry E. Erwin at Fleet Hospital 103, Guam, 19 April 1945. (U.S. Navy)
Staff Sergeant Henry E. Erwin. (U.S. Air Force 160613-D-LN615-0038)

Henry Eugene Erwin was born 8 May 1921, at Docena, a small mining village in Jefferson County, Alabama. He was the fourth of nine children of Walter Marshall Erwin, a weighman at a coal mine, and Pearl Landers Ervin.

Gene Erwin spent two years working with the Civilian Conservation Corps, a “New Deal” public work relief program. By 1940, he had found employment as a secretary with the Tennessee Coal, Iron and Railroad Company (TCI RR).

On 27 January 1942, Erwin enlisted in the Army Reserve Corps. He had red hair, brown eyes and a “ruddy” complexion, was 5 feet, 10 inches (1.75 meters) tall and weighed 165 pounds (75 kilograms). He was appointed an aviation cadet, Air Corps, 3 February 1943. Because of “flight deficiencies,” Cadet Erwin did not complete flight training and in June 1943 was reassigned for training as a radio operator and technician.

In April 1944, Erwin was assigned to the 52nd Bombardment Squadron (Very Heavy), at Dalhart Army Airfield, Texas, for B-29 Superfortress combat crew training.

Sergeant Henry E. Erwin married Miss Martha Elizabeth Starnes, 6 December 1944, at Ensley, Alabama. The ceremony was performed by Rev. Daniel E. Draper. They would have five children.

A B-29 Superfortress of the 29th Bombardment Group (Very Heavy), 314th Bombardment Wing, lands at North Field, Guam, in the Marianas. (U.S. Air Force)

The 52nd Squadron deployed to the Pacific in February 1945 as an element of the 29th Bombardment Group (Very Heavy), 314th Bombardment Wing (Very Heavy), XXI Bomber Command, Twentieth Air Force, based at North Field, Guam.

Mission Number 65 was Erwin’s eleventh combat mission.

Martha Erwin (standing) with Henry Erwin and his mother, Pearl Landers Erwin, circa 1945. (U.S. Air Force via Encyclopedia of Alabama)

Gene Erwin never fully recovered. Although he had been blinded by the phosphorus burns, he eventually regained his sight. His right arm was disabled, and his body was covered in scars.

When he was able to return to work, Erwin was employed the Veterans Administration, and remained there for thirty-seven years before retiring.

Master Sergeant Henry Eugene Erwin, United States Army Air Forces (Retired), died 16 January 2002 at Leeds, Alabama. His body was buried at the Elmwood Cemetery, Birmingham, Alabama.

Henry Eugene Erwin

In his honor, the United States Air Force established the Henry E. Erwin Outstanding Enlisted Aircrew Member of the Year Award. The library at the Air University, Maxwell Air Force Base, Alabama, is named the Red Erwin Library.

Mrs. Erwin, with the portrait of her husband, painted by artist John Witt, a long time contributor to the Air Force Art Program.

B-29-25-MO 42-65302 was one of 536 Boeing B-29 Superfortresses built by the Glenn L. Martin–Nebraska Company at Fort Crook, Omaha, Nebraska (now, Offutt Air Force Base). Fifty of those were the Block 25 variant. The new B-29 was delivered to the U.S. Army Air Forces on 11 January 1945.

Once assigned to the 314th Bombardment Wing (Very Heavy), the airplane was named City of Los Angeles, in keeping with the wing’s practice of naming the aircraft after cities in the United States. When it arrived at Guam, 42-65302 was identified with a large yellow letter “O” surrounded by a black square, painted on its vertical fin and rudder. The numeral “37” was painted on each side of the fuselage aft of the wings.

29th Bombardment Group (Very Heavy), 314th Bombardment Wing (very Heavy), B-29 Superfortresses at North Field, Guam. Note the “Black Square O” identification symbols. (U.S. Air Force)

The B-29 was the most technologically advanced airplane built up to that time, and required an immense effort by American industry to produce.

The B-29 Superfortress was designed by the Boeing Airplane Company as its Model 345. Produced in three major versions, the B-29, B-29A and B-29B, it was built by Boeing at Wichita, Kansas, and Redmond, Washington; by the Bell Aircraft Corporation at Marietta, Georgia; and the Glenn L. Martin–Nebraska Company at Fort Crook (now Offutt Air Force Base), Omaha, Nebraska. A total of 3,943 Superfortresses were built.

