Tinian Joint Chiefs
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Also known as Project A, it was a crucial segment of the Manhattan Project aimed at delivering the first nuclear weapons used in the atomic bombings of Hiroshima and Nagasaki during World War II. Established in March 1945, this project comprised 51 personnel from the United States Army, Navy, and civilian sectors, including one British scientist.
Its primary objectives included designing bomb drop cases for aerial delivery, procuring and assembling the bombs, and supporting ballistic testing operations at Wendover Army Airfield in Utah, as well as modifying B-29 bombers to carry the nuclear weapons.
Project Alberta, also known as Project A, was formed in March 1945, absorbing existing groups of Captain William Parsons's Ordnance (O) Division that were working on bomb preparation and delivery. Parsons became the head of Project Alberta, with Ramsey as his scientific and technical deputy, and Ashworth as his operations officer and military alternate.
The Fat Man Assembly Team was under Commander Norris Bradbury and Roger Warner, the Little Boy Assembly under Birch. Philip Morrison was the head of the Pit Crew, Bernard Waldman and Luis Alvarez led the Aerial Observation Team, and Sheldon Dike was in charge of the Aircraft Ordnance Team. Physicists Robert Serber and US Army Captain James F. Nolan, a medical expert, were special consultants.
An additional consultant was Englishman William Penny who had worked on the Manhattan Project. He was later central to the creation of the UK's first atomic bomb, and the development of Britain's thermonuclear weapons during Operation Grapple.
Captain William S. Parsons USN, Rear Admiral William R. Purnell USN, and Brigadier General Thomas F. Farrell became informally known as the "Tinian Joint Chiefs". They had decision-making authority over the nuclear missions.
All personnel had volunteered for this critical mission.
At that time huge Thin Man bomb design posed challenges for delivery, restricting it to specific aircraft like the British Avro Lancaster and the modified American Boeing B-29 Superfortress. Tests carried at the Naval Proving Ground in Dahlgren, Virginia 1943 used a 2.7m scale model Thin Man. The results were disappointing, with the bomb falling into a flat spin, early tests revealed significant issues, prompting a comprehensive testing program.
The Thin Man design was deemed obselecent July 1944, and was replaced by a new gun-type weapon system using enriched uranium called Little Boy.
Establishing Operations on Tinian
Bangometer canister
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In December 1944, plans were made to base operations in the Mariana Islands. After assessing various locations, Tinian was chosen for its suitable airfields. Construction of necessary facilities was overseen by Colonel Elmer E. Kirkpatrick. Four air-conditioned Quonset huts of a type normally used for bombsight repair were provided for laboratory and instrument work. There were five warehouses, a shop building, and assembly, ordnance and administrative buildings.
Ramsey overcame the problem of how to ship through the San Francisco Port of Embarkation. The port wanted a detailed list of what was being sent so it could track it to ensure delivery, but what needed to be shipped was still subject to last-minute changes. He simply designated everything as a "bomb assembly kit". Three of these, one for Little Boy, one for Fat Man and one spare, were shipped to Tinian, which was now codenamed Destination O.
Despite lacking formal orders for an attack, Project Alberta aimed to have the Little Boy ready by August 1, 1945, followed by the Fat Man. During July, multiple combat missions against Japan were conducted using high-explosive Pumpkin bombs. The physical characteristics of Pumpkin bombs closely replicated those of the Fat Man plutonium bomb, with the same ballistic and handling characteristics.
The rest of Project Alberta departed for Tinian following the successful completion of the Trinity test on 16 July. The remainder of the Little Boy assembly team arrived on 22 July, followed by Parsons, Ashworth, Purnell, Farrell and the remainder of the Fat Man assembly, Pit, Observation and Firing teams. The entirety of Project Alberta was assembled on Tinian by 25 July, except for members who were couriers for bomb parts. Nolan arrived on 26 July on the cruiser USS Indianapolis, along with Major Robert Furman and Captain Charles H. O'Brien of the 1st Technical Services Detachment, with the Little Boy assembly and active material. Jesse Kupferberg and Raemer Schreiber arrived by C-54 with the remainder of the Little Boy active material and the plutonium Fat Man pit.
On July 25, orders for the bombing missions were issued, targeting Hiroshima, Kokura, Niigata, and Nagasaki, to be executed as weather permitted.
