This is really for my own railroad. I found that the BN and GM&O/ICG F units are a little more interesting when it came to details when compared to their Californian counterparts (Santa Fe, Espee, Western Pacific, etc.), to me at least. I already have a stash of ICG pictures, but I’m struggling with early BN pictures, ones featuring the units in their original scheme in particular. Any pointers?
These sites might ha v what you are looking for
Burlington Northern was formed in 1970, well after F units were no longer produced. You may want to check roster shots of the BN component railroads, Chicago, Burlington & Quincy (CB&Q) and Great Northern (GN) as well as Spokane, Portland & Seattle (SP&S)
IIRC, quite a few of BN’s F-units were former Northern Pacific units. NP was a little unusual in that they continued to run F-units in dedicated A-B-B-A sets right up to the merger in 1970, long after most railroads had broken up their F-unit sets into individual engines - or had traded them in on newer, 2nd generation engines.
I suspect there is one or more Morning Sun books out there with helpful pictures.
There used to be (still is?) a series of annual BN Motive Power books with good clear roster shot type pics. Older issues have gotten pricey however.
Dave Nelson
There is a LOT of info out there.
For quick and free on the internet, try rrpicturearchives and Fallen Flags.
BN put their freight F’s in the 600-899 range. And their passenger F’s in the 9700-9849 range. Most of the latter number were converted to freight, and got the lower numbers.
Ed