B-29s were normally operated by an 11-man crew: Pilot, copilot, navigator, bombardier, radar bombardier, radio operator, flight engineer, a central fire control gunner, and right, left, and tail gunners.

The B-29 Superfortress was 99 feet, 0 inches (30.175 meters) long with a wingspan of 141 feet, 3 inches (43.053 meters) and an overall height of 27 feet, 9 inches (8.458 meters). It had a wing area of 1,736 square feet (167.28 square meters); The standard B-29 had an empty weight of 74,500 pounds (33,793 kilograms) and gross weight of 120,000 pounds (54,431 kilograms).

A newly-completed B-29 Superfortress at the Martin Bomber Plant. (Nebraska State Historical Society RG3715-2-11)

City of Los Angeles had four air-cooled, supercharged, 3,347.662-cubic-inch-displacement (54.858 liter) Wright Aeronautical Division R-3350-41 (Cyclone 18 787C18BA3) two-row 18-cylinder radial engines with direct fuel injection. The R-3350-41 had a compression ratio of 6.85:1 and required 100/130 aviation gasoline. It was rated at 2,000 horsepower at 2,400 r.p.m. at Sea Level, and 2,200 horsepower at 2,800 r.p.m, for take-off. The engines drove four-bladed Curtiss Electric reversible-pitch propellers with a diameter of 16 feet, 7 inches (5.080 meters), through a 0.35:1 gear reduction. The R-3350-41 was 6 feet, 2.26 inches (1.937 meters) long, 4 feet, 7.78 inches (1.417 meters) in diameter and weighed 2,725 pounds (1,236 kilograms).

The B-29 had a cruise speed of 220 miles per hour (354 kilometers per hour) at 20,000 feet (6,096 meters). Its maximum speed was 306 miles per hour (492 kilometers per hour) at Sea Level, and 357 miles per hour (575 kilometers per hour) at 30,000 feet (9,144 meters). The bomber had a service ceiling of 33,600 feet (10,168 meters). The Superfortress had a fuel capacity of 9,438 gallons (35,727 liters), giving it a maximum range of 3,250 miles (5,230 kilometers) at 25,000 feet (7,620 meters) with 5,000 pound (2,268 kilograms) bomb load.

The B-29 could carry a maximum bomb load of 20,000 pounds (9,072 kilograms). Defensive armament consisted of twelve air-cooled Browning AN-M2 .50-caliber machine guns mounted in four remotely-operated powered turrets, and a tail turret. B-29 variants before Block 25 also had a single M2 20 mm autocannon mounted in the tail.

City of Los Angeles was damaged on a combat mission against Kobe, Japan, in July 1945. Captain Simeral was awarded the Distinguished Flying Cross.

42-65302 survived the war and remained in service with the U.S. Air Force for several more years. It was “reclaimed” at Hill Air Force Base, Utah, 17 November 1953.

This B-29 Superfortress of the 29th Bombardment Group (Very Heavy) on fire over Kobe, Japan, 17 July 1945, MIGHT be City of Los Angeles. (U.S. Air Force)

© 2018, Bryan R. Swopes

9 August 1945

Aviation, , , , , , , , , , , , , , , , , , , ,
Martin-Omaha B-29-35-MO Superfortress 44-27297, Bockscar, at the National Museum of the United States Air Force. The “nose art” was added after the 9 August mission. Note the 509th’s “Circle Arrow” tail insignia. This was replaced by a “Triangle N” marking for the actual bombing mission. (U.S. Air Force)

9 August 1945: Three days after an atomic bomb had been used against the Japanese industrial city of Hiroshima, a second attack was made on Nagasaki. Major Charles W. Sweeney,¹ in command of the Martin-Omaha B-29-35-MO Superfortress 44-27297, named Bockscar, departed Tinian Island in the Marshal Group at 3:47 a.m., and flew to Iwo Jima where it was to rendezvous with two other B-29s, The Great Artiste and The Big Stink, the instrumentation and photographic aircraft for this mission.

Like its sistership, Enola Gay, 44-27297 was a specially modified “Silverplate” B-29. The Silverplate B-29s differed from the standard production bombers in many ways. They were approximately 7,200 pounds (3,266 kilograms) lighter. The bomber carried no armor. Additional fuel tanks were installed in the rear bomb bay. The bomb bay doors were operated by quick-acting pneumatic systems. The bomb release mechanism in the forward bomb bay was replaced by a single-point release as was used in special British Lancaster bombers. A weaponeer’s control station was added to the cockpit to monitor the special bomb systems.

