The ten class I-5 Consolidations were delivered by ALCO-Brooks in 1903. For burning anthracite culm they were given a Wootten firebox with an 82 square foot grate and Camelback design. In the 1920s, all were superheated, with one locomotive keeping the cylinder diameter of 20 inches and the remaining getting 21 inch diameter cylinders. The former were designated I-5s while the rest became I-6s. The tender capacity was increased by a ton by installing boards. The last four members of the class remained in service until 1947. 