Alcoman wrote:Consider what the letters mean: " M" means modified and "U " means upgraded. In this case, it was both. However, these D&H units were rebuilt by Morrison-Knudsen and given an UPGRADED horsepower from 1600 to 2000 hp, A 12-251 engine and they reworked the TM blower system which amounts to an UPGRADE. Like the D&M units, they were given the letter "U" to signify an UPGRADE regardless how the railroad labeled them. In Dick Steinbrenners book, they are referred to RS-3u in all references.
Good definations, and that all makes sense, except for this part:
Like the D&M units, they were given the letter "U" to signify an UPGRADE regardless how the railroad labeled them.
Regardless of how the railroad labeled them? the railroad is, IMO, the only entity with the authority to call them anything!
(and given the letter "U" by who? that is the question..)
I suppose we could include MK too as an official naming entity.
So MK, and the D&H, have the authority to call them *something*..The definitions of "upgraded" and "modified" are really irrelevant IMO..
Some railroad rebuild locomotives and give them an m, some a u, some a Dash-2 designation, some say Dash-3.
The D&H Alco PA's came back from rebuilding with the designation PA-4.
Railroads are basically free to choose anything they like..the only "official" designation is what the railroad or rebuilder chooses to use.
So we still have nothing official from the D&H concerning RS3u.
current list of sources:
1. D&H paper records that say RS3m, from the poster in the yahoo discussion linked above.
2. The actual D&H 502 clearly labeled RS3M by the D&H itself.
3. D&H classification for "regular" RS3's was ARS-20. D&H classification for the rebuilds was ARS-20m.
1. The Tioga Central Railroad has actually called the 506 a RS3u while it has been in their possession.
2. The book "The American Locomotive Company: A Centennial Remembrance" by Richard T. Steinbrenner (2003) says RS3u in all instances.
The case for RS3m is still a runaway winner.
No known, yet, factual proof to support RS3u from the D&H or MK.
MK called them TE56-4A, which supports neither m or u.