The first two scenes on this video are 4500's original whistle, being blown by Mike Massy, 4500's restoration manager, several years ago. This was at the Pawnee, OK steam tractor show. The wood fired power house boiler was putting out about 80 psi at the time, but you can get an idea what it should sound like at 250+. I don't know where this whistle is now, maybe back on the engine again, but if not, hopefully in a safe place. A few years ago, I took a six chime Santa Fe whistle down there and Matt Ritchie (second scene) climbed up to the top, mounted it, and we blew it off & on all afternoon. I don't know if they do that at Pawnee anymore since Matt passed on or not. I do have a couple of whistles I'd like to hook up somewhere, will have to watch for a whistle blow event somewhere this spring or summer.