Maine Central class O 4-6-0

The Maine Central class O was a group of 4-6-0 steam locomotives numbered 351 to 390, bought from 1903 to replace the older class P 2-6-0 engines and first meant for heavy freight. The Schenectady plant of the American Locomotive Company built the first of them, Baldwin supplied numbers 373 to 382 with Walschaerts valve gear, and the Lima Locomotive Works built the last eight, numbers 383 to 390, in 1923 as sub-class O-4, with Baker valve gear and a longer tender holding fifteen tons of coal. Displaced from the heaviest freight work by class W 2-8-0s after 1910, the class kept working branch line trains until diesels replaced it after World War II.