In the mid-2000s the MBTA issued a request for proposal for new diesel locomotives to replace its aging fleet, much of which dated to the late 1970s. MBTA turned to MotivePower, and ordered 20 new HSP46 locomotives on July 14, 2010, at a cost of $114.6 million. On July 27, 2011, the MBTA released images of a new
paint scheme for the authority's HSP46 fleet. It was chosen by the general public in an online survey. On April 10, 2013, the Board approved the purchase of the remaining 13 option locomotives, bringing the current order total to 40 units (2000–2039), at a total cost of $240 million. On October 24, 2013, the first pilot unit, No. 2001, was delivered to the
MBTA Commuter Rail Maintenance Facility to begin testing and training. Two other pilot units were also released from MotivePower: No. 2000 to GE's Test Facility in
Erie, Pennsylvania, and No. 2003 to the
Transportation Technology Center test facility in
Pueblo, Colorado. Only No. 2001 was given the MBTA paint scheme; the other two test units were unpainted. On April 16, 2014, No. 2001 entered revenue service, with its first round trip taking place on the
Haverhill Line. , 36 of the 40 locomotives are in service. En route to the MBTA, the locomotives were sent to the
Providence & Worcester Railroad, which is subcontracted to MPI to prepare the units for revenue service. While the repairs were performed under warranty at no cost to the MBTA, they constituted an additional delay that prevented some of the units from entering service before the end of 2015. The multiple delays and early mechanical issues have raised concern from industry commentators about the MBTA's procurement process and the overall quality of the locomotives. Fleet availability fell to 27 of 40 in early April 2017. In December 2025, the MBTA issued a $223 million contract with Wabtec to overhaul the 40 locomotives. They are expected to be completed from February 2029 to March 2032. ==References==