14,600 hp, four engines, and wonder how many cars it was? Must have been heavy. Goes to show you what a steep grade, going around curves, and wet rails can do to any train.
Regarding my other comment, maybe not all the engines were fully powered or maybe they just pull like crap. But yes this is quite the climb and the struggle.
What kind of flatcars are those immediately following the locos? It looks like the ends of two flatcar platforms resting on a single truck (bogie, for you Brits). ???
Those are articulated spinecars. The articulated design reduces slack in the train, and can simplify switching operations, apparently. It's called a "spine" car because it is mostly just a center sill beam, the "spine," and posts for accepting shipping containers. These can be used for intermodal, or in this case, garbage in containers.
