Allen Hazen wrote: ↑Thu Jun 28, 2012 2:14 am
Alcoman--
Could you answer a historical question? There is a string on this (Railroad.net : Alco) forum titled "Odd Canadian GE generators" which has raised the question of when GE's "static excitation" control system debuted: we know that Alco's 251-engined road switchers (introduced 1956) had it, that MLW's 244-engined RS10S (introduced 1956) had it, that later GE-electricaled F-M units (starting1956) had it, but the question is whether it was trailed earlier on smaller units: in particular, on the early units powered by 6-251 engines (S-5 and the narrow-gaugeunitsbuilt by GE for the White Pass and Yukon). Can you tell us?
Very early applications of the GE Static Excitation system by GE itself appear to be:
The second GTEL4500 batch for UP, 1954.
The 6000 hp, four-unit prototype, 1954
The UD18B export Universal model, built only for NdeM, 1956.
The first two appear to predate any use by Alco.
I cannot trace that it was used in any other GE export model. The pre-Universal exports with Alco 12-244 engines all had the Amplidyne system. Amongst the export Universals, the U9, U12 and U18 and their successors, all used the three-field system. The U6B and successors used the split pole system. I think, but I am not sure, that the electronic system made its export debut with the U26C.
The static system was described in AIEE paper 54-190 of 1954 May,
“Static Excitation Control for Diesel-Electric Locomotives”, by S. W. McElhenny and R.M. Smith.
The applicable patent was US2883608 of 1959 April 21, filed 1955 January 03.
Cheers,