Fri, Dec 14, 2012 - Page 8 News List

Tunneling experience gets ignored in project

By Hochen Tan 賀陳旦

According to a Dec. 4 United Daily News report, the Ministry of Transportation and Communications’ (MOTC) Directorate-General of Highways said that although the smoke baffle plates in the new Suhua alteration tunnel are similar to those in Japan’s Sasago Tunnel — whose ceiling recently collapsed — there was little risk of a similar disaster occurring, because engineering technology has improved since the Sasago Tunnel was built.

However, sound engineering is not always enough to guarantee safety: On-site maintenance is more important for disaster prevention, and for reducing injuries and fatalities if one does occur. The group responsible for the Suhua alteration project should use the Sasago collapse as an opportunity to explain the tunnel’s safety measures, to give people intending to use it peace of mind.

A lesson can be learnt from Taiwan’s most recent disaster: the May 7 Hsuehshan Tunnel fire. The Hsuehshan Tunnel utilizes the highest standards of highway design, featuring a third lane running parallel to the traffic lanes along its entire length that is exclusively for use in emergency evacuations or rescue operations. Robust precautions notwithstanding, there were still two fatalities in the fire and 34 people were injured. The official investigation report said most of these injuries resulted from the chaos immediately after the accident. The emergency doors drew in thick smoke, filling the emergency tunnel with fumes that many people inhaled while trying to escape.

The ministry invited overseas experts to Taiwan on July 27 to discuss possible improvements. More than one mentioned that Taiwan should no longer rely on conventional water mist fire-fighting systems. The experience in Europe over the past few years has been that the prevention of smoke inhalation is key to preventing casualties and fatalities during fires. The problem with water mist systems is that the water sprayed from ceiling nozzles during fires makes the tunnel floor wet and slippery. In addition, smoke particles in the air that could otherwise have been removed by extractor fans mix with the water mist and fall to ground level, impeding visibility and hampering attempts to escape.

The lessons learned are clear, yet are not being adopted in the Suhua alteration project. The team responsible for the project has said that they would still follow the original MOTC guidelines and regulations, and would install a water mist fire protection system. If they are going to just go along with the existing regulations, why call an emergency meeting with overseas experts?

The Sasago tunnel accident highlighted another concern: Tunnels are demanding, expensive construction projects, and long ones are particularly complex and costly. Even in Japan, with its high engineering standards, checks and maintenance are sometimes inadequate. The point of the approximately 24km Suhua tunnel alteration project is to give local residents a safe route home. However, we have seen before that enthusiasm for public construction projects is later often matched by recalcitrance in paying for maintenance and repairs.

The Directorate-General of Highways has to work within a certain remit and a given budget. There are many tunnels along the section of Highway No. 9 between Suao and Hualien. Those responsible for the project are going to use systems that experience has shown to be ill-advised. What standards are to be applied to their maintenance and with what funds? How are people traveling home to have peace of mind when they know the tunnels have old designs and are inadequately maintained?

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