1906 products of the American Locomotive Company's Schenectady plant, the eight Atlantic type (4-4-2) locomotives of the New York Central & Hudson River's class Ih were reclassified to I-10h when they were equipped with superheaters, between 1912 and 1917. Very likely the superheating occurred while the West Albany Shops was retrofitting them with the Baker valve gear, as shown in this illustration from a catalog issued around 1915 by the Pilliod Company of Swanton, Ohio, manufacturers of the Baker gear. During this time, in 1913, they were renumbered by dropping the initial "3" from their original number, so that No. 3823 became NYC No. 823. These engines had 79-inch drivers and cylinder dimensions of 21x26 inches, and their boiler pressure was 185 pounds. They weighed 195,000 pounds without tender after being superheated, and exerted 24,500 pounds of tractive force. The photo reveals that, in the original configuration of the Baker gear, the combination lever was connecter to the crosshead from the rear; in later applications the combination lever is usually between the cylinder and the crosshead. No. 823 was the first of the group to be retired, in 1926, but one member of the class lasted till 1934.