"Extra 2200 South" had an article on the U23B and U23C by Bob Carman and Bill Peterson in issue#75. (Cover date April-May-June 1982, but since therre are news items and photos from June 82, it may have actually been published a bit later.)
In the "Spec Profile" it says that DC/DC U23B had 581 generators (specifically, GT581D or GT581F1) and that AC/DC units had GTA11 (specifically GTA11A1 or GTA11C1).
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QUESTION: Were there any other variants?
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For DC: The GT581 was catalogued for Alcos of 1600 to 2400 hp, so would be the obvious generator of choice for a 2250 hp 4-motor unit with an engine speed comparable to that of the Alco engines. A certain number of Alcos in the 2000 to 2400 hp range, however, were built with generators from trade-ins: 566 (from PA/PB, used in-- for example-- some LI C420 and NYC RS32) or 564 (from FA/FB-1 and RS-2, used in other NYC RS32 and in GB&W C424). I believe the GT581 was a derivative of the GT564, of-- I assume-- similar dimensions. So there should have been no TECHNICAL reason why GE couldn't have used it in some U23B, and a fair number of DC/DC U23B went to impecunious customers who may well have had early Alcos to trade in.
QUESTION: does anyone know of an application of the GT564 generator in a U23B?
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For AC/DC: Early GE locomotives with AC/DC transmission used the (overengineered) GTA9. The cheaper GTA11 seems to have replaced it in production around 1969: EL's first order of U33C (built in 1968) had GTA9, and their second (built in 1969) had GTA11. Most AC/DC U23B were built in 1972 or later, but the first order-- C&O 2300-2329, GE construction numbers 37228-37257-- were built in September and October 1969. Probably GTA11, but
QUESTION: Does anyone know for sure?
--
((There are inaccuracies on this sort of thing in published railfan literature and internet rosters; I have a vague ambition of trying to sort the details out for GE models I am particularly fond of!))
In the "Spec Profile" it says that DC/DC U23B had 581 generators (specifically, GT581D or GT581F1) and that AC/DC units had GTA11 (specifically GTA11A1 or GTA11C1).
--
QUESTION: Were there any other variants?
--
For DC: The GT581 was catalogued for Alcos of 1600 to 2400 hp, so would be the obvious generator of choice for a 2250 hp 4-motor unit with an engine speed comparable to that of the Alco engines. A certain number of Alcos in the 2000 to 2400 hp range, however, were built with generators from trade-ins: 566 (from PA/PB, used in-- for example-- some LI C420 and NYC RS32) or 564 (from FA/FB-1 and RS-2, used in other NYC RS32 and in GB&W C424). I believe the GT581 was a derivative of the GT564, of-- I assume-- similar dimensions. So there should have been no TECHNICAL reason why GE couldn't have used it in some U23B, and a fair number of DC/DC U23B went to impecunious customers who may well have had early Alcos to trade in.
QUESTION: does anyone know of an application of the GT564 generator in a U23B?
--
For AC/DC: Early GE locomotives with AC/DC transmission used the (overengineered) GTA9. The cheaper GTA11 seems to have replaced it in production around 1969: EL's first order of U33C (built in 1968) had GTA9, and their second (built in 1969) had GTA11. Most AC/DC U23B were built in 1972 or later, but the first order-- C&O 2300-2329, GE construction numbers 37228-37257-- were built in September and October 1969. Probably GTA11, but
QUESTION: Does anyone know for sure?
--
((There are inaccuracies on this sort of thing in published railfan literature and internet rosters; I have a vague ambition of trying to sort the details out for GE models I am particularly fond of!))