Bockscar had four air-cooled, supercharged, 3,347.662-cubic-inch-displacement (54.858 liter) Wright Aeronautical Division R-3350-41 (Cyclone 18 787C18BA3) two-row 18-cylinder radial engines with direct fuel injection. The R-3350-41 had a compression ratio of 6.85:1 and required 100/130 aviation gasoline. It was rated at 2,000 horsepower at 2,400 r.p.m. at Sea Level, and 2,200 horsepower at 2,800 r.p.m, for take-off. The engines drove four-bladed Curtiss Electric reversible-pitch propellers with a diameter of 16 feet, 8 inches (5.080 meters), through a 0.35:1 gear reduction. The R-3350-41 was 6 feet, 2.26 inches (1.937 meters) long, 4 feet, 7.78 inches (1.417 meters) in diameter and weighed 2,725 pounds (1,236 kilograms).

With the exception of the tail gunner’s position, all defensive armament—four powered remotely operated gun turrets with ten .50-caliber machine guns—were deleted. Their remote sighting positions were also removed. Enola Gay carried 1,000 rounds of ammunition for each of the two remaining Browning AN-M2 .50-caliber machine guns in the tail.

With these changes, the Silverplate B-29s could fly higher and faster than a standard B-29, and the fuel-injected R-3350-41 engines were more reliable. Bockscar had a cruising speed of 220 miles per hour (354 kilometers per hour) and a maximum speed of 365 miles per hour (587 kilometers per hour). Its service ceiling was 31,850 feet (9,708 meters) and its combat radius was 2,900 miles (4,667 kilometers).

Martin-Omaha B-29-35-MO Superfortress 44-27297, Bockscar, in flight. Note "Triangle N" tail code. (U.S. Air Force)
Martin-Omaha B-29-35-MO Superfortress 44-27297, Bockscar, in flight. Note the “Triangle N” tail code. (U.S. Air Force)

44-27297, Victor 7, was assigned to aircraft commander Captain Frederick C. Bock and his crew. Major Sweeney and his crew ordinarily flew The Great Artiste. Sweeney’s B-29 had been the the instrumentation aircraft for the Hiroshima mission and there was not time to remove that equipment and re-install it aboard Bock’s bomber, so the crews switched airplanes. For operational security, Bockscar‘s normal identification was changed from the number 7 on the fuselage to 77. The 509th’s tail code of a circle surrounding a forward-pointing arrow was changed to another unit’s “Triangle N” identification.

All of these last minute changes resulted in confusion in contemporary reports as to which B-29 had actually dropped Fat Man on Nagasaki.

Boeing B-29 crew photo taken Aug. 11, 1945, two days after the Nagasaki mission. Note there is no nose art on the aircraft. (U.S. Air Force photo)
Major Charles W. Sweeney’s B-29 crew. (U.S. Air Force)

In Bockscar‘s forward bomb bay was a 10,213 pound (4,632 kilograms) bomb called Fat Man. This was a completely different and much more complex weapon than the Little Boy (Mark I) atomic bomb dropped by Colonel Paul Tibbet’s Enola Gay on 6 August. The bomb was 12 feet, 8⅜ inches ¹ (3.261 meters) long, 5 feet, ¼ inch ² (1.530 meters) in diameter,

Designated Mark III, the egg-shaped weapon contained a 9.17 centimeter (3.61 inches), 6.15 kilogram (13.6 pound) sphere of Plutonium Pu 239, with a 2.1 centimeter (0.83 inch) hollow cavity at its center. A beryllium neutron initiator was in this cavity. The plutonium sphere was surrounded by a 22.86 centimeter (9.0 inch) diameter uranium tamper with a mass of 108 kilograms (238 pounds). This nuclear assembly was contained in a boron/acrylic shell and surrounded by about 2,390 kilograms (5,269 pounds) of high-explosive, consisting of Composition B and Baratol. The explosives were formed in “lenses” that would direct the force inward in a very precise manner. The purpose was to compress—or implode— the Plutonium to a much greater density, resulting in a “critical mass.”

The Mark III "Fat Man" bomb loaded on its carrier, 8 August 1945.
The Mark III “Fat Man” bomb being loaded onto its carrier, 8 August 1945.

In the conduct of this mission, Major Sweeney made a number of serious errors that nearly caused the mission to fail, and might very well have led to the loss of the bomber and its crew.

