The Pennsylvania Railroad locomotives were later refitted with the Pennsy's trademark Belpaire fireboxes. None of the originals built under USRA auspices or any of the subsequent copies were preserved.[3]
^Drury, George (19 November 2015). Guide to North American steam locomotives (2nd Revised ed.). Waukesha, Wisconsin: Kalmbach Publishing Company. pp. 51–52. ISBN978-1627002592.
^Drury, George (19 November 2015). Guide to North American steam locomotives (2nd Revised ed.). Waukesha, Wisconsin: Kalmbach Publishing Company. pp. 101, 106. ISBN978-1627002592.
^Drury, George (19 November 2015). Guide to North American steam locomotives (2nd Revised ed.). Waukesha, Wisconsin: Kalmbach Publishing Company. pp. 174, 180. ISBN978-1627002592.
^Drury, George (19 November 2015). Guide to North American steam locomotives (2nd Revised ed.). Waukesha, Wisconsin: Kalmbach Publishing Company. pp. 136, 138. ISBN978-1627002592.