FIRE ALARM SYSTEMS | ROYAL PAPWORTH HOSPITAL THE DETECTORISTS Royal Papworth Hospitals fire alarm system has 1,900 fire detectors and more than 4,000 addressable devices. To ensure such a large system was integrated properly, fire specialists had to work with the designers at an early stage in the design, says Static Systems Chris Smith H ospitals are among the most complex buildings for which to design fire alarm and management systems, with designers having to take account of multiple firecompartmentation zones, departmental boundaries, and building use by different groups of patients, staff and visitors. The 1,900 fire detectors installed at the new Royal Papworth Hospital in Cambridge are evidence of the scale of the challenge faced by the projects design and installation team, which comprised fire alarm specialist Static Systems Group, building services engineer Troup Bywaters + Anders (TB+A), contractor Skanska, and the specialist suppliers of the BMS and ductwork. As well as the detectors, the system has 15 networked fire alarm panels and, in total, more than 4,000 addressable devices. The size and complexity of the project meant it was important that the design team worked together at an early stage. The fire alarm system had to interface with dampers, air handling plant and smoke extractors to provide an integrated system that manages the airflow and smoke extraction, to direct smoke safely through the building. At the preconstruction phase, Static Systems and suppliers engaged closely with Skanska and TB+A, who provided the brief. As a result, the design work was completed well before groundwork of the building had been finished. Hospitals have their own bespoke cause and effect, which has to take account of the building design in terms of fire compartmentation (zones), departmental boundaries and building use. For Royal Papworth Hospital, the cause and effect design is one of phased evacuation, where zones adjacent to the one in alarm both vertically and The disabled refuge system at Royal Papworth Hospital horizontally sound an alert signal. Integral to the basic operation of the alarm devices and sounders and beacons is the need to control the supply and extract air intake system. This requires dampers to be programmed alongside the cause and effect, to ensure dampers function consistently with the fire alarm operation. The smoke dampers are designed to work automatically. However, there are specific areas such as basements where a manual extract override key switch allows the fire brigade to operate and control a cold smoke-extract system. It was important that detectors were placed away from air vents, and that clashes with lighting and sprinkler units and pipework were avoided. This was achieved through Skanskas integrated CAD models and associated coordinated ceiling plans, which also ensured the mounting of devices did not block access to other plant, such as fan coil units. Royal Papworths fire alarm system interfaces with other equipment, including the security and nurse-call systems, and sprinklers. Connecting with several systems where a simple on/off control is required is achieved through volt-free contacts. The security system at Royal Papworth integrates with the fire alarm on a floor-by-floor basis, to release door locks and activate other devices. To maintain security integrity, certain more sensitive areas have different operations in the event of a fire condition. The connection to the nurse-call system is via an IP link, which allows more detailed information about the fire or alert to be sent to nurse-call indicators at the nursing stations. Static Systems designed the fire system so that it would pick up signals from the sprinklers flow switches and display them on a bespoke indicator. This also gives information on other plant that the sprinkler system monitors, including water and oil tanks. All alarms, alerts and other messages are directed to the onsite FM or fire-response team via indicators in locations such as security centres and the switchboard. Evacuation planning was also a key consideration when designing the fire-engineered system for the new hospital. In the event of a fire, hospitals typically have a phased evacuation, whereby the affected zone is evacuated and adjacent areas are given an alert. At Royal Papworth, however, the Trust wanted to create a bespoke operation for ward areas. Each ward area goes across more than one of the fire zones for the building, so the Trust asked for an evacuation process based on ward areas rather than fire zones. Static Systems also programmed and supplied a PC-based interactive data station for the fire alarm system. This enables maintenance teams to get an overview of the health of the system, obtain information on devices and, where required, isolate, add or relabel devices. CJ CHRIS SMITH is head of project delivery at Static Systems 36 July 2020 www.cibsejournal.com CIBSE July 2020 p36 Papworth fire alarm.indd 36 19/06/2020 19:22