Securiton Aspirating Smoke Detection for Prison Protection

September 2017


A Securiton aspirating smoke detection (ASD) system from Patol is protecting the inmates and staff at one of the UK’s largest prisons following an installation at HMP Northumberland.

The category C prison, with its capacity for 1,348 male offenders, is Britain’s seventh largest jail and is located in Acklington, 15 miles north of Newcastle. As with any prison, the safety of inmates is a prime consideration and when Sodexo Justice Services - the private sector operator responsible for HMP Northumberland - decided to review the prison’s fire safety measures, they approached the Static Systems Group. Static Systems has extensive experience in working with the Ministry of Justice and HMPPS (Her Majesty’s Prison and Probation Service) to provide communications and alarm systems to the Prison Service. Having evaluated the specific requirements of HMP Northumberland, Static recommended and installed the Securiton SecuriRAS ASD system, available in the UK from sole distributor Patol.

ASD is widely used in custodial applications given that they present a number of challenges in terms of fire safety, including an increased fire risk from factors such as the potential for prisoners to smoke cigarettes in their cells or other parts of the facility, intentional lighting of clothing, bedding or rubbish by unruly inmates or faults with electronic equipment. Vandalism of/tampering with conventional point detectors can also be an issue, with ASD providing the opportunity to site the pipework out of reach of prison inmates but still allowing access to the detectors for ease of maintenance by authorised personnel.

Precision and reliability are key focuses in the SecuriRAS technology – again both important factors in a custodial environment where keeping false alarms to a minimum is a prime consideration. Some eight detectors and the associated pipework were employed at HMP Northumberland, a mix of ASD 531 and ASD 532 detectors. The ASD 531 is a one-channel detector for monitoring smaller premises, offering quick commissioning through configuration directly from the device rather than requiring a PC. The ASD 532 is also a one-channel detector featuring a smoke-level indicator which offers a compact solution for small to medium-sized applications. Up to five alarm levels can be programmed within the detector sensitivity range of 0.002%/m to 10%/m and this, combined with the use of two detectors from the EN54-20 Class A, B & C approved range, enabled Static Systems to tailor the detection to the different environments within the facility, including the laundry and the gym.


The laundry presented a particularly challenging environment, with its humidity and the chemicals used meaning that corrosion of the connections could prove an issue with point detectors. The SecuriRAS detectors were particularly suited to the humid environment with the pipework through which the air is drawn entering the detector from the bottom. This means that any condensation collects in the bottom of the pipe rather than entering the detector. Patol offers the option of fitting a water trap to allow any condensation to be viewed through a transparent sight glass. A patented lint filter also suppresses even the finest dust particles that would otherwise falsify the detection process. A further factor in the laundry was its rooflights, which, at over 800mm deep, required gooseneck pipework to ensure the area was fully protected.

ASD provides early detection of fire which is a significant benefit in buildings where large numbers of people need to be evacuated – in a prison this allows a safe and orderly evacuation of an offender population which, in the case of HMP Northumberland, could be more than 1,300. Eradicating false alarms is also an issue as evacuations need to be confined to actual emergencies. High reliability is a characteristic of the SecuriRAS range, with all of its detectors employing the same tried and tested HD detector with its large volume smoke chamber providing outstanding sensitivity combined with an impressive long service life. The detectors at HMP Northumberland feature a pre-alarm stage, to enable a potential fire incident to be investigated before instigating a full-scale evacuation.

Created from the amalgamation of what were originally two separate prisons, HMP Northumberland took on its new name in 2011, with Sodexo Justice Services appointed on a 15-year management contract on 1 December 2013.