Pneumatic Locomotives 

Developed in the 1870's for use in areas where smoke and fire were operational hazards, pneumatic locomotives found their way into numerous industrial settings.  By 1900 they were a common sight in the mining industry.  Although major locomotive manufactures including Vulcan, Baldwin, Dickson, and later American Locomotive Co. built pneumatic locomotives, the production of the H. K. Porter Co. far exceeded the all the rest.  Much of H. K. Porter's success can be attributed to their purchase of the patent rights to Charles Hodges compound compressed air engine.  Later manufactures included Eimco and Universal Air Tramaire.  With the refinement of battery and electric power, the use of compressed air locomotives has fallen out of favor and air locomotives have largely disappeared from active use.

Links to Material:

Porter

Vulcan  Baldwin Eimco UAT Photos Patents Online Books