Emergency vehicle equipment is used in the United Kingdom to indicate urgent journeys by an emergency service. This usage is colloquially known as "blues and twos", which refers to the blue lights and
An Incident Response Unit operated by Norfolk Fire and Rescue Service with a blue lightbar on top, alternately flashing LED lights on the front, and flashing headlights. This vehicle is part of the New Dimension programme and consequently does not carry any insignia of Norfolk Fire and Rescue Service.
Six Metropolitan Police Service motorcycles driving with the blues and twos on. They can be seen breaking a number of normal traffic rules. Each motorbike has driven through a red light, and the motorbike on the far right can be seen driving on the wrong side of the road and passing on the right of a keep left sign.
Siren (alarm)
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A siren is a noise-making warning device. There are two general types: mechanical sirens and electronic sirens. Civil defense sirens are mounted in fixed locations and used to warn of natural disaster
Emergency vehicle equipment in the United Kingdom
…indicate urgent journeys by an emergency service. This usage is colloquially known as "blues and twos", which refers to the blue lights and the two-tone siren once commonplace (although most sirens now have a range of tones like Wail, Yelp, Phaser, and Hi-Lo). A call-out requiring the use of lights and sirens…
A Telegrafia Pavian.
A Whelen WPS-2805 electronic siren imported to Saudi Arabia by HSS Engineering for use as a civil defense siren.
There are 8,200 alarm sirens for civil protection throughout Switzerland. They are tested once a year, on the first Wednesday of February. Sound sampleⓘ
The air raid siren used to alert the town of Lowestoft during World War II.