I used to run over the cut off back in the early to mid 70's as a PC Fireman and Engineer. I was promoted in March of 1974 and bid for and held the H-618 Enola pool crew out of Jersey city N.J. for a year or so. The Trenton cut off at that time was a double track signaled/cab signaled electrified freight main line with a 40 mph speed limit. Around 1974 the PC rebuilt most of the eastbound no. one track with welded rail and raised the speed limit to 50 mph. Morrisville yard anchored the cut off on the east end.The Trenton Branch, it's official name at this time, was part of the Harrisburg division. Milepost 46.O was Morris tower, with milepost 0.0 designated GLEN int The west end had two exit points, DALE at MP 0.7 the entrance to the P and T branch, which took you down to Thorndale proper and the entrance to the Philly-Harrisburgh main line and GLEN at MP 0.0 which let you out on the main line east of Thorndale. Both interlockings were controlled by Thorndale tower which officially was designated as THORN.
Traffic during this time period consisted of very heavy ore, coal and coke movements feeding the gigantic U.S Steel Fairless works which at the time had 11,000 employees and was located just southeast of Morrisville yard connected by a huge double track concrete brige spanning the four track New York- Wash PC mainline. The mill also produced a great deal of outbound finished steel products. Iron ore boats originating in Venezuela off loaded at Fairless works producing many 100 car Ore extras destined for the U.S. Steel mill in Saxonburg Pa. and Bethlehem Steel in Bethlehem PA routed Morrisville yard and up the Bel-Del railroad.On any given day the cut off was host to the piggyback trains TV-11, TV-12, TV-3, TV-2,TV-20, TV9m,TV-10a, TV-19,TV-79 and TV-4. If the cutoff was plugged some of these trains were run via Philly and sent up or down the Main line. If TV-12 had livestock for Cross brothers meatpacking it ran via Philly.By and large most of the westbound trains had the 72 car limit and S office in Philly was averse to putting helpers on these trains out of Zoo to get them up and over the main line's grades due to fears of jacknifing.
Back to the cut off, some of the manifests trains operating were AST-4 which usually ran in two or more sections during weekdays, EV-4,CG-8,CG-6,CNY-4,CG-2, SWC-1,P-5,NJC-1(autoracks Metuchen-Linden) VE-1, PR-7 and PR-9. Tuesdays seemed the busy traffic day of the week and it was possible to have 40 plus trains traverse the cut off in a 24 hour period. Power for these trains usually would be GG-1s,E-44's and E-33's and the two GM/EMD experimental electrics.Any of these trains could run with SD-45/SD40 combos, ALCO Century series, GP-40/GP-35's or any variation of GE U-boat models. The VE-1/EV-4 were two Selkirk -Morrisville-Enola heavy thru freights that usually ran with solid U-boat consists due to Selkirk being the system GE U -boat shop.The cut off had no intermediate interlockings though NEST tower in Earnest yard was a block station manned 24 hours a day and the place to run around broken down freights against the current of traffic in emergencies. It was a pretty simple railroad to run over with a few grade crossings and one stiff grade eastbound coming into Morrisvillle and a steady westbound climb out of Neshaminy and west of Earnest up to GLEN. There was one electrified center siding between the two mains at MP 7.7 Howelville that could hold around 65 cars but it was used infrequently. That coal train wreck, train Coal-4 Xtra, was caused by a broken wheel though they tried to nail the engineer for speeding. I knew him well, he was speeding but they could not prove it in those pre event recorder days.They were after him for a few years shooting him with radar and having special duty road foreman ride his trains.But he retired and that was it. We used to refer to that wreck as Willies coal pile as his name was Willard. He's been dead for thity years now so I guess they cant do anything to him now ! LOL