1 Reply Latest reply on May 14, 2019 8:05 AM by Jason Atkinson

    WW2 Military Occupational Specialty

    michael wagner Wayfarer

      Could someone assist?  My Dad's Separation Qualification Record form listed his occupation in WW2 as:


      Power Plant Oper. 846 the description was "Maintained 4 and 6 cylinder engines on 40MM and 90MM Antiaircraft artillery gun.


      Also, his basic training I believe was at Camp Edwards in Mass.  The description of his training was CAC 521.  I believe CAC stood for Coast Artillery Command?


      I'm trying to figure out more concretely what he would have done in maintaining the gun.  He had a military drivers licence for 1 1/4 to 1 1/2 and 2 1/4 ton cargo trucks.  So he could have driven around with the gun in tow?

        • Re: WW2 Military Occupational Specialty
          Jason Atkinson Ranger

          Dear Mr. Wagner,


          Thank you for posting your request on History Hub!

          We located the following job description in Technical Manual 12-427-- Military Occupational Classification of Enlisted Personnel, published by the War Department on 12 July 1944, pages 108-109.




          Operates a mobile power generator which produces electric power for the operation of various machines or for the lighting of an installation.


          Services, lubricates, and makes minor repairs to the engine, using screw drivers, wrenches, and grease guns. Starts engine and regulates engine speed by controlling supply of gasoline. Reads voltmeter and regulates voltage output of generator by a hand controlled rheostat. Connects generator by cables to equipment or machinery for which it supplies power. Keeps an operations log. May drive light or heavy truck.


          Because power generators were typically sizable pieces of equipment, the operators often needed to use a truck to move them around, which would explain why he had a military driver’s license. 

          As indicated in Tables of Organization and Equipment (TOEs), Portable Power Generators Operators were assigned to a wide variety of units, such as the Antiaircraft Artillery Automatic Weapons Battery, Mobile.  While you did not specify what unit your father was assigned to after his training, it may have been a unit such as the one mentioned above or another type of anti-aircraft unit. While portable power generators in general could be used for any purpose requiring electricity, the job description you quote suggests that he worked with generators that provided power directly to 90 mm and 40 mm anti-aircraft weapon systems.  For example, during World War II, the primary 90 mm anti-aircraft gun used by the U.S. Army was the M1 and its subsequent versions, the M1A1 and M2. Features such as power traverse, electric rammers, and electronic fire control computers were added to the guns with each new version. Also, the guns sometimes were used in conjunction with searchlights and radars. All of these would have required electrical power provided by portable generators.

          The National Archives and Records Administration has custody of Army records from the World War II time period, such as technical manuals, field manuals, and unit files that might provide further insight into your questions. For access to these records, please contact the National Archives at College Park - Textual Reference (RDT2) via email at archives2reference@nara.govAn Army institution which may be of assistance is the U.S. Army Center for Military History.


          We hope this information is helpful.  Best of luck with your research!


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