In 1955, Fairbanks Morse offered a new design for their existing H16-44 Phase I/II model locomotives. These changes involved raising the walkway & simplifying the short & long hood to make construction easier.  Exterior-wise the locomotives looked much like their bigger brother – the H24-66 but with 4 axles instead of 6.  Under the hood the locomotives were nearly identical to the earlier phases of H16-44 except for replacing the Westinghouse Electrical System with a more reliable General Electric system. 

A total of 165 of the H16-44 Phase III Locomotives were built between 1955 and 1963. Locomotives for the Canadian Pacific Railway & Canadian National Railway were built by Fairbanks Morse subsidiary Canadian Locomotive Company. A total of 58 H16-44s of were built at this plant. The last H16-44 was built for the Ferrorcarril de Chihuahua al Pacifico Railroad in 1963.  This was the last Fairbanks Morse Locomotive to roll off the assembly line as the company folded the same year.