09.09.2013/Rog ITS 2013 1

SIMPLE AND RELIABLE FIRE

DETECTION IN ROAD TUNNELS

Dr. Arnd Rogner

Metaphysics SA

Actual detection technologies (in Europe)

Field experience in tunnel fire detection

System integration

Contents

09.09.2013/Rog 2 ITS 2013

Road tunnel fire detection technologies (Europe)

09.09.2013/Rog 3 ITS 2013

Line type heat detectors (LTHD)

Measuring heat emission from fire

Visibility monitors / smoke detectors

Measuring smoke density

Video analysis

Reacting on different parameters like stopped vehicles, smoke

density, or open flames

Road tunnel fire detection technologies (Europe)

09.09.2013/Rog 4 ITS 2013

Line type heat detectors

(LTHD)

Absolute temperature

and/or rate-of-rise detection

Temperature profile

Loop installation with 2

control units for increased

availability

Semiconductor and fiber

optic systems

Road tunnel fire detection technologies (Europe)

09.09.2013/Rog 5 ITS 2013

Description:

Temperature sensor cable with

individual sensors in a distance of

4 m to 10 m for road tunnel application

Temperature measurement by

semiconductor sensors using the band

gap effect

Comments:

Threshold of each sensor editable

Reaction in RABT test 30 to 60 sec

No maintenance

LTHD Systems: Semiconductor sensor cable

09.09.2013/Rog ITS 2013 6

Description:

Fibre optic measurement system with

laser (OTDR or OFDR or code

correlation measurement)

Comments:

Different generations with different

specifications on the market

In certain solutions we have a

dependence: spatial resolution –

temperature resolution – length of the

system - detection speed

LTHD systems: Fibre optic sensor cable

09.09.2013/Rog ITS 2013 7

Visibility Measurement / Smoke Detection

Visibility monitors or special smoke

detectors

Description:

Optical scattered light or transmission

measurement

Installation distance 100 … 300 m

Comments:

Low fault alarm rate (scattered light)

Heating system to avoid interference

by fog

09.09.2013/Rog ITS 2013 8

CCTV Based Information System

Description: Pictures of CCTV cameras in

the tunnel are analyzed

Comments: Response speed: high

(smoke and fire)

Alternative: detect stopped vehicle

Non-negligible false alarm rate

Manual alarm verification required

Useful for early fire detection in tunnels with high risk potential

09.09.2013/Rog ITS 2013 9

LTHD specified in most countries for tunnel fire detection

E.g. DE, CH, AT, ES, CN, KR, TW, SP, BR, CO,…

Several countries request smoke detection in addition

E.g. DE, CH, SK

In addition smoke detection is used in more countries, even if it

is not yet required in a directive

Some countries just request fire detection,

but do not specify the technology

Can be LTHD, smoke, video-based detection

Some countries use no automatic fire

detection

Fire detection in road tunnels - guidelines

09.09.2013/Rog 10 ITS 2013

Field experience

09.09.2013/Rog 11 ITS 2013

Fires by accident

Tauern 1999

Gotthard 2001

Gleinalm 2001

Viamala 2006

Fires by defects

Gotthard Ø 4 per year

- Overheating

- Turbocharger damage

- Tire fire

- Blocked brakes

We have different kinds of fire

09.09.2013/Rog 12 ITS 2013

Most fires start with smoke, before we get

open flames

Tauern and Gotthard fires would have

been detected earlier by smoke detection

Pool test fires in this sense are not

mirroring the reality

Smoke is faster than heat

09.09.2013/Rog 13 ITS 2013

Test # Fire size Wind

velocity

Detection time

smoke

detectors

Detection time

LTHD

1 0.1 MW 1.6 M/S 2:13 2:24

2 0.5 MW 1.6 M/S 1:29 1:07

3 1 MW 1.6 M/S 1:34 0:34

4 0.1 MW 1.15 M/S 1:25 1:23

5 0.5 MW 1.15 M/S 1:10 0:53

6 1 MW 1.15 M/S 0:57 0:25

7 CAR FIRE 1.55 M/S 0:52 2:53

8 3 MW POOL 1.8 M/S 1:23 0:25

Smoke is faster than heat

09.09.2013/Rog 14 ITS 2013

Results of Runehamar tests 2007

From: ARALT, T.T., NILSEN, A.R. (2009): Automatic Fire Detection in Road Traffic Tunnels;

Tunneling and Underground Space Technology, Vol. 24/1, pp.75-83

In case of a real car fire, smoke detectors can be

(significantly) faster than thermal detection

Pool fires give nice reproducible test conditions for

approval and test of system, but they are not mirroring

the reality of a car fire

In case of fires after accidents with fuel spills and

instantaneous developing open fires, the thermal

detection will be faster

Smoke is faster than heat

09.09.2013/Rog 15 ITS 2013

What happens, if a burning vehicle

continues to drive?

Truck drivers are even trained to

do so

How will our detection system

react?

