Daz211, sorry to take issue, but the problem at STN doesn't seem to be mainly the belts. In my case recently, the only reason the baggage hall was so full, was all the people were standing arround waiting for a carousel to be allocated to their flight.
At no time were more than three out of five carousels in action. The reason why I mentioned the forlorn bags still on the carousel, clearly mis-delivered, was that nobody had bothered to remove them (for the entire 1.5 hours I was there waiting for my bags). Next time any of you go through STN, I recommend to check the destination tags of these bags, just for a laugh to see the destinations!
Further to that, there was a very fine drizzle on the evening in question. When my bags did finally arrive, they were significantly wet, which means that for a good portion of that time, they were sitting out in the open (unless of course, this undercroft you mention isnt "under" at all).