eddiebear gave a superb short history of the PTCO. It was abolished by Guilford. ALL TRACKS in the Greater Portland area(Westbrook,Portland & S.Portland were considered "PT tracks". Get a pre Guilford MEC/Portland Terminal Timetable from say,the 1950s,and you will see where the" PT Limits",began and ended. PT switcher crews switched Rigby 'round the clock and all the customers in the limits.They also had track crews to maintain the ROW in the limits. Yes,the "Bishop Street track",which is the LAST active vestige of the Old W.N.&P in Maine, is referred to as the "B&M side" of the tracks @ Deering Jct. The east side of the D.J. yard is called the "Maine Central side". 3 customers on the W.N.&P.,busiest & farthest away from Deering Jct.is a Georgia-Pacific Dist. Ctr.very near the Maine Turnpike,which cut the line when it was extended in 1954-55. While some W.N.&P. tracks remain at the SAPPI mill(again,called the B&M side),sad to say that the paper mill rarely uses rail,even chemicals,that came into the "Maine Central side",or Wood Yard,off Bridge St. are mostly trucked in. Yet,SAPPIs other mill,in Hinkley,is a huge user of rail,requiring a couple of daily locals outta Waterville! Bud