WITH hindsight it seemed all too predictable that a fire on the Kitzsteinhorn
ski train would end in tragedy. The train ran in a steep, narrow tunnel, making
escape difficult. It had only two fire extinguishers. There was no sprinkler
system. There was no evacuation plan.
All tunnels are vulnerable to fire. When a fire starts in a confined space,
temperatures soar and dense fumes often make escape impossible. But the steep
gradient of the Austrian tunnel made it especially vulnerable. Any fire in a
sloping tube will burn ferociously and spread rapidly because of the 鈥渃himney
别蹿蹿别肠迟鈥�
(see p 4).
So far the number of dead has reached 159.
In most disasters there is a chain of events in which one mishap leads to
another. Each link in the chain is seemingly insignificant but add them together
and the result is horrific.
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Thirteen years ago 31 people died in the fire that raged up the sloping
escalator shaft at London鈥檚 King鈥檚 Cross underground station. The fire was
started by a carelessly discarded cigarette. Several links in that disastrous
chain have now been removed: smoking is banned on the underground, for example,
and metal escalators have replaced the old wooden ones.
The spark that ignited the Austrian catastrophe may never be known. But the
railway could have taken steps to reduce the risk of fire spreading. Skiers
could have been banned from carrying inflammable materials. Although the train
was 鈥渇ire-resistant鈥�, its body was made of an aluminium alloy that would have
burnt when temperatures reached about 650 掳C鈥攚hich they can easily do
in a tunnel fire.
The tunnel should have had an automatic sprinkler system. Sprinklers, after
all, are normally required by law in other vulnerable structures, such as
high-rise buildings. A simple plan telling people to escape down the tunnel, and
not up, would probably have saved lives.
Most main road and railway tunnels have gradients well under 10 per cent and
are not vulnerable to the chimney effect. But for long, steep tunnels there is a
strong case for an additional safety measure鈥攁 separate escape route.
The gently sloping Channel Tunnel, for example, is actually three
tunnels鈥攖wo main bores to carry the trains and a third for use in
emergencies. Its ventilation system is maintained at a higher pressure than the
running tunnels to create an escape route that should always be free of smoke.
The value of this system was proved in the fire of 1996. It was a serious fire,
but the bottom line is that no one died.
There is no guarantee that a similar escape route in Austria would have saved
lives. And building even a small second bore or some other escape route would
have made the tunnel far more expensive. But the human price of not taking this
precaution is too high.
