The OR&L (Oahu Railway) had its fueling facility near the Honolulu roundhouse. Oil storage was in a very large tank built in to the Ewa (west) end of the second story of the roundhouse. Oil lines to serve the three or four track fueling area were overhead along with equipment to fill sand domes as well. There are several recent books on Hawaiian railroads which have good pictures of this facility. The OR&L converted to oil from coal in the early 1900s. Most, if not all, other railroads in the islands were oil fired, although some of the sugar plantation lines may have burned bagasse in their locomotives. -- Ed