Prior to takeoff, the B-29’s crew chief informed Sweeney that a fuel transfer pump was inoperative which made it impossible to transfer 625 gallons (2,366 liters) of fuel from one fuel tank. This meant that nearly 9% of the total fuel load of 7,250 gallons (27,444 liters) was unusable. Chuck Sweeney decided to go anyway.

Next, though under direct orders from the 509th Composite Group commander, Colonel Paul Tibbets, to wait at the rendezvous no more than 15 minutes, when The Big Stink failed to arrive on schedule, Sweeney elected to stay 30 minutes beyond that.

Meanwhile, the two weather reconnaissance B-29s, Enola Gay and Laggin’ Dragon, were over Kokura, the primary target, and the secondary, Nagasaki. Weather over both cities were within the mission parameters.

XX Bomber Command Target Chart for Nagasaki Area. (National Archives)

During the 45 minutes that Sweeney waited at the rendezvous, weather over Kokura had deteriorated. By the time Bockscar arrived overhead, clouds covered the city. The bomber made three attempts to bomb the city over a 50-minute period, but the bombardier was not able to see the target.

Now an hour and twenty minutes behind schedule, Sweeney diverted to the secondary target, Nagasaki. Because of the delays and the unusable fuel as a result of the failed fuel pump, Sweeney reduced engine power to try to conserve fuel during the twenty minute flight to the alternate target. But weather there had also deteriorated.

Sweeney decided that they should bomb through the clouds using radar, but at the last minute, the bombardier was able to see the aim point. The Fat Man was dropped from 30,000 feet (9,144 meters) at 11:01 a.m. After falling for 43 seconds, the atomic bomb detonated at an altitude of 1,950 feet (594 meters). It missed the intended target point by nearly 1.5 miles (2.4 kilometers) and exploded over the Urakami Valley, halfway between the Mitsubishi Steel and Arms Works and the Mitsubishi-Urakami Ordnance Works.

Nagasaki, 9 August 1945, photographed by Joe Kosstatscher, U.S. Navy.
Nagasaki, 9 August 1945, photographed by Joe Kosstatscher, U.S. Navy.

The estimated force of the explosion was 21 kilotons—equivalent to the explosive force of 21,000 tons of TNT (19,050 metric tons)—nearly 20% greater than the Hiroshima bomb. The surrounding hills contained the explosion, protecting a large part of the city. Still, approximately 60% of Nagasaki was destroyed and 70,000 people were killed. By December 1945, at least 80,000 of the city’s 250,000 residents had died.

Atomic cloud rising over nagasaki, japan, 9 August 1945, photographed from Koyagi-jima. (Hiromichi Matsuda)
Pyrocumulus cloud rising over Nagasaki, Japan, approximately 20 minutes after detonation, 9 August 1945, photographed from Koyagi-jima, a small island southwest of Nagasaki. (Hiromichi Matsuda)
Nagasaki. (Bridgeman Images)

Now critically low on fuel and unable to reach the emergency B-29 recovery field on Iwo Jima, Sweeney headed for the airfields of Okinawa. When Bockscar touched down on the runway, one engine quit due to fuel starvation. As they turned off the runway, a second engine ran out of fuel. Charles Sweeney had cut it very, very close.

B-29 44-27297 on Tinian Island, August 1945. The nose art was applied to the airplane after the August 9, 1945 bombing mission. (U.S. Air Force)
Martin-Omaha B-29-35-MO 44-27297 on Tinian Island, August 1945. The nose art was applied to the airplane after the August 9, 1945 bombing mission. (U.S. Air Force)

Five days after the bombing of Nagasaki, the Emperor of Japan—recognizing that his country now faced total destruction—agreed to surrender. World War II was over.

In 1946, Bockscar was placed in storage at Davis-Monthan Army Air Field, Tucson, Arizona. On 26 September 1961, the B-29 was flown to the National Museum of the United States Air Force, Wright-Patterson Air Force Base, Dayton, Ohio, where it remains in the museum’s collection of historic aircraft.

