I was looking around on the CADL photo archive, when some photos caught my attention. I was looking around for civil defense pictures when I found these two photos:
1. (description from archive)
"Men looking at heavy equipment, at either the north or south side entrance to the Michigan capitol building." If i'm not mistaken, I think I might have just found another picture of Big Bertha. (it might be hard to see it since it's smaller)
2. (description from archive)
"Air raid sirens on power house, Michigan State College, East Lansing, Mich." These are what it looks like to be steam whistles. I actually didn't know this until now that East Lansing actually had these!
These were the only ones I could find. There might actually be more historic images of sirens in this area!