Devon, then again, if the engine shed is a shop, and the locomotive only goes in there for repairs, then who gives a rip if the tender sticks out of the doors while the locomotive is being worked on?
As for steam locomotives burning oil, I rode behind a 10 wheeler in Texas that burned waste motor oil. Now there was a interesting smell. (http://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-yell.gif)The oil tank was built to slide into (set into) the coal hopper of the tender. So, while she burned oil, she could still be converted back to burning coal like a proper old gal should.
The steam locomotives at Bush Gardens burn propane, and I thought the ones at Disney did too. Again, its a smell that is wrong for a steam locomotive, but liquid (and gas) fuels are cleaner then coal or wood.