Helpers from Hudson Line up to Castleton Bridge?

Did the line up from the Hudson Div to the bridge ever require helpers?

The line and grade was engineered to avoid the use of helpers and none were ever assigned. But, since you said "ever" I would speculate that there were times in steam days when a train had an engine that was not steaming all that good and could not make the hill. In that event, it is likely that they sent a yard job over from Selkirk or grabbed the Hudson Switcher to give somebody a push. No doubt, even in diesel days a train had units that failed from time to time and so the Hudson Switcher to the rescue. There may have even been times when a westbound doubled the hill taking the head end into Selkirk and coming back for the rear end. During the time I was working on the Hudson Division in the late 50's early 60's I do not recall anyone needing a push or doubling, but I do recall trains "just making it."

However, until the last couple of decades [?] there were two tracks, and the track intended for "uphill" use had a longer run and therefore gentler grades. That track has been abandoned, and all moves now use the steeper one. I don't know if that makes any difference these days. I would suspect not.

The only difference in gradient was the short section where the eastbound downhill track split to bridge the mainline and join Tk. 3 alignment. While the grade is steeper than that on the former westbound uphill track, westbound trains are predominantly empties and well within the tonnage ratings for the power.

Below is a scene from the New York Central's 1925 calendar, by artist Walter L. Greene, showing K3n Pacific No. 3292 (later 4692) racing south along the Hudson River under the recently constructed Castleton Cutoff bridge with the first section of the Century. The green flags indicate a following section. The Greene print was provided by Paul, Jr. and Jan Ubermuth of Connecticut.