CN Locomotive identification

[power58]

Have noticed under CN 2876 number EF-644p, other locos such as CN 2302 has EF-644i, CN 2010 has EF-640h is there a way to decode this system ?

[SD70M-2Dude]

Here's a link to the CNR Historical Association's excellent explanation of CN's (and VIA Rail's) diesel classification scheme.  It has been in use since the 1950s and was originally an extension of the steam locomotive classification scheme.

http://www.cnrha.ca/node/285

In this scheme an EF-644p is a General Electric Freight unit with 6 axles producing 4400 horsepower from the 16th order of such locomotives.  Note that the scheme does not differentiate between AC & DC units, or between different models from the same builder producing the same horsepower; class EF-644 includes Dash-9's, ES44DC's and ES44AC's.

In my experience most train crews on the CN don't use it anymore (not sure about the mechanical dept), instead we refer to different locomotive types based on their number series, we would simply call an ES44AC a "2800" or "2900".  But a few old heads still refer to units based on this classification system, and most new or repainted units come with the initialling. 

[power58]

Thank You for the information, great stuff. I would not have thought CNR had a Historical Assosiation, it is as you say a very good site.