NB Southern (New Brunswick Southern) was created out of part of Canadian Pacific’s (CP) divestiture of its lines east of Montreal in 1995. It operates over 131 miles/211 km of trackage from Saint John to McAdam (with a branch from McAdam to St. Stephen). It also operates over 105 miles/169 km of its subsidiary, the Eastern Maine Railroad, from McAdam to Brownville Junction, Maine. It interchanges traffic with CN in Saint John, with Pan Am Railways in Mattawamkeag, and with the MM&A in Brownville Junction.
In 2011 NB Southern took over operation of the former MM&A lines in Northern Maine. Their subsidiary is called the Maine Northern Railway. NBSR 9801 was relettered as MNR 9801 in mid-June.
In early 2002, NB Southern entered an agreement with CN that saw NB Southern lease CN’s Island Yard in Saint John. As part of that leasing, NB Southern acquired caboose CN 79635 to use in the local to serve the Irving Refinery and paper mill. NB Southern has also agreed to ship some of its long-haul traffic via CN. NBSR continues to ship through Brownville Junction and Mattawamkeag in Maine to points in New England and beyond.
NBSR initiated a trailer-on-flatcar (TOFC) train to Farnham, Quebec in late 2003, separate from its existing daily freight run. In 2005 the separate train was terminated and the TOFC traffic was run together with the general freight. As of early 2006 the TOFC traffic went to Maine on Tuesday, Thursday and Saturday mornings. This service was terminated in July 2006 and there is no more TOFC traffic on NB Southern.