William Sterling "Deak" Parsons (26 November 1901 – 5 December 1953) was an American naval officer who worked as an ordnance expert on the Manhattan Project during World War II. He is best known for being the weaponeer on the Enola Gay, the aircraft which dropped an atomic bomb on Hiroshima, Japan, in 1945. To avoid the possibility of a nuclear explosion if the aircraft crashed and burned on takeoff, he decided to arm the bomb in flight. While the aircraft was en route to Hiroshima, Parsons climbed into the cramped and dark bomb bay, and inserted the powder charge and detonator. He was awarded the Silver Star for his part in the mission.

A 1922 graduate of the United States Naval Academy, Parsons served on a variety of warships beginning with the battleship . He was trained in ordnance and studied ballistics under L. T. E. Thompson at the Naval Proving Ground in Dahlgren, Virginia. In July 1933, Parsons became liaison officer between the Bureau of Ordnance and the Naval Research Laboratory. He became interested in radar and was one of the first to recognize its potential to locate ships and aircraft, and perhaps even track shells in flight. In September 1940, Parsons and Merle Tuve of the National Defense Research Committee began work on the development of the proximity fuze, an invention that was provided to the US by the UK Tizard Mission, a radar-triggered fuze that would explode a shell in the proximity of the target. The fuze, eventually known as the VT (variable time) fuze, Mark 32, went into production in 1942. Parsons was on hand to watch the cruiser shoot down the first enemy aircraft with a VT fuze in the Solomon Islands in January 1943.

In June 1943, Parsons joined the Manhattan Project as Associate Director at the Project Y research laboratory at Los Alamos, New Mexico, under J. Robert Oppenheimer. Parsons became responsible for the ordnance aspects of the project, including the design and testing of the non-nuclear components of nuclear weapons. In a reorganization in 1944, he lost responsibility for the implosion-type fission weapon, but retained that for the design and development of the gun-type fission weapon, which eventually became Little Boy. He was also responsible for the delivery program, codenamed Project Alberta. He watched the Trinity nuclear test from a B-29.

After the war, Parsons was promoted to the rank of rear admiral (United States) without ever having commanded a ship. He participated in Operation Crossroads, the nuclear weapon tests at Bikini Atoll in 1946, and later the Operation Sandstone tests at Enewetak Atoll in 1948. In 1947, he became deputy commander of the Armed Forces Special Weapons Project. He died of a heart attack in 1953.

Early life

William Sterling Parsons was born in Chicago, Illinois, on 26 November 1901, the oldest of three children of a lawyer, Harry Robert Parsons, and his wife Clara, née Doolittle. Clara was the granddaughter of James Rood Doolittle, who served as US Senator from Wisconsin between 1857 and 1869, and of Joel Aldrich Matteson, Governor of Illinois from 1853 to 1857.

In 1909, the family moved to Fort Sumner, New Mexico, where William learned to speak fluent Spanish. He attended the local schools in Fort Sumner and was home schooled by his mother for a time. He commenced at Santa Rosa High School, where his mother taught English and Spanish, rapidly advancing through three years in just one. In 1917 he attended Fort Sumner High School, from which he graduated in 1918.

thumb|160px|Parsons as a midshipman at the United States Naval Academy (1922)

In 1917 Parsons traveled to Roswell, New Mexico, to take the United States Naval Academy exam for one of the appointments by Senator Andrieus A. Jones. He was only an alternate, but passed the exam while more favored candidates did not, and received the appointment. As he was only 16, two years younger than most candidates, he was shorter and lighter than the physical standards called for, but managed to convince the examining board to admit him anyway. He entered the Naval Academy at Annapolis, Maryland, in 1918, and eventually graduated 48th out of 539 in the class of 1922, in which Hyman G. Rickover graduated 107th. At the time, it was customary for midshipmen to acquire nicknames, and Parsons was called "Deacon", a play on his last name. This became shortened to "Deak".

Ordnance

On graduating in June 1922, Parsons was commissioned as an ensign and posted to the battleship ,

In July 1933, Parsons became liaison officer between the Bureau of Ordnance and the Naval Research Laboratory (NRL) in Washington, D.C. but there were numerous technical difficulties with this. The radar set had to be made small enough to fit inside a shell, and its glass vacuum tubes had to first withstand the 20,000 g force of being fired from a gun, and then 500 rotations per second in flight. A special Section T of NDRC was created, chaired by Tuve, with Parsons as special assistant to Bush and liaison between NDRC and BuOrd.

