So for some reason locomotive whistles don't work in FTB. This is odd, because the whistle sound files ARE in RC's jar file, and it's the same version of RC I used to run on my Voltz server, where the whistles worked fine. Apparently I'm not the only one with this issue.
Edit: Culling out every mod but Railcraft brings the whistles back, but I'm really not up to trying to figure out the exact culprit.
Edit: Culling out every mod but Railcraft brings the whistles back, but I'm really not up to trying to figure out the exact culprit.