Why only F40PH-2s again?

Ok, I have always wondered why we dont see any other locomotives besides F40PH-2s on the UP West Line. I have always heard that its a weight issue but UPs freight locomotives probably weigh more than the MP36 or F40PHM-2 so im not thinking its not a weight problem. Is there a clearance problem at Oglive? It would be cool to see some variety on that line. I had also recalled something about a F40PHM-2 running on the UP west either last year, or the year before. Anyone know why they dont run them?

Thanks
Colin

It IS a weight problem, but not on the West line. There are bridges on the North and Northwest lines which prohibit the use of MP36s due to their high axle loadings (supposedly they're the heaviest four axle units ever built). Because the west, northwest, and north line use the same pool of motive power, UP just made it simpler by only using F40s. That way there's no possible way for an MP36 to be incidentally defaulted to run on the N/NW lines when no other unit is available.

This is probably as good of a place as any for speculating about changes to Metra's locomotive fleet assignments, once all of the rebuilding in Kentucky is completed...

• As of right now, the units assigned to UP are 127-178, for a total of 51 units.
• The order for rebuilding, as I've been understanding it, are for units 100-149, plus 2 former Amtrak units from the Tennessee Central RR museum, to be Metra 215 and 216. A total of 52 units

Wouldn't that be dandy for the UP?

The freight units can be heavier because they have six axles to spread the weight over. Makes a big difference.