The Special Engineer Detachment (SED) was a U.S. Army program that identified enlisted personnel with technical skills, such as machining, or who had some science education beyond high school, to meet the needs of the Manhattan Project during World War II. SED personnel included the Clinton Engineer Works, Hanford Engineer Works and Los Alamos Laboratory. SED personnel began arriving at Los Alamos in October 1943, and by August 1945, 1,800 worked there. They worked in all areas and activities of the Laboratory, including the Trinity Test, and served overseas on Tinian in support of the atomic bombing of Hiroshima and Nagasaki and in the Pacific with the Operation Crossroads nuclear test series at Bikini Atoll in 1946.
Recruitment With mobilization of American manpower underway due to the needs of the armed forces, the leadership of the Manhattan Project anticipated that they would have difficulty recruiting and retaining skilled technical staff. To meet this need, the Special Engineer Detachment (SED) was formed by the Army Service Forces on 22 May 1943. The personnel were known as "SEDs". The average age of scientific and technical employees at the Los Alamos Laboratory was less than thirty, so many were eligible for the draft under the Selective Training and Service Act of 1940. Although the Manhattan Project attempted to recruit draft-exempt employees, this was not always possible. Deferments were therefore sought, but the authority to grant them lay with local draft boards, and the tight security surrounding the Manhattan Project meant that the boards could not be informed of the reason for the sought deferment. In most cases though, the Selective Service officials were impressed by the Manhattan Project officials' efficiency and determination to minimize the number of requests and granted the deferment. In cases involving an employee at a firm, a check had to be made of all employees to ensure that the person concerned was indeed essential. In February 1944, the War Department banned further deferments for men under the age of 22 in the employ of the War Department or its contractors. This applied to a small number of personnel, who were assigned to the SED upon being drafted into the Army. To meet the Manhattan Project's needs for personnel with technical skills, the Manhattan Project's Personnel Division was assisted by the headquarters of the Army Specialized Training Program (ASTP), which placed its resources at the Manhattan Project's disposal. The ASTP arranged with the universities for security clearances and interviews with ASTP students. The Office of the National Roster of Scientific and Specialized Personnel looked through its files, which contained entries for 597,666 men and women by 1 July 1943, and provided the names, industrial and educational background and military draft status of qualified scientific personnel. Many colleges and universities furnished the names and draft status of graduating students with desired skills. In November 1943, the Manhattan Project secured the services of Samuel T. Arnold, the dean of undergraduates at Brown University, to identify and recruit promising students. He then became the Manhattan Project's liaison officer on personnel matters. Merriam H. Trytten of the National Roster of Scientific and Professional Personnel was attached to the Manhattan Project for several months during which he visited universities and hired scientific personnel.
Authorization Personnel authorizations were handled by the United States Army Corps of Engineers, of which the Manhattan District was a part, until 31 July 1945, when responsibility passed to the headquarters of Army Service Forces. In January 1945, the Corps of Engineers activated the 9812th Technical Service Unit, and most of the enlisted personnel at the Clinton Engineer Works (CEW), the Hanford Engineer Works (HEW) and the Los Alamos Laboratory were transferred to the new unit on 1 February. At Los Alamos, however, the Military Police Corps, Women's Army Corps and service personnel remained part of the 8th Service Command's 4817th Service Command Unit. The demands of the Manhattan Project for specialized skills grew inexorably. From an initial allotment of 62 officers when the Manhattan District was activated on 13 August 1942, the authorization grew to 699 officers on 31 October 1945. The initial authorization of enlisted personnel was 334 on 22 May 1943, and there was a series of increasing authorizations until 31 October 1945, when a peak strength of 6,032 enlisted personnel was authorized. Included in this was an authorization for 75 enlisted women on 15 June 1943, which grew to 370 on 31 December 1945.The Manhattan Project reached peak strength of 4,976 enlisted personnel on 1 November 1945, but this also included Military Police Corps, Women's Army Corps and service personnel as well as scientific and technical staff. During 1946, the Manhattan Project's strength decreased as the demobilization of United States armed forces after World War II progressed, and the authorization was lowered to 2,203 on 9 December 1946. Recruitment continued into 1946, with 1,449 additional personnel requested during the year to replace demobilized personnel, and the Manhattan Project still had 2,326 enlisted personnel on 31 December 1946. The Manhattan District was abolished on 15 August 1947.
Demographics The average Army General Classification Test score of the SEDs was 133, which was the highest of any unit in the Army. About 29 percent had college degrees. Some even had PhDs, but most had been inducted into the Army shortly before or just after they completed their undergraduate studies. All were noncommissioned officers. One-third held the rank of staff sergeant or higher, one-third were sergeants, and one-third were corporals. Normally, men with high Army General Classification Test scores went on to become officers, but SEDs were not permitted to apply to Officer Candidate School (OCS) for security reasons. After the war ended, security was lifted a bit and SEDs were invited to apply for OCS but few accepted. SEDs did not have to undergo basic training, but otherwise they were expected to conform to the usual Army routine of early morning exercises, drills and inspections.
Los Alamos
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