WWII - Passive Air Defense 1943

The image from the Nazi Propaganda shows a siren vehicle that warns the civilians during an air raid warning in July 1943. Place unknown. The Nazi Propaganda! on the back of the image is dated 1 July 1943: "It may occur that the siren cannot be used due do desctructions. In such cases, the parts of the city which are concerned receive air raid warnings and "all clear" signals via a mobile siren. Mounted on a motor vehicle, the sirens give the same alarm signals as the fixed sirens. The signal, however, lasts a little longer because the mobile siren has to drive slowly and the assigned route can usually not be completed within one minute. If there are no mobile sirens available, in some cases other improvised devices can be employed when mounted on a motor vehicle or bicycle. Our image shows one such improvised alarm device (a siren operated by hand). "