Construction in the United States Farrell returned to active duty in February 1941 with the rank of
lieutenant colonel to act as then-
Colonel Leslie R. Groves Jr.'s executive officer in the Operations Branch of the Construction Division under the Office of the Office of the
Quartermaster General. At this point, the US Army was about to embark on a national mobilization, and it was the task of the Construction Division of the
Quartermaster Corps to prepare the necessary accommodations and training facilities for the vast army that would be created. The enormous construction program had been dogged by bottlenecks, shortages, delays, spiralling costs, and poor living conditions at the construction sites. Newspapers began publishing accounts charging the Construction Division with incompetence, ineptitude, and inefficiency. Farrell and Groves worked out new, simplified procedures for centralized procurement that provided the flexibility needed to get projects done on time with the accountability that such enormous expenditures demanded. He was awarded the
Legion of Merit for his services.
China-Burma-India In September 1943, the Chief of
Army Service Forces,
Lieutenant General Brehon B. Somervell, created a special India Committee to coordinate activities in the
China-Burma-India theater with those of Army Service Forces back home. Farrell, now a
colonel, was appointed to the committee to oversee construction. The creation of a line of communications from India to China would be the largest engineer undertaking of the war. A number of new units were trained in the United States specifically for the task. In a reorganization later that year, Farrell became Chief Engineer of the
Services of Supply in the China-Burma-India theater. In December he also became head of its Construction Division. Farrell, who was promoted to
brigadier general in January 1944, To bridge the fast-following rivers of northern Burma, Pick and Farrell selected the H-20 Portable Steel Highway Bridge. Production of these had been discontinued in favor of the
Bailey bridge, but Farrell's technical arguments won out and the Corps of Engineers had to reinstate production of the H-20. He also made the decision, controversial in
Washington, to shift the terminus of the oil pipeline from
Calcutta to
Chittagong in order to avoid crossing the
Ganges and
Brahmaputra Rivers, and the dangers of concentrating too many vulnerable installations in the Calcutta area. He was awarded the
Distinguished Service Medal. Groves told Colonel
Kenneth Nichols, the commander of the Manhattan District, that his first choice would be Farrell. Nichols replied: "He would be my first choice too." "Site Y" was the code name for the remote
Los Alamos County, New Mexico facilities that housed the main group of researchers and was responsible for final assembly of the bombs. Farrell was briefed on the physics of the
atomic bomb by
Robert Oppenheimer, and he made several extended tours of the
Alamogordo Bombing and Gunnery Range, which had been chosen as the site for the
Trinity test. On signing a receipt for the
plutonium from
Oak Ridge, Farrell commented: Farrell observed the
Trinity (nuclear test) with Oppenheimer from the control dugout located from the test tower. He initially said to a fellow officer
The long-hairs have let it get away from them. In his report on the test to President Truman on 21 July 1945, Farrell stated: .
William S. Parsons (left),
Rear Admiral William R. Purnell (center), and Brigadier General Thomas F. Farrell (right) Farrell assumed special responsibility for combat operations. He served on the target committee, acting as its chairman when Groves was absent. In July 1945, Farrell arrived on
Guam to coordinate the project with the local commanders. One of his tasks was to brief
General of the Army Douglas MacArthur, which he did on July 26. Farrell was joined by
Rear Admiral William R. Purnell, who represented the Military Liaison Committee, and
Captain William S. Parsons, the commander of
Project Alberta. They became, informally, the "Tinian Joint Chiefs", with decision-making authority over the nuclear mission. Farrell notified Groves that the
Little Boy bomb would be ready for use on or about 3 August, weather permitting. In the space of a week on Tinian, four B-29s crashed and burned on the runway. Parsons became very concerned. If a B-29 crashed with a Little Boy, the fire could cook off the explosive and detonate the weapon, with catastrophic consequences. Parsons raised the possibility of arming the bomb in flight with Farrell, who agreed that it might be a good idea. Farrell asked Parsons if he knew how to do it. "No sir, I don't", Parsons conceded, "but I've got all afternoon to learn." After the
bombing of Hiroshima on 6 August, Farrell, along with Generals
Carl Spaatz,
Nathan Twining,
Barney Giles and
James H. Davies, debriefed Parsons, the aircrews and the observers, and sent Groves a detailed report. Farrell brought forward the date for the next attack because good weather was only predicted until 9 August. He signed the
Fat Man bomb, "To
Hirohito, with love and kisses, T. F. Farrell." The bomb was loaded on the B-29
Bockscar. During pre-flight inspection, a fuel pump was found to be faulty, meaning that of fuel in the bomb bay tank could not be used, although it would have to be carried. Farrell took the difficult decision to continue the mission, in view of the worsening weather. This was only the first of a number of problems that faced the mission crews that day, but the mission was carried out successfully. The surrender of Japan on 14 August precluded further attacks. Groves had already directed Farrell to prepare teams to inspect the effects of the atomic bombs on Hiroshima and Nagasaki, and Farrell had begun assembling the required personnel and equipment. Farrell arrived in Hiroshima by air on 8 September as part of a group, equipped with portable
geiger counters, that was headed by himself, and also included Brigadier General
James B. Newman, Jr from the
US Army Air Forces, Japanese Rear Admiral Masao Tsuzuki, who acted as a translator, and Colonel
Stafford L. Warren, the head of the Manhattan District's Medical Section. They remained in Hiroshima until 14 September and then surveyed Nagasaki from 19 September to 8 October. They were greatly impressed by both the damage done by the atomic bombs, and the extensive Japanese preparations for the
Allied invasion that had been planned prior to the surrender. == Post-war ==