Transit police has been patched on the COMIRS and the MSP trunk for a while.
KB1KVD, Dose Fall River have a yard channel? 161.4750 is loud & clear! Who are we hearing most of the time? Is it the dispatcher or the train.
Fall River and New Bedford layovers are on AAR 051 (160.875 MHz) just like every other layover with the exception of Readville which is on AAR 007 (160.215 MHz) and Southampton Street which is on AAR 063 (161.055 MHz). The yard channel is really only going to be active during the overnight hours when the trains are coming into the layovers and mechanical forces are getting equipment ready. Once the equipment is tied down for the night the mechanics may operate on the mechanical channels AAR 047 (160.815 MHz) but most times they're radio silent at the outlaying points. The only yards that are really active 24/7 are Boston Engine Terminal on AAR 051, Readville on AAR 007 and Southampton St on AAR 063.
Since you are listening on AAR 091 (161.475 MHz) that would be the South Coast Dispatcher, train crews, signal maintainers, and track patrols. More than likely you are going to hear the dispatcher since they have 5 base site on the territory which cover from Middleboro to Fall River and New Bedford. Generally you are not going to hear conductors since they're inside the train on a handheld unless your next to the train. You will hear the loco's from about 3-4 miles away but that's about it. Engineering Dept employees are usually using handhelds as well so hearing them far away is also rather limited unless they're hi-railing then they're using the mobile with a high gain antenna.