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Special Engineer Detachment

Special Engineer Detachment is a engineering topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Special Engineer Detachment rather than just read about it. In short: 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.

Special Engineer Detachment — main illustration
Special Engineer Detachment — illustration

Key takeaways

  • Special Engineer Detachment belongs to engineering; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Special Engineer Detachment to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Special Engineer Detachment from memory before moving on to harder problems.

Reference excerpt

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

… excerpt ends here. Continue reading the full article.

Illustrations

Special Engineer Detachment illustration
Special Engineer Detachment: The Special Engineer Detachment (SED) at Los Alamos in 1945
The Special Engineer Detachment (SED) at Los Alamos in 1945
Special Engineer Detachment: SEDs at the Army PX at Oak Ridge
SEDs at the Army PX at Oak Ridge
Special Engineer Detachment: Major General Leslie R. Groves Jr. addresses the troops outside of the Castle at Oak Ridge on 29 August 1945.
Major General Leslie R. Groves Jr. addresses the troops outside of the Castle at Oak Ridge on 29 August 1945.
Special Engineer Detachment: Special Engineering Barracks at Oak Ridge
Special Engineering Barracks at Oak Ridge

Worked examples

Example 1 — a first encounter with Special Engineer Detachment

Start with the simplest possible case. Write down what Special Engineer Detachment claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In engineering, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Special Engineer Detachment before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Special Engineer Detachment ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Special Engineer Detachment

In research
Special Engineer Detachment appears in engineering research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Special Engineer Detachment in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Special Engineer Detachment is common in secondary-school and first-year university syllabi. It links to neighbouring topics Manhattan Project, so understanding it makes those chapters shorter.
In everyday life
Look for Special Engineer Detachment outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Special Engineer Detachment in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Special Engineer Detachment means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Special Engineer Detachment out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Special Engineer Detachment in simple terms?

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.

Why does Special Engineer Detachment matter?

Because it connects several engineering ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Special Engineer Detachment?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Special Engineer Detachment.

Tags

  • Manhattan Project

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