Union Pacific 4837-4849 completed the delivery of UPs 1000-unit SD70M order (Nos. 4000-4999), and the 13 units have a radically MODIFIED nose design that simply cannot be confused with anything else. However, unit 4840 (4-8-4-0, yes 4840!!!) was once personally observed at length by myself surprisingly with a STANDARD nose, though a website photo since shows the unit as HAVING the MODIFIED nose. The question logically arises, then, were there TWO different new UP SD70M units that somehow bore the number 4840?
What you have seen was the phase II cab. The MAC 90 uses the same style of cab with the taller door and rectangular windows. As for the pic, I’ve seen a unit that was unlettered and #ed then having everything added to the photo.
The UP 4840 I saw had a STANDARD phase I cab and nose, NOT phase II, nor the maverick cab that the UP 4840 now running around has.
It could be as simple as UP decided to change the #'s. We had a set of hump switchers in Roseville’s Davis yard that got their #'s changed 3 times in 6 mos…