Against the backdrop of a number of major fire related incidents including the Mont Blanc Tunnel in 1999, which claimed the lives of 39 people, a funicular railway tunnel fire in Kaprun, Austria, two years later where 155 sadly died, and in March this year a fatal fire in the Melbourne City Link Tunnel; there has been increasing interest in the application of CCTV cameras in conjunction with video analytics technology, specifically video smoke detection, to provide vital early warning of incidents. The very nature of the confined tunnel environment means that any delay can prove critical when it comes to the potential for a blaze to be tackled and those in the tunnel to be evacuated.
A key advantage of video smoke detection is the system's ability to make use of existing infrastructure so it can be retrofitted to work with existing security CCTV cameras, simply being installed at the relevant control centre. Here it can apply image processing technology, and extensive detection and known false alarm algorithms, to alert the system operator to the presence of smoke in the shortest possible time. By not relying on the proximity of smoke to the detector, unlike traditional methods, it effectively detects smoke at source so early action can be taken.
This technology underlines the benefits of being able to readily integrate safety critical functions such as fire and security. Video smoke detection is now being applied to protect road tunnels in Italy, service tunnels in Dubai and has been operating successfully over the last year in the Sydney Harbour Road Tunnel.
The capability of this technology was demonstrated during a series of tests in conjunction with the Sydney Fire Brigade involving controlled vehicle fires. Here the video smoke detection system was able to generate its first alarm just 14 seconds after smoke had become visible - impressive by any standards. This was unlike the older conventional systems which had not generated any alarms after 5 minutes and temperatures were in excess of 500°C.
Ultimately, we are likely to see many more examples of CCTV being applied intelligently to deliver benefits beyond security - from fire safety to management information - and offer solutions in areas such as tunnel safety where there are critical gaps in the capability of existing, conventional, alternatives.