Moving vehicles in fire

09.09.2013/Rog 16 ITS 2013

Moving vehicles in fire

09.09.2013/Rog 17 ITS 2013

Location

Time

Turbocharger damage

in Gotthard tunnel

From: GRÄSSLIN, URS (2010):

Erfahrungsbericht Rauchdetektion

aus dem Gotthardstrassentunnel;

Proceedings of 9th Symposium

„Sicherheit im Strassentunnel

durch Einsatz moderner

Messtechnik“, Sigrist-Photometer

AG, Geroldswil

Localization by smoke is more difficult, as smoke is

spreading over a certain distance

More complex algorithms are required to control the

ventilation

CCTV cameras might be

blind due to high smoke

density

Temperature detection

is the only way to identify the

position of the burning

vehicle

Moving vehicles in fire

09.09.2013/Rog 18 ITS 2013

Temperature

Smoke

Important properties of thermal detection

09.09.2013/Rog 19 ITS 2013

Avoiding fatalities in tunnel fires is

mainly driven by self rescue

Simulations show that the number of

fatalities is proportional to the

detection time of the fire (or in fact to

the time informing the users and

their reaction)

If we reduce the detection time, we

also can reduce the number of

fatalities

Importance of fast detection

09.09.2013/Rog 20 ITS 2013

Tunnel Test 1 Test 2 Test 3 Test 4

Felderhalde 37 s

5 MW, 5m/s

- - -

Kohlberg Nord 31 s

5 MW, 6m/s

52 s

2.5 MW, 3m/s

ca. 60 s

5 MW, >6m/s

-

Kohlberg Süd 50 s

5 MW, 6m/s

52 s

2.5 MW, 3m/s

44 s

5 MW, 6 m/s

58 s

2.5 MW, 3m/s

Stauffer - 28 s

5 MW, 6m/s

52 s

2.5 MW, 4m/s

50 s

1.25 MW, 2m/s

Schwetzingen -

26 s

5 MW, 6m/s

- 26 s

5 MW, 6m/s

Ditschhardt 36 s

5 MW, 6m/s

70 s

2.5 MW, 2m/s

Fast detection – approval test fires in Germany

09.09.2013/Rog 21 ITS 2013

5 MW Brand according to RABT

Fast detection – test fire Ditschhardttunnel

09.09.2013/Rog 22 ITS 2013

After detection the smoke valves and/or

supression systems are triggered

The zone length typically is 100 m for smoke

valves and 25 m for supression systems

The adressing of the correct zones is crucial

for the lifes of the users

Influence of air speed

Detection of radiation heat

Influence of drift for FO systems

Needs regular recalibration

The precise localisation is important

09.09.2013/Rog 23 ITS 2013

Precise detection – test fire Ditschhardttunnel

Temperature profile MHD 535

09.09.2013/Rog 24 ITS 2013

Precise localisation of the fire

09.09.2013/Rog 25 ITS 2013

Absolute temperature threshold at 60°C

Backup

Gradient threshold at 3°C / 20 sec (9°C / minute)

Standard reaction type in real fires and tests

Dual-detector-dependence helps to reduce false alarms

- 1 sensor has to have 2 alarms in sequence

- 2 sensors give alarm at the same time

Under difficult conditions (e.g. sunlight at entrance), the gradient

condition can be increased up to 5°C / 20 sec

Alarm criteria for thermal detection

09.09.2013/Rog 26 ITS 2013

Systemintegration

09.09.2013/Rog 27 ITS 2013

System integration fire detection: Example D / A

09.09.2013/Rog 28 ITS 2013

Tunnel monitoring and control system

Alarm activities:

- Ventilation

- Escape Lights

- Fire Brigade

- Closure

- …..

FAP

PU

FAP

PU

GW

LTHD

Relays

Building Fire Detection

Manual Callpoints Tunnel

Fire extinguisher contacts

etc.

Redundance

Ala

rms

Ala

rms

Tem

pera

ture

-

valu

es

Sm

oke d

ete

ction

System integration fire detection: Example CH

09.09.2013/Rog 29 ITS 2013

Tunnel monitoring and control system

Alarm activities:

- Ventilation

- Escape Lights

- Fire Brigade

- Closure

- …..

FA

P

Build

ing,

etc

.

PU PU

GW

LTHD

Ala

rms,

Tem

pera

ture

-

valu

es

GW

Redundance

Sm

oke d

ete

ction

Challenge

Different system architecture in different countries (projects)

Partly using different interfaces / protocols

(Modbus TCP/IP, Profibus, IEC 60870-5-104, …)

This requires different integration concepts and components

The cost for the integration part is increasing

Redundancy for all signal / information transmission

Standardization would make sense

System integration fire detection

09.09.2013/Rog 30 ITS 2013

Thermal detection is mandatory. It is the most reliable method and

the only one to localize a fire in case of a smoke-loaded tunnel

The thermal detection can localize a fire within 10 m (or even less)

For the selection of a linear heat detector, reaction time, precision of

localization, and maintenance effort should be regarded

Smoke detection is a recommended addendum, as small car fires

are seen significantly faster. Users can win several minutes to

escape

A standardized integration concept could reduce cost

Conclusion

09.09.2013/Rog 31 ITS 2013