This 600 HP diesel switcher was part of an order of three SW-1's built by Electro-Motive Corporation (#912-914), November 10, 1939, as Boston & Maine 1109-1111. Along with 1111, these locomotives were used for many years as switchers at Boston’s North Station. Retired in 1959, all three were sold to Montpelier & Barre Railroad in Vermont, a Pinsly Company shortline railroad. The 1109 and 1110 became M&B 27 and 28, entering service in June 1961; 1111 was used for parts and scrapped in 1974. Transferred in 1982 to Pioneer Valley Railroad, a then-new Pinsly operation at Westfield, MA. The former 1109 was acquired October 1986 by RMNE. This unit is an unmodified example of 1939 diesel technology, complete with Allis-Chalmers electrical components and EMC-GM Series 567 Diesel engines that were the first of that type in New England railroad service. In 1992, the 1109 was cosmetically restored to its 1940 appearance as a B&M unit, the oldest existing diesel locomotive used by a New England railroad. In March 2008, B&M 1109 was carefully moved to the Naugatuck Railroad, and is currently on display at Thomaston Station.