Yeah well, different places did it differently.
New York Penn Station, home to AMTK, LIRR, and NJT, but once upon a time it was PRR and LIRR was the stepchild of the PRR. Actually LIRR owned the franchise to build the East River Tunnels, and so PRR bought the LIRR to acquire that franchise which the LIRR could not afford to act on anyway.
So it was PRR’s station and PRR rand the show although LIRR used half of the station for its own operations. All interlocking towers were US&S pneumatics with PRR crews. They knew the LIRR schedules and when trains were coming and going, their own schedules were more fungible since moves to and from the Sunnyside yards could be more ad-lib as needed. All car-knockers were PRR personnel.
Then PRR seems to have run into hard times, they merged with NYCS to form the PC but prior to this they had already spun off the LIRR which was in its own financial doo doo. Penn Central went bankrupt, and the US government took it over calling the thing ConRail. ConRail still supplied commuter service to upstate New York and Connecticut. It was not a money making deal and eventually the MTA was formed and operated NYCT, LIRR and MNCR and in conjunction with CDOT, MNCR also ran some of the old New Haven routes.The State of New Jersey also assumed control of former PRR (PC, CR) commuter services. It is only recently that NJT also took over AMTKs Clocker Services.
Sometime during this time frame, I am not sure where, exactly, AMTRAK took over all long distance passenger service, but not the local, then still ConRail commuter service.
So the tenancy of NYP was fractured after the station was built. Even in the 1980s I recall that AMTK carknockers prepared LIRR trains for their trips, I assumed they did the same for NJT, Today with the construction of LIRR’s West Side Yards, LIRR crews took over the carknockers for LIRR. I assume NJT may have done likewise but of this I am not sure.
AMTK owns Penn Station lock, stock and barrel, and LIR