PVC steam whistle

I saw on Ebay plans on how to make a 4 and 6 chime steam whistle out of PVC piping. The only thing is is that I don't feel like paying $20 for the plans. Does anyone here know how to make a 4 or 6 chime steam whistle that sounds just like a steam locomotive? I would greatly appreciate it.

Thanks,
Matt

Wont the Stea m melt the plastic pipe?

Yes it would, thats why you operate them on compressed air.