The Severnside Sirens are a system of

Civil defense sirens A civil defense siren, also known as an air-raid siren or tornado siren, is a siren used to provide an emergency population warning to the general population of approaching danger. It is sometimes sounded again to indicate the danger has pas ...

located along the South

Severn Estuary The Severn Estuary ( cy, Aber Hafren) is the estuary of the River Severn, flowing into the Bristol Channel between South West England and South Wales. Its high tidal range, approximately , means that it has been at the centre of discussions in t ...

coastline from Redcliffe Bay to

Pilning Pilning is a village in South Gloucestershire, England, close to Redwick and Severn Beach. Pilning is close to the M4, M49 and A403 roads, and has the South Wales Main Line railway running through it, with a minor station. The civil parish ...

, northwest of

Bristol Bristol () is a city, ceremonial county and unitary authority in England. Situated on the River Avon, it is bordered by the ceremonial counties of Gloucestershire to the north and Somerset to the south. Bristol is the most populous city in ...

. They are activated by

Avon and Somerset Police Avon and Somerset Police is the territorial police force responsible for law enforcement in the county of Somerset and in four districts that used to be in the defunct county of Avon: Bristol, Bath and North East Somerset, North Somerset and So ...

in the event of a potential incident at one of the COMAH sites located in the area, mainly in and near

Avonmouth Avonmouth is a port and outer suburb of Bristol, England, facing two rivers: the reinforced north bank of the final stage of the Avon which rises at sources in Wiltshire, Gloucestershire and Somerset; and the eastern shore of the Severn Estuar ...

. The system was setup in 1997 following a fire at the

Albright and Wilson Albright and Wilson was founded in 1856 as a United Kingdom manufacturer of potassium chlorate and white phosphorus for the match industry. For much of its first 100 years of existence, phosphorus-derived chemicals formed the majority of its prod ...

site in 1996.

Severnside Sirens Trust

Severnside Sirens Trust Limited is the organisation responsible for maintaining the system. It is a registered company (number 3348008) and charity (number 1063224) and was incorporated on 9 April 1997. The trust's activities are funded by the 3 local authorities whose constituents the sirens serve,

North Somerset Council North Somerset Council is the local authority of North Somerset, England. It is a unitary authority, having the powers of a non-metropolitan county and district council combined. It provides a full range of local government services including Cou ...

Bristol City Council Bristol City Council is the local authority of Bristol, England. The council is a unitary authority, and is unusual in the United Kingdom in that its executive function is controlled by a directly elected mayor of Bristol. Bristol has 34 wards ...

, and

South Gloucestershire Council South Gloucestershire Council is the local authority of South Gloucestershire, England, covering an area to the north of the city of Bristol. As a unitary authority it has the powers of a non-metropolitan county and district council combined. I ...

, and from donations from the organisations running the COMAH sites themselves.

Sirens

The sirens themselves are mounted on dedicated poles and all but one are manufactured by the

Federal Signal Corporation Federal Signal Corporation is an American manufacturer headquartered in Oak Brook, Illinois. Federal Signal manufactures street sweeper vehicles, public address systems, emergency vehicle equipment, and emergency vehicle lighting. The comp ...

. Most of them are Federal Signal Modulators. They are operated via radio signal from a control system at

Headquarters in Portishead.

Testing

The sirens are tested at 1500 on the 3rd of every month. The test comprises the following: * 3 minutes of the alert warning (a continuous, stepped, rising tone) * 1 minute of silence * 1 minute of the all clear siren (a continuous constant tone) Local volunteers monitor the sirens on test day.

References

{{reflist

External links

Severnside Sirens Trust
- the charitable organisation responsible for running the system Warning systems Sirens Emergency population warning systems