E7A Verses EA7 - Nomenclature Differences - No Practical Difference - Inquiry

Discussion in 'Diesel General' started by FriscoMKT, Aug 30, 2010.

  1. FriscoMKT

    FriscoMKT Member

    I have recognized that there is mention about an EA7.

    What is different about it and an E7A?
     
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  2. Iantha_Branch

    Iantha_Branch Member

    Never head of an EA7.

    Possibly it could be a typo of E7A, E7 A-unit.
     
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  3. TAG1014 (Tom Galbraith RIP 7/15/2020)

    TAG1014 (Tom Galbraith RIP 7/15/2020) Passed Away July 15, 2020 Frisco.org Supporter

    EA7 is the actual technical name of the engine commonly called E7.

    I think EA7 is the EMD in-house name.

    Tom
     
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  4. gstout

    gstout Member Frisco.org Supporter

    The previous comment is correct.

    I ran across references to "EA6," EA7" in researching previous projects. That term appears to have disappeared when EMD began producing the E8 and later E9.

    For any practical purposes like modeling, general discussion, there is no difference.

    Greg Stout
     
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  5. TAG1014 (Tom Galbraith RIP 7/15/2020)

    TAG1014 (Tom Galbraith RIP 7/15/2020) Passed Away July 15, 2020 Frisco.org Supporter

    Dr. Louis Marre painstakingly called them EA7s in his Frisco Diesel Power book!

    Tom
     
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  6. klrwhizkid

    klrwhizkid Administrator Staff Member Administrator Frisco.org Supporter

    Dr. Marre, on pages 66 - 71 of Frisco Diesel Power "painstakingly" refers to the same units as EA7s and E7s interchangeably.

    Dr. Marre, on pages 39 - 41 of Frisco in Color, refers to the same units as E7s and E7As.

    Joe Collias, in Frisco Power, pages 225 - 234 refer to these units as E-7s and E7As.

    I have found other references for other railroads that seem to use the terms EA7, E7, and E7A interchangeably as well.

    Tom undoubtedly holds the winning hand!
     
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  7. TAG1014 (Tom Galbraith RIP 7/15/2020)

    TAG1014 (Tom Galbraith RIP 7/15/2020) Passed Away July 15, 2020 Frisco.org Supporter

    When I think of any of those E7, E7A, EA7, I think of the Texas Special.

    Any other E7's are just plain Janes. :)

    Tom
     
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  8. FriscoMKT

    FriscoMKT Member

    Thanks for the information.

    I never knew that the E7s were called EA7s by EMD.
     
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  9. FriscoFriend (Bob Hoover RIP 4/12/2018)

    FriscoFriend (Bob Hoover RIP 4/12/2018) Passed Away April 12, 2018 Frisco.org Supporter

    I am going to throw a different theory into the ring here.

    One must remember that there were both A and B units in the E unit lines.

    The Frisco just never bought B units. Alco referred to their units in that manner, or at least historians did, and the Frisco did buy FA-1s and FB-1s.

    Therefore, it is possible that historians like Dr. Marre might have taken to referring to them in that manner.
     
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  10. meteor910

    meteor910 2009 Engineer of the Year Staff Member Frisco.org Supporter

    This is much ado about nothing.

    Whoever made the point above that EA6 or EA7 was just EMD's (really EMC's) early designations for their successive E-units was correct.

    The first formal "E-unit" with the familiar streamlined body was the EA (6 units) and EB (six units) produced by EMC for the B&O Railroad, around 1937. They were 1800 HP, using two 12-cylinder Winton 201A engines, each, and ran in A-B sets, 3600HP.

    As additional models were produced for and bought by other roads, with some improvements each time, they were called EA1, EB1, EA2, EB2, EA3, EB3, EA6, EB6, etc. by EMC/EMD.

    Later on, probably during the reign of the E7, somebody decided it would make more sense - and be consistent with the F-unit designations, to call them E7A, E7B, etc. A good move.

    That is it, forget about it. An EA1 was the same as an E1A, and so on.

    Ken
     
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