DAYTON, Ohio — Boeing B-29 Superfortress “Bockscar” at the National Museum of the United States Air Force. (U.S. Air Force photo)

¹ The other members of the crew of Bockscar were Captain Charles Donald Albury, co-pilot; Second Lieutenant Frederick John Olivi, co-pilot; Captain James Frederick Van Pelt, Jr., navigator; Captain Kermit King Beahan, bombardier; Master Sergeant John Donald Kuharek, flight engineer; Staff Sergeant Raymond C. Gallagher, assistant flight engineer; Staff Sergeant Edward Kenneth Buckley, radar operator; Sergeant Abe M. Spitzer, radio operator; Sergeant Albert Travis Dehart, tail gunner; Commander Frederick Lincoln (“Dick”) Ashworth, U.S. Navy, weaponeer; Lieutenant Philip M. Barnes, U.S. Navy, assistant weaponeer; First Lieutenant Jacob Beser, radar countermeasures. (Lieutenant Beser also flew aboard Enola Gay, 6 August 1945.)

© 2023, Bryan R. Swopes

8 August 1945

Aviation, , , , , , , , , , , , ,
Fat Man, Nuclear Bomb, Mark III, being prepared at Tinian, Marshall Islands, 8 August 1945. (U.S. Air Force)

“So, the next day, Fat Man, the two armored steel ellipsoids of its ballistic casing bolted together through bathtub fittings to lugs cast into the equatorial segments of the implosion sphere, its boxed tail sprouting radar antennae just as Little Boy’s had done. By 2200 on August 8 it had been loaded into the forward bomb bay of a B-29 named Bockscar after its usual commander, Frederick Bock, but piloted on this occasion by Major Charles W. Sweeney. Sweeney’s primary target was the Kokura Arsenal on the north coast of Kyushu; his secondary was the old Portuguese- and Dutch-influenced port city of Nagasaki, the San Francisco of Japan, home of the country’s largest colony of Christians, where the Mitsubishi torpedoes used at Pearl Harbor had been made.”

—The Making of the Atomic Bomb, by Richard Rhodes, Simon and Schuster, New York, 1986, Chapter 19 at Page 739.

The Mark III “Fat Man” bomb loaded on its carrier, 8 August 1945. (Manhattan Engineer District)

Fat Man was an implosion-type fission bomb, using plutonium (Pu-239) as the nuclear material. It was a very complex device which used 32 precisely-shaped explosive charges surrounding the spherical plutonium-alloy core, detonating with enough force to compress the core to double its normal density. This caused it to reach “critical mass” and the fission chain reaction began.

The Mark III implosion bomb and its trailer are lowered into the pit in preparation for loading aboard Bockscar, 8 August 1945. (U.S. Air Force)
The Mark III implosion bomb and its trailer are lowered into the pit in preparation for loading aboard Bockscar, 8 August 1945. (U.S. Air Force)

The Mark III bomb, unlike the gun-type “Little Boy,” required testing before combat use. The nuclear component of the bomb, called “Gadget,” had been exploded at 05:29:45 a.m., Mountain War Time, 16 July 1945, at the Trinity Site of the Alamogordo Test Range, in the Jornada del Muerta desert of New Mexico. The explosive yield of the detonation was estimated to be equivalent to 20–22,000 tons of TNT.

The fully assembled combat weapon was 12 feet, 8⅜ inches ¹ (3.261 meters) long, 5 feet, ¼ inch ² (1.530 meters) in diameter, and weighed approximately 10,300 pounds (4,672 kilograms).

Rear fuselage of Bockscar, B-29 44-27297, at Tinian. Note the “Triangle N” and “77” codes. The Enola Gay is in the background. (U.S. Air Force)

¹ Overall length, ± ¼ inch

² Overall diameter, ± ⅛ inch

© 2017, Bryan R. Swopes

6 August 1945 (5 August 1945 UTC)

Aviation, , , , , , , , , , , , ,
Silverplate Martin-Omaha B-29-45-MO Superfortress 44-86292, “Dimples 82,” at Tinian, Mariana Islands, August 1945. Note the “Circle Arrow” tail code. (U.S. Air Force)

6 August 1945: At 0245 hours local time (1445 hours, 5 August, UTC), a four-engine, long range heavy bomber of the 509th Composite Group, United States Army Air Forces, took off from North Field on the island of Tinian in the Northern Mariana Islands, on the most secret combat mission of World War II.¹

Colonel Paul Warfield Tibbets, Jr., United States Army Air Forces, Commanding Officer, 509th Composite group, and aircraft commander of the B-29 Superfortress, Enola Gay. (U.S. Air Force)
Colonel Paul Warfield Tibbets, Jr., United States Army Air Corps, Commanding Officer, 509th Composite Group, and aircraft commander of the B-29 Superfortress, Enola Gay. (U.S. Air Force)

