In this period LIRR freights came up the hill from Cold Spring Harbor either doubled by single ex-Pennsy H-9 or H-10, or in charge of two of same. After FM C-liner diesel locos had cut down the big Gs and Pacifics on the commuter runs the H class steam handled the freights into 52, I believe, or later. 

Saturday was big day , presumably because there was less passenger stuff. In 1950, on Saturday, I stood by Koski's farm and watched two consolidations bring 120+ cars into Huntington Station going east. They proceeded to distribute cuts of cars on southernmost track so they did not block the many street crossings. All the time they had crew flagging these crossings. They (or someone working for them) then turned off the warning mechanism(s) so that these cuts could remain there without all the crossing signals flashing and ringing. 

They took one loco with about 30-40 cars and the caboose and went east after letting the westbound passenger through. The other loco, which had plenty of groundpounders left to make up switch crew ,proceeded to work the freight cars in and out of several building supply companies, two concrete plants, fuel dealers and the team tracks there on Railroad Avenue. All the while they moved out of the way of the various passenger trains had to get through. 

At some point they left and apparently headed down the freight tracks into the harbor, and came back worked the industrial track that went towards Melville that had a large concrete block maker, who also had a sand pit which 
loaded out gondolas. I know that these guys worked all the many spurs that went to the big institutions (VA Hospital, State Mental Hospitals- LI had corner on nut houses) into the clay and sand pits, down to the Sound at all the old port towns( not just Port Jefferson) and served the booming construction industry.

Not having a car I couldn't follow the guys around , but did run into them at other points. The first insulated box car (labeled as such) I ever was aware of, was being loaded with sod coming from sod farms to the south on the Huntington Station team tracks.

I know enough today, to tell you that the existing pay scales made this a highly profitable way to make a living, and accounted for the old guys in their 60s and 70s, with whiskers, that ran these trains. The day ended at Huntington Station around 6 P.M.-7 P.M. when they pulled the scrap yard and tacked on the caboose and went west with everything collected from east of there. 

My guess is that they had worked the western towns on the way out , and only were running for home when they went over the Nassau County line on their way back. It was an enormously different world, on Long Island - railroadwise and otherwise, from what exists today where only the commuter ops are meaningful.