How come it seems CP Rail uses only 2 or even 1 AC unit on reallly long trains?

Yes, CP’s subsidiary Soo Line runs north from Chicago to Milwaukee and west from there. Also they have Trackage Rights over the UP south towards Louisville over the former C&EI, also east over the NS’ former Conrail Chicago Line to Elkhart, IN and thence Detroit. CP owns the largest share of the Indiana Harbor Belt and also uses the BRC.

Zardoz. the 2 to 1 replacement for AC locomotives is based on continious tractive

SOOOooo, since CP is subject to the same rules of physics as everyone else, shouldn’t the answer to why CP runs so few cabs is simply, “Because they can”?