The Martin-Omaha B-29-45-MO Superfortress, 44-86292, under the command of Colonel Paul Warfield Tibbets, Jr.,² was carrying Bomb Unit L-11, the first nuclear weapon to be used during war. This was an 8,900-pound (4,037 kilogram) “gun type” fission bomb, the Mark I, code-named Little Boy. It contained 64.15 kilograms (141.42 pounds) of highly-enriched uranium. The bomb was 10 feet, 6 inches (3.2004 meters) long with a diameter of 2 feet, 4 inches (0.711 meters). The gun tube had a bore diameter of 165 millimeters (6.496 inches) and a length of 6 feet (1.8 meters). It weighed approximately 1,000 pounds (454 kilograms).

Diagram of “Little Boy” gun-type uranium fission bomb. (Wikipedia)

The gun fired a hollow uranium projectile, consisting of a stack of nine rings of varying thickness contained within a sheet metal can, and with a 4 inch (10.16 centimeters) inside diameter, against a cylindrical uranium target insert. The projectile was 7 inches (17.78 centimeters) long. The target insert consisted of a stack of six uranium rings with a 1 inch (2.54 centimeter) inside diameter, held in place by a steel rod through the center. It was also 7 inches long, and had an outside diameter of 4 inches. The projectile weighed 38.53 kilograms (84.94 pounds) and the target, 25.6 kilograms (56.44 pounds). When the projectile came in contact with the target, the two completed a “critical mass.” A fission chain reaction resulted, releasing an incredible amount of energy.

Although it was considered to be a very inefficient weapon, it had such a reliable design that it had never been tested. Six Mark I bombs were built, but L-11 was the only one ever to be detonated.

Code named "Little Boy," the Mark I bomb unit L-11, prior to loading aboard Enola Gay, 5 August 1945. (U.S. Air Force)
Code named “Little Boy,” the Mark I bomb unit L-11, prior to loading aboard Enola Gay, 5 August 1945. (U.S. Air Force)

On the morning before the mission, Colonel Tibbets had his mother’s name painted on the nose of the airplane: Enola Gay. He had personally selected this bomber, serial number 44-86292, while he was visiting the Glenn L. Martin Company plant at Bellevue, Nebraska, 9 May 1945. An employee of the plant told him that the airplane had passed its acceptance tests with no faults of any kind. The B-29 was accepted by the Army Air Corps on 15 May and flown to the 509th’s base at Wendover, Utah, by Captain Robert Alvin Lewis, a B-29 aircraft commander who would act as Tibbets’ co-pilot on the atomic bombing mission.

509th Composite Group operations order. (U.S. Air Force)

The B-29 Superfortress was designed by the Boeing Airplane Company as its Model 345. Produced in three versions, the B-29, B-29A and B-29B, it was built by Boeing at Renton, Washington, and Wichita, Kansas; by the Bell Aircraft Corporation at Marietta, Georgia; and the Glenn L. Martin Company at Fort Crook (now Offutt Air Force Base), Omaha, Nebraska. A total of 3,943 Superfortresses were built.

The B-29 was the most technologically advanced airplane built up to that time, and required an immense effort by American industry to produce.

The B-29 Superfortress was 99 feet, 0 inches (30.175 meters) long with a wingspan of 141 feet, 3 inches (43.053 meters) and an overall height of 27 feet, 9 inches (8.458 meters). The standard B-29 had an empty weight of 74,500 pounds (33,793 kilograms) and gross weight of 120,000 pounds (54.431 kilograms).

Enola Gay at Tinian, with crew members.
Enola Gay at Tinian, with crew members.

The 509th Composite Group was equipped with specially modified “Silverplate” B-29s, which differed from the standard production bombers in many ways. They were approximately 7,200 pounds (3,266 kilograms) lighter. The bombers carried no armor. Additional fuel tanks were installed in the rear bomb bay. The bomb bay doors were operated by quick-acting pneumatic systems. The bomb release mechanism in the forward bomb bay was replaced by a single-point release as was used in special Royal Air Force Avro Lancaster bombers. A weaponeer’s control station was added to the cockpit to monitor the special bomb systems.

