The Guildhall is situated in the centre of Portsmouth and dominates Guildhall Square. Following extensive damage caused by bombing during World War II, the building was rebuilt during the 1950s. Today it is used as an entertainment and conference centre, as well as housing The Coroner’s Office, the Council Chamber and Mayoral Suite.
There were a number of issues to take into account when designing the new fire system. In some areas, such as the Mayoral Chambers and banqueting facilities, architectural considerations precluded the use of standard hard-wired devices. There was also the need for flexibility, to cope with the multi-use nature of the site. For example, smoke generators are a regular feature of the rock concerts held at the venue, so the fire system had to be capable of distinguishing between transient triggers and genuine fires.
Bryan Pope, Portsmouth City Council’s Fire Advisor, explains: "I was concerned by the occasional lateral spread of smoke to areas around the auditorium and the need to mitigate disruption to those attending a concert and other building users. The new system had to be flexible without compromising the safety of the building or its occupants."
Using Apollo technology, Christie Intruder Alarms was able to select products to meet these specific requirements and deliver a fully compatible fire system that did not compromise on performance or reliability. Apollo’s analogue addressable XP95 and Discovery devices form the basis of the fire protection system.
Some 600 XP95 devices were used to protect the main areas of the building, while Discovery ionisation detectors were used in areas where there was the possibility of smoke entrainment. Those installed at the Guildhall are set to Mode 4, so that their sensitivity levels are appropriate to the risk in these areas. Beam detectors were used in the auditorium roof void, high level plant rooms and the Council Chamber. For the heritage areas, Christie Intruder Alarms used Apollo’s wireless XPander range.
A key switch facility enables the stage manager to switch the smoke detectors in the auditorium to ‘heat only’ mode when smoke generators are in use. Operating the key switch also isolates the high level beam detectors in the roof void. A second key switch facility controls the door ‘hold open’ devices around the auditorium.
The fire system is configured in 32 zones and controlled by an eight-loop Advanced Electronics MX 400 control panel. The system is monitored at the ground floor reception and by front-of-house staff during functions. Interfaced with it is a Scope emergency pager system that alerts designated staff if an alarm is raised and transmits information about the alarm zone and device operated. This enables staff to investigate incidents prior to an evacuation being instigated and avoids unnecessary disruption to the occupants.
Fire cover was maintained throughout the changeover. Colin Langdown, General Manager of Christie Intruder Alarms, sees Apollo as being central to the successful completion of this project. "Despite all our experience and expertise in designing installations of this nature, it would not have been possible to overcome the challenges of this project without the versatility and flexibility of the Apollo range," he said.
Following the successful completion of the Guildhall fire system, the Council is now looking to replace the fire detection and alarm system in the Civic Office on the opposite side of Guildhall Square using Apollo technology.