Economic restructuring in the early 1920s included purchasing a few modern steam locomotives in 1923 and 1924 while eliminating subsidiary branch lines serving Bridgton, Belfast and Franklin County.
J. G. Brill Company 68 horsepower (51 kW) Model 55 gasoline-powered baggage-mail motor car number 700 was purchased in 1922 and scrapped in 1930.
[4] Maine Central's first wholly owned diesel-electric locomotive was an Ingersoll Rand 600 horsepower (450 kW) railcar built as demonstrator OE-600 in 1933.
It then spent two years pulling Rumford Branch passenger trains before conversion to unpowered maintenance of way tool car number 950.
Road engines built through the period of joint operation shared the B&M paint scheme of maroon with gold stripes first applied to B&M EMD FTs.
Similar yellow paint schemes were applied to all subsequent road switcher purchases until Guilford control.
Maine Central also purchased seven GE 44-ton switchers between 1941 and 1947 for use in Augusta, Brunswick, Livermore Falls, Vanceboro, Eastport, and the unconnected upper and lower yards at Lewiston.
The Brunswick assignment proved too heavy for a 44-ton switcher; but they eliminated need for firemen and 0-6-0 maintenance crews in the remaining locations.
[10] Class DS-4d were similar but equipped for multiple-unit (MU) operation to pull branch line freight trains.
Portland Terminal Company had been using the GP7 as a mileage equalizer pulling commuter trains out of North Station until replaced by Budd Rail Diesel Cars.
[22] Steam generators were removed from most of the EMD GP7s as their assignments became increasingly focused on freight trains west of Bangor.
Through the 1960s these four GP7s pulled extra trains of New Haven Railroad coaches carrying children to summer camps in Maine.
The U18Bs were individually named after Maine personalities and places of the American Revolutionary War in recognition of the United States Bicentennial.
[26][27] After the bicentennial, Maine Central began purchasing used locomotives including fourteen GE U25Bs from the liquidated Rock Island Railroad.