Thu Sep 10, 2015 8:42 pm
According to the victory siren site.
In 1954, Chicago had 77 siren locations. 2 were vacant, 1 5hp Federal, 15 7.5hp Federals, 48 10hp Federals (STL 10), 5 40hp H.O.R, and 5 180hp Chryslers. 10 sirens were added in 1955, my guess is Thunderbolts.