From OpenStreetMap Wiki
(Redirected from Key:siren:purpose)
Jump to navigation Jump to search
Public-images-osm logo.svg emergency = siren
Bundesarchiv B 422 Bild-0010, Sirene.jpg
A loud noise maker, such as an air raid siren or a tornado siren. Edit or translate this description.
Group: Emergency
Used on these elements
may be used on nodesshould not be used on waysshould not be used on areasshould not be used on relations
Useful combination
Status: de facto

An outdoor warning siren (also known as a civil defense siren, air-raid siren, or tornado siren) is a loud noise maker used to deliver emergency alerts to the public, especially for fast-developing weather events such as tornados. Other common uses of sirens include summoning firefighters to a fire station or alerting the public about a tsunami, chemical spill, earthquake, or impending airborne attack.

There are two general types of outdoor warning sirens, based on the mechanism used to generate the warning tones. A pneumatic siren is powered by either a hand crank (mechanical) or an electric motor (electromechanical). An electronic siren uses electric circuitry to emulate the sounds of a pneumatic siren or to deliver voice messages, similar to a public address loudspeaker.

A siren may be mounted on a pole (similar to a power=pole) or on the roof of a building. A rotating siren produces sound in one direction at a time, relying on a motor to rotate a single horn in a circle, while an omnidirectional siren produces sound in every direction simultaneously through the use of multiple horns.

How to map

Map the siren as a node and tag it emergency=siren. If the siren is connected to an overhead power line, connect the siren to a power=line way.

Depending on the region, outdoor warning sirens are typically found near parks, schools, fire stations, factories, power plants, substations, or water towers. In aerial imagery, pole-mounted sirens are easy to confuse with power transformers (power=transformer) at all but the highest zoom levels, so confirm the siren in street-level imagery if possible.

Additional tags


OSM Emergency Map renders sirens with siren icons at zoom level 11 and above (example).

External links