On 29 January 1942, Parsons reported to Blandy that a batch of fifty proximity fuzes from the pilot production plant had been test fired, and 26 of them had exploded correctly. Blandy therefore ordered full-scale production to begin. In April 1942, Bush, now the Director of the Office of Scientific Research and Development (OSRD), placed the project directly under OSRD. The research effort remained under Tuve but moved to the Johns Hopkins University's Applied Physics Laboratory (APL), where Parsons was BuOrd's representative. In August 1942, a live firing test was conducted with the newly commissioned cruiser . Three pilotless drones were shot down in succession.

Parsons had the new proximity fuzes, now known as VT (variable time) fuze, Mark 32, flown to the Mare Island Navy Yard, where they were mated with 5"/38 caliber gun rounds. Some 5,000 of them were then shipped to the South Pacific. Parsons flew there himself, where he met with Admiral William F. Halsey at his headquarters in Nouméa. He arranged for Parsons to take VT fuzes out with him on the cruiser . On 6 January 1943, Helena was part of a cruiser force that bombarded Munda in the Solomon Islands. On the return trip, the cruisers were attacked by four Aichi D3A (Val) dive bombers. Helena fired at one with a VT fuze. It exploded close to the aircraft, which crashed into the sea.

To preserve the secrecy of the weapon, its use was initially permitted only over water, where a dud round could not fall into enemy hands. In late 1943, the Army obtained permission for it to be used over land. It proved particularly effective against the V-1 flying bomb over England, and later Antwerp in 1944. The use of a version fired from howitzers against ground targets was authorized in response to the German Ardennes Offensive in December 1944, with deadly effect. By the end of 1944, VT fuzes were coming off the production lines at the rate of 40,000 per day.

Manhattan Project

Project Y

thumb|right|Captain Parsons on Tinian in 1945

Parsons returned to Dahlgren in March 1943. Around this time, a research laboratory was established at Los Alamos, New Mexico, under the direction of J. Robert Oppenheimer as Project Y, which was part of the Manhattan Project, the top-secret effort to develop an atomic bomb. The creation of a practical weapon would necessarily require an expert in ordnance, and Oppenheimer tentatively penciled in Tolman for the role, but getting him released from OSRD was another matter. Until then, Oppenheimer had to do the job himself. In May 1943, the Manhattan Project's director, Brigadier General Leslie R. Groves, took up the matter with the Military Policy Committee, the high-level committee that oversaw the Manhattan Project. It consisted of Vannevar Bush as its chairman, Brigadier General Wilhelm D. Styer who represented the Army, and Rear Admiral William R. Purnell as the Navy's representative.

Groves told them that he was looking for someone with "a sound understanding of both practical and theoretical ordnance – high explosives, guns and fusing – a wide acquaintance and an excellent reputation among military ordnance people and an ability to gain their support; a reasonably broad background in scientific development; and an ability to attract and hold the respect of scientists." He said that a military officer would be his ideal, as the job might involve planning and coordinating the use of the bomb, but added that he knew of no Army officer who fit the bill. Bush then suggested Parsons, a nomination supported by Purnell. The next morning, Parsons received a phone call from Purnell, ordering him to report to Admiral King, who was now the commander in chief, US Fleet (Cominch). In a terse ten-minute meeting, King briefed Parsons on the Project, which he said had his full backing. That afternoon, Parsons met with Groves, who quickly sized him up as the right man for the job.

left|thumb|"Thin Man" plutonium gun test casings at [[Muroc Army Airfield. In the background, casing designs for "Fat Man" bombs can be seen as well.]]

Parsons was relieved of his duties at Dahlgren and officially assigned to Admiral King's Cominch staff on 1 June 1943, with a promotion to the rank of captain. On 15 June 1943, he arrived at Los Alamos as Associate Director. Parsons would be Oppenheimer's second in command. Parsons and his family moved into one of the houses on "Bathtub Row" that had formerly belonged to the headmaster and staff of the Los Alamos Ranch School. Bathtub Row, so-called because the houses were the only ones at Los Alamos with bathtubs, was the most prestigious address at Los Alamos. Parsons became Oppenheimer's next-door neighbor, and in fact his house was slightly larger, because Parsons had two children and Oppenheimer, at this point, had only one. With two school-age children, Parsons took a keen interest in the construction of the Central School at Los Alamos, and became president of the school board. Instead of the temporary two-story structure that Groves had envisioned in the interest of economy and not misusing the project's high priorities for labor and materials, Parsons had a well-built, modern, single-story school constructed. On seeing the result, Groves said: "I'll hold you personally responsible for this, Parsons."

