This very large complex of buildings provided a significant challenge, obviously, it was built several centuries before 'building controls' were even thought of!
The main 'church' is protected in part by Point Detectors, but mainly by an aspirating system which draws air through pipes to one of several 'detector' units. These pipes draw the air from many points at several different levels; this is necessary to allow for the fact that air stratifies with the different temperature levels in the building.
Signals from the aspirating system are fed back to an analogue addressable control panel located in the vestry.
Critical to the installation was the need to ensure that none of the detection equipment was visible to the users of the building. It was also essential to ensure that the ancient stonework was not interfered with, marked, damaged or defaced.
Obviously, being a church, candles and incense are used, the system therefore needed to be very flexible yet simple manage for special occasions.
Other parts of the building complex are protected by point detectors. Again the need to ensure that cables etc were not visible was a prime consideration.
In some of the larger rooms it was not practicable to fit point detectors so 'beam detectors were used. These devices can see smoke over a distance of up to 100 metres, each beam covering a corridor of 15 meters width. Instead of having cables running over the ceiling area, a beam of light invisible to the eye is transmitted across the space to a receiver device. Any smoke particles in the intervening space can be detected and a signal transmitted to a control panel.
The physical size and the need for a significant number of detection devices necessitated the need for several analogue addressable control panels. These control panels are 'networked' allowing cathedral staff to interrogate and control the fire alarm system from any of the control panels.
The nature ofthe building, it's use and often the high profile people who attend it, means that false alarms are simply not permitted.
As a result of good design, careful selection of equipment together with good site management, there have been no false alarms from the system.
Visit the Kidde Fire Protection site to view their comments on this project.