The branch line for the NJ Transit starts from Philadelphia 30th Street Station and terminates at Atlantic City Rail Terminal which is a few blocks away from the boardwalk. This line takes about an hour and 30 minutes to complete and is non electrical. Rolling stock is GP40PH-2B which is used for motive power and coaches are comet. AI layers would be Keystone Service trains, NE Regional trains, and various long distance trains. All run by Amtrak.
Excellent idea in fact it can layer onto Northeast Corridor Trenton to Boston route the NYC section as a NJCL Hoboken service from Rahway. By the way this route of yours shares the same diesel stock as my suggestion the Raritan Valley line. They were to run double-deckers here they were just open the entire train unlike Raritan Valley Line which has the last two stops I-78 exits 16-18 Annandale and High Bridge confined to the last two cars when running double deckers