# Severnside Sirens

The Severnside Sirens are a system of Civil defense sirens located along the South Severn Estuary coastline from Redcliffe Bay to Pilning, northwest of Bristol. They are activated by Avon and Somerset Police in the event of a potential incident at one of the COMAH sites located in the area, mainly in and near Avonmouth. The system was setup in 1997 following a fire at the Albright and Wilson 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, Bristol City Council, and South Gloucestershire Council, 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. Most of them are Federal Signal Modulators. They are operated via radio signal from a control system at Avon and Somerset Police Headquarters in Portishead.
Severnside Sirens, as of Jan 2022 :
| Designation | Location | Coordinates | Comment |
| Siren 1 "Bristol Water" | Shirehampton - in Lamplighters Marsh. | 51°29′04″N 2°41′03″W﻿ / ﻿51.484522°N 2.684222°W﻿ / 51.484522; -2.684222 | This siren is directional, with loudspeaker cones pointed across the river to Pill and towards Shirehampton proper. |
| Siren 2 "Ridingleaze Clinic" | Lawrence Weston - behind the Bristol City Children and Young People's Services building | 51°30′03″N 2°39′32″W﻿ / ﻿51.500824°N 2.658872°W﻿ / 51.500824; -2.658872 | |
| Siren 3 "Portishead Fire Station" | Portishead Fire Station car park | 51°29′11″N 2°46′06″W﻿ / ﻿51.486291°N 2.768267°W﻿ / 51.486291; -2.768267 | |
| Siren 4 "Bristol Port Company - Police Station" | Royal Portbury Dock next to the Port of Bristol Police Station | 51°29′23″N 2°43′12″W﻿ / ﻿51.489605°N 2.720074°W﻿ / 51.489605; -2.720074 | |
| Siren 5 "Bristol Port Company - West Town Gate" | Avonmouth, at the end of Victoria Road | 51°29′44″N 2°41′39″W﻿ / ﻿51.495548°N 2.694250°W﻿ / 51.495548; -2.694250 | |
| Siren 6 "Bristol Port Company - X Berth" | Royal Edward Dock - opposite St Andrews Road railway station | 51°30′45″N 2°41′52″W﻿ / ﻿51.512590°N 2.697728°W﻿ / 51.512590; -2.697728 | |
| Siren 7 "Former Sevalco Site, Chittening Road" | Chittening, towards the north end of Chittening Road | 51°31′55″N 2°40′24″W﻿ / ﻿51.531813°N 2.673405°W﻿ / 51.531813; -2.673405 | Located across the road from the site of the former Sevalco carbon black factory. |
| Siren 8 Govier Way (Royal Mail SWDC) | Outside Royal Mail South West Distribution Centre on Govier Way | 51°33′04″N 2°39′05″W﻿ / ﻿51.551094°N 2.651395°W﻿ / 51.551094; -2.651395 | |
| Siren 9 "BT Exchange, Pilning" | Pilning - by the telephone exchange building behind the Pilning Surgery | 51°33′51″N 2°38′29″W﻿ / ﻿51.564183°N 2.641430°W﻿ / 51.564183; -2.641430 | |
| Siren 10 "Hallen" | Hallen, In the vicinity of the Hallen Fuel Depot between the village and Henbury | 51°30′52″N 2°38′08″W﻿ / ﻿51.514390°N 2.635454°W﻿ / 51.514390; -2.635454 | Added to the system in 2013. |
| Siren 11 "Redcliffe Bay" | Redcliffe Bay, on the Arqiva transmitting mast | 51°28′20″N 2°48′31″W﻿ / ﻿51.472287°N 2.808737°W﻿ / 51.472287; -2.808737 | This siren is directional. Added to the system in 2006 as a klaxon, replaced with a Federal Signal in 2019. |
| Siren 12 "Redcliffe Bay" | Redcliffe Bay | 51°28′30″N 2°48′44″W﻿ / ﻿51.474966°N 2.812173°W﻿ / 51.474966; -2.812173 | This siren is directional. Added to the system in 2006. Made by Klaxon, running on Federal Signal controller. |

## 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.
| Videos of the sirens being tested | Video Links: |
| Siren 1 - Shirehampton, Lamplighters Marsh | https://www.youtube.com/watch?v=JBIeYh30hCU |
| Siren 2 - Ridingleaze Clinic | https://www.youtube.com/watch?v=PirqOqzbkOc&t=2s |
| Siren 3 - Portishead Fire Station | https://www.youtube.com/watch?v=Kcuv84Fwues |
| Siren 4 - Bristol Port Company | No Videos |
| Siren 5 - BPC, West End Gate | https://www.youtube.com/watch?v=l84HapE7y4Y&t=52s |
| Siren 6 - BPC, X Berth | https://www.youtube.com/watch?v=FgjRq5PCRyE&t=120s |
| Siren 7 - Chittening Road | https://www.youtube.com/watch?v=OGUuKEXp_RE&t=31s |
| Siren 8 - Govier Way, Royal Mail SWDC | No Videos |
| Siren 9 - Pilning, BT Exchange | https://www.youtube.com/watch?v=zKxW8NYR9Dw&t=17s |
| Siren 10 - Hallen | No Videos |
| Siren 11 - Redcliffe Bay, Arqiva Mast | https://www.youtube.com/watch?v=4SHCkm6n-rg&t=60s |
| Siren 12 - Redcliffe Bay | https://www.youtube.com/watch?v=q3Yi7GE7yes |