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Intersec Fire Safety Conference: Dealing with fires in tunnels

Dr Gunnar D. Jenssen, Senior Research Scientist, Project manager, SINTEF will be delivering a presentation entitled ‘Dealing with fires in tunnels’ as part of Intersec’s Fire Safety Conference. Discover some of the key issues that will be discussed in the short interview below.

What makes tunnels particularly dangerous when dealing with fire risk?

Road tunnels are one of transportation’s most complex and intriguing forms. Encountering an emergency such as a fire in a tunnel presents a situation that few people have encountered before.

The intersection of physical conditions (closed built form, fire/heat/ smoke, vehicles each with its own closed space), social conditions (predisposition to save investment in auto), environmental factors (tunnel safety conditions), and human behaviors (disbelief, control response, panic) is compelling. And unique.

As a result, adding the need for emergency evacuation –usually self-evacuation, due to urgency and delayed response times by emergency rescue teams creates a potential for catastrophic outcomes.

Here in the UAE there are several very long tunnels – what are the best fire protection practices that can be applied to these tunnels?

The basic safety lies in the physical design of the tunnel. There is a continuous debate about the use of automatic water deluge or water mist fire suppression systems. There are pro’s and con’s to effectiveness, maintenance and cost.

While in fact the most cost effective way to save lives in a large tunnel fire is to ensure effective emergency exit systems for road users. Smoke and smoke spread is the big threat. Tunnel fire ventilation may add to this threat or ease the situation for road users trapped in the tunnel fire.

In order to ensure optimal safe use of ventilation in a fire you need to have safety systems that tell tunnel operators how many vehicles there are in the tunnel and where vehicles are in relation to the fire. Scenario based contingency plans and scenario based exercise of all personnel involved in an incident will help ensure thing’s function as planned when a tunnel fire takes place.

What are the worst tunnel fires that you have experienced and what are the main causes of tunnel fires?

No doubt the Mont Blanc tunnel where 39 people died stands out as the worst tunnel fire in recent decades. In addition the tunnel refurbishment took 2 years with the societal costs involved when one of the main European transport links was shut down.

Personally I have been involved in the post fire investigation in the Oslofjord 7.2 km subsea tunnel in 2011, where 34 road users were trapped in smoke and recently with post fire investigations and in-depth interviews of all 67 road users trapped in the 11.4 km long Gudvanga tunnel in august 2013.

This tunnel fire incident could quickly have evolved to a catastrophe, but the burning truck was without cargo. The main cause in all the recent large road tunnel fires has been truck fires. A fire in an ordinary car is manageable, but truck fires due to overheating etc. represent a fire potential in MW, with potential catastrophic damage to lives and tunnel construction.
If the truck carries dangerous goods the damage may have an even larger area of influence. Truck fires have also been the end result of tunnel accidents were a small incident evolves to a catastrophic tunnel fire. Hence reducing the risk for tunnel accidents reduces risk of tunnel fires.

How prone are UAE and wider Middle East tunnels to catching fire given the more extreme environments?

Truck fires are often caused by overheating, lack of maintenance or lack of driver competence. Environmental conditions and traffic culture may represent and added risk in UAE and the wider Middle East. In addition there is the risk road tunnels may be subject to acts of terror.

The Salam tunnel in Abu Dhabi is 4.2km – how would authorities deal with a fire if one broke out?

My knowledge of this tunnel is very limited; hence it is unwise to give advice without knowledge about the tunnel as a potential fire object. What are the physical tunnel facts, technical safety installations, emergency exit systems etc.

Whatever the answer to that is, one should ask oneself what is the first priority in a fire incident? Mitigating the fire, saving the tunnel construction or rescue people?

Have you worked with any tunnels previously in this region? If so, please give details.

No, not in the UAE or the Middle East region, but I have previously been project manager for Safety and security in the world’s longest twin tube tunnel. The 18.2 km long Qinling Zhognansan tunnel in China and I have a long record of international projects.

Ongoing international work is on underground Safety of Earthscrapers in Singapore together with Nanjing Technical University and on Emergency Exit Signs and Systems for Highway Tunnels as a sub consultant to Texas Transportation.

Finally, how significant is it for you to be speaking at the Intersec Fire Safety Conference?

It is an important venue to share expertise in tunnel fire safety and learn more about the challenges you face in UAE and the Middle East area in terms of fire safety.

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