I am sure this has a simple answer:
What do the designations on CN and VIA locomotives–normally found on the cab, under road numbers, mean? I have read online that these are class designations and vary from locomotive type to locomotive type. Is this a Canadian regulation or just something VIA shares with CN due to its original link to the railroad?
You’re correct - VIA class designations reflect CN practice.
The first character indicates the builder - G for EMD/GMDD; E for GE; M for MLW.
The next character indicates the type - F for a road freight locomotive; R for a roadswitcher; P for passenger engine; Y for yard/local; S for shunter. This may be followed by a suffix if the engine is an F-series unit, to indicate whether it is cab equipped (A) or a cabless booster (B).
The next two digits are the nominal horsepower, in hundreds - 30 for 3000 HP, 17 for 1700, etc.*.
The last digit indicates the order in which the locomotive was delivered - a for first order, b for second, etc.
Thus, a 3000-HP SD40 freight engine from CN’s first order is a GF-30a. An 1800-HP RS18 road switcher from CN’s second order is an MR-18b. A 3000-HP VIA F40PH-2 from their first order is a GPA-30a.
Hope this helps!
__*__The one time this has not reflected rated horsepower at time of delivery was in the case of the 2100-series HR616s, which proved incapable of the 3200 HP they were supposed to get when they were assigned road class MF-32, and were derated to 3000 HP by the time CN took delivery.
CP’s system is so much easier, isn’t it?Ex: SD40-2=DRF30f-w Diesel Road Freight, 3000HP, 6th number group-20th number group. (They had a lot of them)
SW1200=ds12 Diesel Switcher 1200 HP
Matthew
So VIA’s P-42s would be a GPA-44a?
Nope, EPA-42a:
Apparently the A/B suffix applies to all passenger engines regardless of whether a B unit was ever actually built in that model; the F40PH-2s and P42s both got A suffixes. An interesting quirk of the system.
Isn’t there another numeral ahead of the horsepower to show that a unit has six axles instead of four? I could swear that I’ve seen some "EF-644"s around here.
There were other modifications: Some of the GTW GP9s were “GRG-17” because they had steam generators (The 1957-built RS-1s were “MRG-10e” for the same reason, though the steam generators didn’t last very long).
SW1200s 1512-1519 were class GR-12za–the one time I’m aware of that a CN class exhausted the entire alphabet.
Whoops. Yes, there is sometimes a prefix to differentiate between six axles and four. It isn’t universal, though.