Class T (Locobase 817)

Data from table in June 1907 American Engineer and Railroad Journal and from "'Prairie' Type Locomotive, Northern Pacific Ry," The Locomotive Magazine, Vol XII (15 December 1906), pp. 212-213.

Procured for light freight service in a wheel arrangement that was a first for the NP. They were among 70 engines procured by the NP that year with combustion chambers.

10 were later converted to light Mikados as the W-4s. 18 more were modified as T-1s; see Locobase 918.

Class T-1 (Locobase 818)

Modified from Ts in the 1920s.

NB: The direct heating surface (including the firebox heating surface) is an estimate calculated by subtracting the calculated tube heating surface from the reported total evaporative heating surface.