Built by Baldwin predecessor Burnham, Williams & Company in 1907, the Frisco's 4-6-0s of class 1400 were not originally superheated but were modified in 1929 with 508 square feet of superheating surface and 2410 square feet of evaporative heating surface. Their grate area of nearly 48 square feet was made possible by the wide spacing between the second and third driving axles. Their engine weight was 196,000 pounds and they put out 33,887 pounds of tractive effort. Cylinder specifications were 23x26 inches, and boiler pressure was 200 p.s.i. Some members of the class remained in service till 1951, near the end of steam operation on the Frisco. An unidentified lensman photographed No. 1406 at St. Louis on July 20, 1939; the image comes to our Random Steam Collection courtesy of Donna Harrison-Rodeghiero.