compressed air train engine for mining.... and used as a piggy bank in a Lions Club fundraiser

 https://exporail.org/canrail/canadian_rail_1990_plus/canadian-rail-423-1991.pdf  is a 1991 newsletter of Canadian rail, in PDF form, if you want to look through back issues. 

https://www.maritime-executive.com/editorials/compressed-air-over-water-for-short-distance-propulsion