I grew up in Little Falls pretty much next to the tracks. I remember seeing 2 or 3 light engines running and coupled together all the time. They would head west (light) and return a short time later coupled to a train the already had 2 engines on the head end. I don't recall railroad names, engine types etc. My question is what is the grade of that hill to warrant a 5 engine consist? One thing I do remember is the sound of the black U34 engines. They'd pull 4 or 5 car passenger trains. I loved the chugging sound of them. Damn they were deafening........
There was a thread, possibly on NJT or NJState in the Railroad.net family that has covered Great Notch very well with some great stories. I urge you to look for it as it was most informative.
Directly to your inquiry: The line through Great Notch was the Erie's Greenwood Lake Division. Inr the late 50's it became the Erie Lackawanna's Boonton Line. The engine you saw were helpers assigned to get heavy or undepowered trains over the grade either east bound or west bound, whichever was needed when.