Oppenheimer had already recruited key people for Parsons's Ordnance Division. Edwin McMillan was a physicist who headed the Proving Ground Group. His first task was to establish the ordnance test area. Later he became Parsons's deputy for the gun-type fission weapon. Charles Critchfield, a mathematical physicist with ordnance experience at the Army's Aberdeen Proving Ground, was in charge of the Target, Projectile and Source Group. Kenneth Bainbridge arrived in August to take charge of the Instrumentation Group. Parsons recruited Robert Brode from the proximity fuze project to become head of the Fuze Development Group. Joseph Hirschfelder was brought in as an expert on internal ballistics, and headed the Interior Ballistics Group. From the beginning, Parsons wanted Norman Ramsey as the head of the delivery group. Edward L. Bowles, the scientific adviser to the Secretary of War, Henry L. Stimson, was reluctant to part with Ramsey, but gave way under pressure from Groves, Tolman and Bush. Perhaps the most controversial group head would be Seth Neddermeyer, the head of the Implosion Experimentation Group; for the time being, Parsons accorded a relatively low priority to this work. He also recruited Hazel Greenbacker as his secretary.

thumb|right|Parsons (right) supervises loading of [[Little Boy into the bomb bay of Enola Gay.]]

Groves, among others, felt that Parsons had a tendency to fill positions with naval officers. There was some aspect of service parochialism, and Parsons believed that involvement in the Manhattan Project would be important for the future of the Navy, but it was also due to the difficulty of getting highly skilled people from any source in wartime. Parsons simply found it easiest to get them through Navy channels. Lieutenant Commander Norris Bradbury said that he did not wish to join Project Y, but was soon on his way to Los Alamos anyway. Parsons recruited Commander Francis Birch, who replaced McMillan at Anchor Ranch. Commander Frederick Ashworth was a naval ordnance officer and aviator who was senior aviator at Dahlgren when he was brought in to work on the delivery side. By the end of the war, there were 41 Naval officers at Los Alamos.

Over the next few months, Parsons's division designed the gun-type plutonium weapon, codenamed Thin Man. It was assumed that a uranium-235 weapon would be similar in nature. Hirschfelder's group considered various designs, and evaluated different propellants. The ordnance test area, which became known as "Anchor Ranch", was established on a nearby ranch, where Parsons conducted test firings with a 3-inch anti-aircraft gun. Work on implosion lagged by comparison, but this was not initially a major concern, because it was expected that the gun-type would work with both uranium and plutonium. However, Oppenheimer, Groves and Parsons lobbied Purnell and Tolman to get John von Neumann to have a look at the problem. Von Neumann suggested the use of shaped charges to initiate implosion.

thumb|left|A gun-type nuclear bomb|alt=Diagram of bomb showing the gun barrel, hollow uranium "bullet" and cylindrical "target"

Oppenheimer considered that there was a "reciprocal lack of confidence" between Parsons and Neddermeyer, and in October 1943 he brought in George Kistiakowsky, who began a new attack on the implosion design. and was promoted to the wartime rank of commodore on 10 August 1945. He was survived by his father, brother, half-brother and sister, as well as his wife Martha and daughters Peggy and Clare.

The Rear Admiral William S. Parsons Award for Scientific and Technical Progress was established by the Navy in his memory. It is awarded "to a Navy or Marine Corps officer, enlisted person, or civilian who has made an outstanding contribution in any field of science that has furthered the development and progress of the Navy or Marine Corps." The Forrest Sherman-class destroyer was named in his honor. Her keel was laid down by Ingalls Shipbuilding of Pascagoula, Mississippi, on 17 June 1957, and was launched by his widow Martha on 17 August 1958. When it was rechristened as a guided missile destroyer (DDG-33) in 1967, Clare, now a naval officer herself, represented her family. Parsons was decommissioned on 19 November 1982, stricken from the Navy list on 1 December 1984, and disposed of as a target on 25 April 1989. The Deak Parsons Center, headquarters of Afloat Training Group, Atlantic, in Norfolk, Virginia, was also named for him. Parsons's portrait is among a series of paintings related to Operation Crossroads. His papers are in the Naval Historical Center in Washington, D.C.

Parsons was depicted in the following films or television works:

  • The Beginning or the End (1947) by Warner Anderson
  • Above and Beyond (1952) by Larry Gates
  • Enola Gay: The Men, the Mission, the Atomic Bomb (1980) by Robert Pine
  • Day One (1989) by Dee McCafferty
  • Fat Man and Little Boy (1989) by Michael Brockman
  • Hiroshima (1995) by Gary Reineke

Notes

References

  • Interview with Peggy Parsons Bowditch, daughter of Deak Parsons, about her father and growing up in Los Alamos Voices of the Manhattan Project
  • Arlington National Cemetery