Baltimore and Ohio class S
Baltimore and Ohio Class S comprised two classes of 2-10-2 locomotives.
The S class proper were 31 locomotives built in 1914 by Baldwin Locomotive Works and numbered 6000–6030. The S-1 class comprised 125 locomotives numbered 6100–6224. They were built between 1923 and 1926, 75 by Baldwin and 50 by Lima Locomotive Works.
They were nicknamed "big sixes" because of their size and because, until renumbering in 1954, their road numbers all began with "6".
