A Geologist went on the Railway

Not the best shot but you take what you can get in low light conditions... Canadian Pacific had a sizeable fleet of MLW C630, M630 and M636 locomotives.  These were railfan favourites (not so much for the crews) for many years.  Initially they ran across the CP system, but when CP standardized on the SD40 and SD40-2 during the 1970's these units migrated to eastern Canada.  Some would make it as far west as Winnipeg, and a few even went west of there on occasion.   Growing up in western Canada these units were a rarity by the time I became more aware of what was running on the railways.  I saw the occasional C424, S-2 or S-3, but the "Big Alcos" were not something I can recall seeing prior to moving to Winnipeg for university.  These quickly became a favourite, and I was quite happy to see them lurking around the city.   CP retired these units in the early 1990's but reactivated a few when traffic levels required more motive power.  The reactivated units were kept as