it in action - Streaming
video - Thermal image video footage of independent trials
shows comparison of exit behaviour with and without DSE.
Despite advances in Fire Detection
systems to detect fires, these systems do nothing to actually
guide people to safety. They rely on people's ability to find
their way out using exit signs.
a smoke filled area, the emergency exits and signs may be impossible
to locate by sight and an alternative method of guiding people
along the nearest escape route is imperative.
Voice Evacuation systems can tell people where to go, but not
show them how to get there.
use of directional sound to mark exits enables identification
of exit locations that are obscured. Additionally, under non-smoke
conditions, the use of The Localizer®
Directional Sound Evacuation (DSE) beacons draws attention to
Emergency exit signs and nearest exits which are often ignored
because they are so familiar and not normally important.
The Localizer® "audible exit sign" enhances fire
alarms and lighting systems, and we are licensing the technology
to multinational companies in North America and Europe. Research
observed by the British Government has shown that The Localizer®
can reduce evacuation times by as much as 70% in smoke and 35%
in perfect visibility.
sound-equipped beacons are obviously advantageous to people
with visual impairment, and have also been shown to benefit
individuals with learning difficulties and hearing loss. The
broadband sound, which is totally independent of language constraints,
consequently makes the beacons suitable for all nationalities.
fire safety industry has its roots in over a century of tradition
and is, by its very nature, somewhat conservative. Many "accepted
facts" of the industry are based on little or no research.
Here are a few of the myths - and what research teaches us:
People do not travel through smoke when evacuating.
Given the choice, naturally people will avoid going through
smoke, however people
escaping fires frequently have to travel through areas filled
According to Prof J.L. Bryan of the University of Maryland who
studied survivors from 400 different fires, 53% of survivors
from fires admitted to travelling through smoke. P.G. Wood of
the Building Research Establishment in the United Kingdom reported
similar findings. In the September 11th World Trade
Centre tragedy, approx 90% of the occupants survived, however
people struggled to find emergency staircases because the entrances
were from a lobby that was filled with smoke.
Using new types of lighting can dramatically improve visibility
carried out by the Building Research Establishment (UK), using
volunteers in theatrical (white) smoke illustrates how visibility
of different types of exit signs vary in smoke. It ignores the
effect of real smoke on the eyes, or toxicity, however it does
illustrate that NONE of these technologies is visible at over
1.5 metres in dense smoke (Optical Density 3m-1).
At Optical Density 1m-1, the best technology was
visible at just 4 metres whilst Photo-luminescent signs were
visible at just over 1m.
is not affected by smoke.
Smoke rises to the ceiling and people evacuating can bend or
crawl to safety in clear air, breathing normally underneath.
is true that smoke rises when mixed with hot gases, F.R.S. Clark
density is not always lowest near the floor. Smoke tends to
travel along the ceiling when it mixes with hot, buoyant fire
gases. As these gases cool, however, the smoke sinks and eventually
fills the entire space. Smoke may also be dispersed evenly through rooms by
forced ventilation systems and by the action of sprinklers activated
by the fire. Under these conditions low placement of exit signs
may offer little advantage”. (Clark,
F.R.S. Strategies for improving visibility in fires. Institute
for Research in Construction, National Research Council of Canada,
Canadian Building Digest 246, January 1988, 4pp.)
mist extinguishing systems cool hot gases close to the seat
of the fire - breaking down stratified smoke layers and
the "safety gap" at floor level.
Shipp, Senior Inspector of Building Research Establishment,
also confirms that " whilst smoke may be stratified
in a still air environment, the movement of people through the
area can quickly disturb this stability and result in smoke
down to floor level".
Dusseldorf Airport fire
- official report extract:
victims did go by lift from the parking lot on the roof top
directly into the deadly smoke. When the door opened, the dense
smoke hindered the light beam so that the lift doors could not
be closed again. The nearest exit was 3 metres away from some
of the victims but they could not find it and died."
Channel Tunnel fire - official
"The driver of the incident train was unable to leave
his cab to organise the evacuation of passengers because the
smoke was too dense. The Chef de Train was unable to find the
evacuation route within the tunnel because of the thick smoke
and decided to keep everyone on-board the incident train until
the arrival of the emergency services".
Scandinavian Star fire
- official report extract:
"We do know that emergency lighting and marking signs
do not help to distribute people among the evacuation routes
The committee recommends that
a requirement be introduced that audible signals with
a sound that clearly distinguishes them from the alarm bells
be installed by the exit doors in escape routes on board
passenger ships, as directions for escape in conditions
of reduced visibility."
Note: This recommendation was pursued by Governments
of UK & Germany in their proposal to the United Nations
Aircraft fire - official
"Many survivors spoke of their inability to see due
to the extreme density of the smoke and chemical effects on
addition it is also apparent that the effect of such atmospheres
is to rapidly suppress any ability of those affected to shout,
due to respiratory and acidic gas 'burning' effects on their
These sensory deprivations might be effectively
countered by the use of automatic audio-attraction devices to
guide evacuees towards viable exits. Research should be undertaken to assess the viability of 'audio-attraction'
and other techniques designed to attract passengers towards
viable exits when speech and vision is impaired in smoke
and toxic/irritant gases."
by Professor Deborah Withington - The Use of Directional Sound
to Aid Aircraft Evacuation
Myth: Low Location Lighting guides to safety
Reality: What research was done prior to its introduction? There are limitations to
- It cannot provide guidance in open spaces
- In normal installations it cannot show which
way to the nearest exit.
- In smoke, eyes are attacked so its visibility
- Electro-luminescent systems are very expensive
- Photo-luminescent systems are largely invisible
Nieuw Amsterdam fire
the time the passenger re-entered the corridor, it had become
filled with smoke. Crouching to move along the corridor, the
passenger became disoriented and was eventually found by a crewmember
and taken to safety. The ship’s electroluminescent low-location
lighting system was in operation."
Aircraft fire - official
"Against this background of research and survivor evidence it
is difficult to substantiate the rationale behind current regulatory
moves towards the introduction of low-level 'escape-path' lighting
to assist evacuations from smoke filled cabins. Under
such circumstances the net safety-gains from such a requirement
are likely to be minimal unless the passengers' eyes are protected.
awarded the Fire Industry Council's Innovative Product
Award and the Royal Institute of Naval Architecture ~ Lloyds
Register Safer Ship Award,
DSE beacons are the result of over 7 years of research
with a substantial body of independently
verified trials which have shown its effectiveness in a
number of different environments:
Summary fact sheet on Directional Sound Evacuation (236k pdf)