I know this is from a couple of months ago but just saw it. You are, AFAIK, incorrect. I lived in Berkeley Heights from 1967 to 1979. While the ETT would show Gladstone Branch trains originating/terminating at Summit, the equipment went through to/from Hoboken on the rear of the "connecting" 6xx/5xx Dover or Morristown (later Denville) train. To the best of my knowledge, there were no Gladstone Branch revenue trains that were scheduled to have their equipment originate or terminate in Summit (exception for work such as when catenary work had diesels substituting on the Dover line but electric ops on the Gladstone Branch).JasW wrote:I believe this only occurred non-rush hour and/or on weekends in this era, but a number of Gladstone Branch trains simply began/ended their run at Summit. They (or at least the eastbound ones) arrived in Summit on the southernmost track against the wall (on the far left in the early 70s photo below), and passengers changed to the eastbound M&E local on the middle track across the platform. Passengers heading west on the Gladstone at these times debarked from the M&E local on the northernmost track (the fully visible one in the photo) and crossed over to the wall track via the station overpass. I think some of the MUs in the Summit mini-yard were Gladstone trains.
Eastbound, Dover train arrived, Gladstone trains followed it in, coupled to rear, carmen hooked everything up, brake test, go. All in under three minutes.
Westbound, train arrived, carmen unhooked everything, Dover train pulled leaving Gladstone cars behind, Gladstone cars then did their tests, and departed. Even less time involved. Unfortunately, once the Arrows and NJT came along, NJT apparently decided this was way too complicated and did away with the joins and separates at Summit.
In the later days, the motors had become sufficiently unreliable that every train had to have at least two motors (four cars) so off-peak trains east of Summit with both Dover and Gladstone cars were always eight cars (I was on a branch train one day with a dead motor; we were so late at Summit that the Dover train had already gone so we just ran extra to Hoboken stopping only as needed to discharge passengers; my one and only time to breeze Newark).