Acadia Coal Company No. 42 is a 2-6-0 'Mogul' steam locomotive built by the Schenectady Locomotive Works (later part of Alco) in 1899 under works number 5103.
Originally it was built as a 2-6-4T tank engine for Dominion Coal as their No. 16. In 1902, it was sold to Sydney & Louisburg who had renumbered it as their No. 42. It was later rebuilt around 1947 into a 2-6-0 locomotive and was given a tender. No. 42 was then sold to the Acadia Coal Company in 1955 where it was used to switch and handle coal hoppers at their mine operations.
Following the dieselization of Acadia Coal Company, No. 42 was purchased by a private owner in 1963. The owner featured the locomotive in a commercial to promote a local paint company that they also owned.
From 1973 to 1979 it was leased to the Cape Breton Steam Railway, which operated over part of the old Sydney & Louisburg line. It also ran on the Salem & Hillsborough Railroad for 5 years.
After operating on tourist railroads for several years, No. 42 was eventually donated to the Museum of Industry, in Stellarton, Nova Scotia, Canada in 1983 and has resided there ever since.