Colonel Paul W. Tibbets, Jr., waves from the cockpit of the Silverplate Martin-Omaha B-29-45-MO Superfortress Enola Gay, 44-86292, just before starting engines at 02:27 a.m., 6 August 1945. (Sergeant Armen Shamlian, United States Army Air Forces. National Archives and Records Administration)

Enola Gay had four air-cooled, supercharged, 3,347.662-cubic-inch-displacement (54.858 liter) Wright Aeronautical Division R-3350-41 (Cyclone 18 787C18BA3) two-row 18-cylinder radial engines with direct fuel injection. The R-3350-41 had a compression ratio of 6.85:1 and required 100/130 aviation gasoline. It was rated at 2,000 horsepower at 2,400 r.p.m. at Sea Level, and 2,200 horsepower at 2,800 r.p.m, for take-off. The engines drove four-bladed Curtiss Electric reversible-pitch propellers with a diameter of 16 feet, 8 inches (5.080 meters), through a 0.35:1 gear reduction. The R-3350-41 was 6 feet, 2.26 inches (1.937 meters) long, 4 feet, 7.78 inches (1.417 meters) in diameter and weighed 2,725 pounds (1,236 kilograms).

Martin-Omaha B-29 Superfortress 44-86292, “Enola Gay,” at Tinian. (U.S. Air Force)

With the exception of the tail gunner’s position, all defensive armament—four remotely-operated gun turrets with ten .50-caliber machine guns—were deleted. Their remote sighting positions were also removed. Enola Gay carried 1,000 rounds of ammunition for each of the two remaining Browning AN-M2 .50-caliber machine guns in the tail.

With these changes, the Silverplate B-29s could fly higher and faster than a standard B-29, and the new engines were more reliable. Enola Gay had a cruising speed of 220 miles per hour (354 kilometers per hour) and a maximum speed of 365 miles per hour (587 kilometers per hour). Its service ceiling was 31,850 feet (9,708 meters) and its combat radius was 2,900 miles (4,667 kilometers).

XXI Bomber Command Target Chart for Hiroshima Area. (U.S. Strategic Bombing Survey)
XXI Bomber Command Target Chart for Hiroshima. (U.S. Strategic Bombing Survey)

At 09:15:17 a.m., (mission time; 8:15 a.m., local; 2315, 5 August, UTC), Enola Gay, with a True Air Speed of 275 miles per hour (443 kilometers per hour), was at 30,060 feet (9,162 meters) ³ over the Japanese city of Hiroshima, an industrial center on the island of Honshu, with a population of about 340,000 people. The bombardier initiated the automatic release sequence and the the atomic bomb was dropped. It fell for 44.4 seconds and detonated at an altitude of 1,968 feet (600 meters), about 550 feet (168 meters) from the aiming point, the Aioi Bridge over the Ota River.

Immediately after the bomb was released, Colonel Tibbets put his B-29 into a 60° right bank and entered a 155° turn at full power. During the maneuver, which had been calculated to get the airplane as far away from the blast as possible, Enola Gay lost approximately 1,700 feet (518 meters) of altitude. When the bomb detonated, the bomber was about 11 miles (17.7 kilometers) away. Even at this distance, the shock wave struck the bomber with “. . . violent force. Our B-29 trembled under the impact and I gripped the controls tightly to keep us in level flight.” ⁴

A mushroom cloud climbs over the city of Hiroshima, Japan, 2–3 minutes after detonation, 6 August 1945, photographed from Yoshiura, looking southward, by Technical Sergeant George R. Caron, U.S. Army Air Corps, tail gunner of the B-29 Enola Gay, using a Fairchild Camera and Instrument Company K-20 aerial camera with a 6-3/8″ f/4.5, 4″ × 5″ film negative. (U.S. Department of Defense 450806-O-ZZ999-067)
The mushroom cloud rises over Hiroshima, Japan, 2–3 minutes after detonation. Photographed 6,500 meters from hypocenter (Seizo Yamada)
The mushroom cloud rises over Hiroshima, Japan, 2–3 minutes after detonation. Photographed 6,500 meters (4 miles) from hypocenter. (Seizo Yamada)
Pyrocumulus cloud seen from ground level.
Two-tier cloud, 2–5 minutes after detonation, seen from Kaitaichi, 6 miles east of Hiroshima. Photographer unknown. (The Atlantic)
Pyrocumulus cloud rising over Hiroshima. Photographer unknown. (Atomic Heritage Foundation)
A pyrocumulus cloud from the firestorm spreads laterally as it reaches the upper atmosphere. (U.S. Air Force)
A pyrocumulus cloud from the firestorm spreads laterally as it reaches the upper atmosphere. (U.S. Air Force)
Hiroshima photoggraphed by a reconnaissance airplane several hours after the explosion. (U.S. Air Force)
Hiroshima photographed by a reconnaissance airplane several hours after the explosion. (U.S. Air Force)

Ground Zero, the point on the surface directly below the explosion, was the Shima Hospital. The overpressure is estimated to have been 4.5–6.7 tons per square meter. The two-story brick building was completely obliterated. Of the patients, technicians, nurses and doctors inside, nothing remained.

