Fire engine siren

TThe tone sequence siren (German: Martinshorn) is a component of the fire engine/water tanker Magirus F Mercur 125, built in 1961. The vehicle was originally in use in the factory fire department of the Bochumer Verein. Today the vehicle is an exhibit of the Fire Department Museum in Hattingen.
In combination with the flashing blue lights it represents the police’s right of way and tells the other traffic participants to clear the road instantly.
This siren produces its tone sequence with a compressor system. Compressed air is directed alternately by a valve system through two siren horns which are differently tuned to generate a beat frequency.
In order to distinguish themselves from signals of other vehicles such as the tram, the fire department and the police have used sirens since the 1930s to signal their right of way. Sirens were manufactured solely by the company Deutsche Signal-Instrumenten-Fabrik Max B. Martin, which is why they are named Martinshorn in German.



Sound recordist: Konrad Gutkowski / Jonathan Nicolai
Photographer: Konrad Gutkowski / Jonathan Nicolai
Video recordist: Konrad Gutkowski / Jonathan Nicolai