by EAST
ok im new here and new to trains in general, but today i was watching a freight train (in athol, MA) go by, and it was fairly long going about 25 mph. but then at the end i noticed a light, and there was a engin at the back of the train it was definitely turned on lights and everything (in fact there was sparks flying out of the exhaust). any idea why they were doing this? never seen it before and im real curious