The entrance to Shima Hospital is all the remained following the detonation of the atomic bomb.

The resulting explosion was approximately equivalent in explosive force to the detonation of 16,000 tons (14,515 metric tons) of TNT (16 “kilotons”). An estimated 70,000 people were killed immediately, and another 70,000 were wounded. As many as 160,000 people may have died as a result of the atomic bombing by the end of 1945. More would follow over the next few years.

The shadow of one of the victims of the atomic bomb is etched onto the steps in front of a destroyed building.
The shadow of one of the victims of the atomic bomb is etched onto the steps in front of a destroyed building.

An area of the city with a radius of 1 mile (1.6 kilometers) from the point of detonation (“hypocenter”) was totally destroyed, and combined with the fires that followed, 4.7 square miles (12.17 square kilometers) of the city were destroyed. 69% of all buildings in Hiroshima were completely destroyed and another 6% damaged.

Aerial photograph of Hiroshima, Autumn, 1945. The T-shaped Aioi Bridge in the upper portion of the image was the aiming point of the atomic bomb. (Atomic Archive)
Hiroshima, photographed in the Autumn of 1945. (Atomic Archive)
Col. Tibbets’ B-29, Enola Gay, 44-86292, landing at Tinian Island, 1458, 6 August 1945. Note: “Circle R” identification on tail. (U.S. Air Force)
Martin-Omaha Silverplate B-29 Superfortress 44 86292, Enola Gay, taxis to its hardstand after returning to Tinian, 6 August 1945. (U.S. Air Force)
Martin-Omaha Silverplate B-29 Superfortress 44 86292, Enola Gay, taxis to its hardstand after returning to Tinian, 6 August 1945. (U.S. Air Force)

The bomber was then flown back to Tinian, landing at 1458, after an elapsed time of 12 hours, 13 minutes.

Enola Gay participated in Operation Crossroads, the nuclear weapons test at Bikini Atoll in July 1946. It was transferred to the Smithsonian Institution 30 August 1946 and placed in storage at Davis-Monthan Army Air Field, Tucson, Arizona, 1 September 1946. For decades it sat in storage at different locations around the country, but finally a total restoration was performed. Today, the B-29 is on display at the Steven F. Udvar-Hazy Center, National Air and Space Museum.

Martin-Omaha B-29-45-MO Superfortress 44-86292, Enola Gay, at teh Steven F. Udvar-Hazy Center, Smithsonian Institution National Air and Space Museum.
Martin-Omaha B-29-45-MO Superfortress 44-86292, Enola Gay, at the Steven F. Udvar-Hazy Center, Smithsonian Institution National Air and Space Museum. (Photo by Eric Long, National Air and Space Museum, Smithsonian Institution )

¹ The Hiroshima mission was originally planned for 1 August 1945, but an approaching typhoon caused it to be delayed.

² The other crew members of Enola Gay on 6 August 1945 were Captain Robert Alvin Lewis, co-pilot; Captain Theodore Jerome (“Dutch”) Van Kirk, navigator; Major Thomas Wilson Ferebee, bombardier; Staff Sergeant Wyatt Edwin Duzenbury, flight engineer; Sergeant Robert H. Shumard, assistant flight engineer; Sergeant Joseph Anton Stiborik, radar operator; Private 1st Class Richard H. Nelson, radio operator; Staff Sergeant George Robert Caron, tail gunner. The weaponeer and mission commander was Captain William Sterling (“Deke”) Parsons, United States Navy. 2nd Lieutenant Morris Richard Jeppson was Parsons’ assistant weaponeer. The radar countermeasures officer was 1st Lieutenant Jacob Beser. (Lieutenant Beser also flew aboard Bock’s Car on the Nagasaki mission, 9 August 1945.)

³ Airspeed and altitude from the escape diagram prepared by navigator Captain Theodore J. Van Kirk.

⁴ Colonel Tibbets, quoted in Return of the Enola Gay,  by Paul Tibbets, Mid Coast Marketing, 1998.

© 2023, Bryan R. Swopes