Actually, all of the early F-units had blowers! The first turbocharged EMD was the GP20 (although there were some UP GP9s that sort of introduced the concept).
Also, not all F-cowls were four-axle. Remember the F45/FP45 and the F40C!
“M” stood for “modified”, and was also “m”.
An I cab was the same as an M-cab, but with a rubber “donut” (mmmm… donut…) to "I"solate the cab from engine noise. The designation was eventually replaced with “M”.
OK to sum this up…Corrections welcome.
Domestic Diesels:
A=Cab equipt. unit or it could mean special order(longer frame, usually for bigger fuel tank)
AC=alternator rectifier (instead of DC main generator) on older (2nd gen) units
AC=on newer units AC traction motors SD60 and up
B=Cabless unit (may have a de-commisioned cab)
DD=double duty (8axle units with 2 prime movers)
E=on earlier streamliners-eighteen hundred HP (6axle A-1-A)
E=at the end-EMD rebuild
e=Tier 2 emmisions compliant (ACe are also wide cabs but don’t have the M)
F=on earlier streamliners-fourteen hundred HP (4axle)
F=on later units-full body (cowl unit)
GP=general purpose (4axle)
H=head end power equipt
-H=on the 90MACs means it has the H series prime mover (6000HP 4stroke cycle)
I=isolated “whisper cab”
L=lightweight (may have 6axle A-1-A trucks)
M=north american safty cab or wide cab (without an AC after it implies DC TMs)
M=Morrison Knudsen rebuilt unit (older 2nd gen)
MP=multi purpose (4axle switchers,with tunnel motor style radiator section))
N=nine hundred HP on earlier switchers
P=passenger unit
R=rebuild
RS=road switcher trucks on SW1200RS
S=six hundred HP on earlier switchers
SW=switcher (4axle)
T=twelve hundred HP on earlier switchers units
T=tunnel motors on SD40s & SD45s
u=rebuilt units in canada
V=VMV re built unit
W=wide cabs in Canada (GP40-2W before M became the designator)
W=as in SW,NW -welded frame
X=experimental unit
-2=modular electrical cabinet (much easier to troubleshoot/repair)
-3=advanced electronics / traction controll
Electric units:
A=Asea on the AEM
B=4 axles
C=6 axles
EM=electro motive on the AEM
GM=General Motors
The number represents HP x 1000
Checking my Trackside Guide, I came up the the following:
GMD1 and GMD1m
SW1200RS (Road Switcher modifications)
SD90MAC-H
(I can’t believe CPR has SD90s with Head end power.)
I knew what I was talking about, but I explained it badly!
I assumed that people would understand that the “basic” 20, 30, and 40 series used turbocharged 16 cylinder engines, and was trying to correct the references to the 38 and 39 series, which had been inadvertantly reversed in an earlier post…
My reference to “F” engines was to the 16-645F3 engine as used in the GP50 and SD50 model locomotives. What I was trying to say was that the 16-645E (and 12 and 8 cylinder versions) were the last blower engines built. There were no blower versions of the 645F (which is hardly surprising, given that the 645F was basically a slightly modified 645E running at 950 rpm instead of 900 rpm) and no blower version of the longer stroke 710G was built, possibly because there would be little advantage over the existing 645E engine.
What I wrote was correct, it was, however, misinterpreted.
M636C
There are different letters used with export units, and J and K are among them.
Export Prefixes were
A=streamlined cab unit (either A1A-A1A or Co-Co)
AA=double ended streamlined cab unit otherwise like A
B=reduced clearance streamlined cab unit (for narrow gauge) <
And then there were the electrics. BC Rail had 7 GF6C locomotives for the Tumbler Ridge line and earlier there were the GM6 and GM10 units.
What does the M in AEM7 mean ?
For the AEM7, A=Asea (Swedish firm), EM=Electro-Motive, 7=7000 continuous HP.
GM6C and GM10B, GM=General Motors, 6 or 10=6000 or 10000 continous HP, C=C-C wheel arrangement, B=B-B-B wheel arrangement. Only one of each was built, they were experimentals that were aimed at Conrail, presumably as replacements for E44’s.
OK guys, on the domestic front I added this for H:
-H=on the 90MACs means it has the H series prime mover (6000HP 4stroke cycle)
I’m not sure if that is right. Can someone verify for me?
M636C, I don’t know anything about the export stuff, I’ll take your word for it though. Can I add your export breakdown to my above list? And also before I add your TA & TR correction can you site some domestic examples as I have never heard of either?
Br60103, you brought up the GMDs, where do they fall in with all this? are they export designations? and what were the road switcher modifications the RS represents on the SW1200RS?
Nanimo73 & CSSHEGEWISCH, I’ll add an electric section to my list. This is kind of uncharted territory for me too so please help me out with any corrections.
The GMD1 was built for CN and the Northern Alberta Railway during the late 1950s with A1A trucks for light rail. Later there were given B trucks like these.
http://www.rrpicturearchives.net/showPicture.aspx?id=63193
The SW1200RS have RoadSwitcher trucks.
The SW1200MG (Motor-Generator) are electrics built for Iron Ore of Canada.
http://www.northeast.railfan.net/images/iocc431505.jpg
I’m familiar with the GMD1, but it brings up an interesting question, are they a domestic or export designation? I would consider them Domestic because Canadian designations are the same as the states and EMD is a Canadian co.!!! But it sounds more like an export designation. And I am assumeing it stands for General Motors Diesel.
I’ll correct the RS.
MG=motor generator, an electric unit with a catenary powered motor driving the main generator.
Does that sound good?
And does the F in GF6C still mean full body?