I found this photograph on the internet at my Link page Fallen Flags.Org, which is located to the right of your computer screen at www.rr-fallenflags.org. This is absolutely one of my favorite sites.
The former New York, New Haven & Hartford Railroad, was one of several North American railroads that was in a big hurry to retire steam locomotives A.S.A.P, and quickly replace them with modern efficient diesel electric locomotives. The New Haven had several diesel locomotives from Alco (American Locomotive Company), Fairbanks Morse & Company, General Electric, and eventually EMD on their roster by the late 1950's as well.
Railfan photographer Robert Jennings, photographed this New Haven Fairbanks Morse & Company H 10-44 min "Trainmaster" model roadswitcher diesel electric locomotive, passing through the city of Boston Massachusettes, way back in early September of 1958.
The locomotive is wearing the early New Haven diesel color scheme of orange and Dark Hunter green, wich I believe made it's debut during the late 1940's era on the NH.