I’ve noticed that both Kansas City Southern and its subsidiary KCS de Mexico’s loco numbering is consistent. I wonder if both KCS and KCSM use the same numbering system, even though the reporting marks are different. I’m asking because I don’t think there’s any duplication of road numbers between KCS and KCSM. And even though I assumed that KCSM locos would be mostly confined to Mexico, I’ve also noticed that many KCSM locos are running freely on tracks here in the United States, sometimes in midwestern and other states that don’t even border Mexico. I guess KCSM is to KCS what Cotton Belt SSW was to SP.
I would say that your analogy of SP and SSW (Cotton Belt) is probably very accurate, and a good chacterization of the use and utilization of the power of KCSM and KCS in intederchange practices.
Having lived in the KCS operations area their power is apparently, easily interchangable; here on the BNSF Transcon the KCS and KCSM power is not uncommon, but occcasional, also.
Likewise,Feromex units seem to show up around here on the UP’s north-south line infrequently, (KCS,Ks, to Newton, Ks to Wellington,Ks), and beyond.