The Missions
Hiroshima
In the space of a week on Tinian, four B-29s had crashed and burned on the runway. This caused great concern. If a B-29 crashed with a Little Boy, the fire could cook off the explosive and detonate the weapon, with catastrophic consequences. Consideration was given to evacuating the 20,000 personnel on Tinian from the island, but instead it was decided to arm the bomb in flight.
On August 6th 1945 the Enola Gay took off for Hiroshima, carrying the Little Boy bomb. Once armed the weapon was extremely unsafe, with a crash, fire or immersion in water causing a full yield explosion. For this reason 'Deke' Parsons, serving as the weaponeer managed the arming of the bomb during the flight, barehanded in sub-zero temperatures.
The mission proceeded as planned, with the bomb detonating at 8:15 AM local time 580m above Hiroshima with a yield of 15 kilotons. Approximately 70,000 people were killed as a direct result of the blast, with a similar number injured.
Four members of Project Alberta flew on the Hiroshima mission. Luis Alvarez, Harold Agnew and Lawrence H. Johnston were on the instrument plane The Great Artiste, equipped with 'Bangometer' canisters to measure the force of the blast. Bernard Waldman was the camera operator on the observation aircraft Necessary Evil. He was equipped with a special high-speed Fastax movie camera with six seconds of film in order to record the blast. No usable footage was produced, either due to operator error, issues with the equipment, or problems with the film development. It is not clear which.
The only footage of the mushroom cloud was taken by Harold Agnew aboard the Great Artiste, while Robert 'Bob' Caron took the definitive photographs of the cloud from the tail gunner position of the Enola Gay.
Nagasaki
Following the Hiroshima bombing, discussions were held regarding the next target. The Fat Man bomb was loaded aboard the B-29 Bockscar piloted by Major Charles W. Sweeney for the attack on August 9th 1945. Robert Serber was supposed to be on board observation plane 'Big Stink' (later renamed Dave's Dream), but was left behind by the aircraft commander Major James I. Hopkins as he had forgotten his parachute. Since he was the only crew member who knew how to operate the high-speed camera (the whole point of the aircraft's mission), Hopkins had to be instructed by radio from Tinian on its use.
The plutonium bomb did not require arming in flight, but had its safeties removed 30 minutes after the takeoff when Bockscar reached a 1,500m altitude.
It was discovered that the red arming light on the black box connected to Fat Man was lit, indicating that the firing circuit had closed. It took Ashworth and Barnes half an hour to isolate the failed switch that had caused the malfunction and correct the problem.
Despite initial complications, including aircraft malfunctions and weather issues, Bockscar successfully dropped the Fat Man on Nagasaki after diverting from its original target. The weapon detonated 503m above the city with a yield of 21 kilotons. An estimated 40,000 people were killed outright by the blast, with about 25,000 injured.
Conclusion and Aftermath
Project Alberta still had three test assemblies, F101, F102 and F103, and one that was damaged and unserviceable, so new explosive blocks would have to be flown in from Project Camel. Seven B-29s of the 509th Composite Group flew Pumpkin bomb missions on 14 August. Word that Japan had surrendered reached Tinian the following day.
A mission was organised to assess the damage done at Hiroshima and Nagasaki, which included personnel from Project Alberta, the 1st Technical Service Detachment, and the 509th Composite Group. The remainder of Project Alberta began packing up. The unused F101, F102 and F103 assemblies were packed along with spare components and shipped back to Los Alamos. For security reasons, components not returned to the United States were dumped at sea.
Project Alberta's scientific and technical personnel departed Tinian for the United States on 7 September. Project Alberta was then discontinued. Most of its personnel were transferred to the new Z Division, which began moving to Sandia Base.
The horrors of the atomic bombings on Hiroshima and Nagasaki speak for themselves. However, it is worth noting that leading up to the nuclear attacks, Japanese cities had been subjected to intense firebombing. The total number of deaths from the firebombing campaign is estimated to be between 330,000 and 900,000 people, primarily civilians. The single largest attack was the firebombing of Tokyo on March 10th 1945, which killed an estimated 100,000 people and left over a million homeless.
Panoramic view of Hiroshima post attack. The Genbaku Dome was directly under the epicenter.
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