Paul - I agree that this Chicago livery is indeed probably the most elegant of any fire department anywhere! Of course, it has been widely copied all over the US, and it is especially popular in jurisdictions around the Chicago suburbs.
It began with the earliest enclosed apparatus and was rivalled at the time only by the Paris' Regiment des Sapeurs-Pompiers, who unfortunately dropped the black roof treatment many years ago.
Black fabric roof coverings were used on many enclosed coachbuilt British fire trucks in the 1930s, and were standard on early postwar Dennis appliances in the 1940s and 50s, as well as a few other brands. But UK and other European fire service never really embraced black painted roofs.
The black roofs originated with a fleet of enclosed chief's cars bought by CFD, which had wood framed bodies with fabric covered roofs which were black.
Subsequent purchases of enclosed fire trucks followed the same color scheme, starting with fabric then painted meal.
Living in Chicago now, it is no surprise that CFD was one pf the earliest fire departments to buy enclosed cars. Last month it got down to - 34 centigrade here!
Added by Paul Warnock on 03 May 2013.