On the 24th of December, 1953, a passenger express train was making its way across New
Zealand from Wellington to Auckland. On board were hundreds of passengers heading home for
Christmas. Many of them would not make it to their destination. Unbeknownst to anyone
on board, the train was speeding towards the worst rail disaster New Zealand had ever seen.
Events leading to the Tangiwai disaster actually began almost a decade before in 1945. It was
in March of this year that Mount Ruapehu on New Zealand’s North Island began erupting…
and kept on erupting on and off for the rest of the year. This volcanic activity damaged
crops, polluted water sources and filled the air with ash and dust all across the North
Island. Residents were no doubt happy when the volcano stopped erupting at the end of
1945. As it normally did between eruptions, the
crater of Mount Ruapehu filled with water. Normally, water from this lake would flow
from the crater and down the slopes of the volcano as part of the Whangaehu River. However,
the eruption had ejected enough material to form a dam across the outlet of the lake,
trapping a huge amount of water in the crater. This water remained in place, its level steadily
rising year on year, until the 24th of December 1953, when the dam of volcanic material finally
disintegrated. Water flooded out, creating a lahar. A lahar is a fast-moving flow of
water, ash, earth and volcanic material that streams downhill like a liquid landslide,
gathering further debris as it does so. This lahar was particularly violent, uprooting
trees and eroding the banks as it rushed along the course of the Whangaehu River.
Spanning the river some distance downstream was the Tangiwai Bridge. This railway bridge,
built in 1908, was supported by a number of solid concrete piers. The lahar slammed into
these full force, completely washing away two of the supports. To give some idea of
the destructive power of the lahar, just a single one of these piers weighed more than
100,000 kilograms (or more than 200,000 pounds). The flow of water, ice and other debris was
strong enough to not only displace them, but to carry them a significant distance downstream.
With the supports beneath it gone, the bridge sagged dramatically, barely remaining intact.
At this time, a man named Cyril Ellis was driving his wife and mother-in-law to his
parents’ house so that they could spend Christmas together. He arrived at the road
bridge which sat alongside the railway crossing at around 10:15pm to find it completely submerged.
Worse still, the railway bridge looked on the verge of collapse. No sooner had he exited
the car to investigate than he heard the sound of the approaching express train, and saw
its lights in the distance. Realising the danger, Mr Ellis grabbed a flashlight from
his car and sprinted towards the approaching train, waving and shouting in an attempt to
warn those on board of the danger. Driving the train was engineer Charles Parker.
Upon seeing Mr Ellis waving frantically up ahead, he applied the emergency brakes, bringing
the train to a screeching halt. Unfortunately, it couldn’t stop quite soon enough - it
ran out onto the unsupported bridge, which gave way beneath it. The engine and five carriages
tumbled down into the swollen river below. A sixth carriage teetered on the brink, prevented
from falling only by its coupling to the car behind it. Mr Ellis, who had witnessed the
entire disaster from the bank, took his life in his hands and boarded this carriage, where
he met the train’s guard and told him what had happened. Before they could evacuate any
of the passengers, however, the coupling holding the sixth car in place snapped, and this car
too plunged down into the river. Despite this 15 metre (or 50 foot) fall, Mr
Ellis and the train guard were able to smash a window and evacuate passengers onto the
roof of the car, from which they were subsequently rescued. Thanks to their actions, only one
person from this carriage died in the disaster after becoming trapped in their seat by fallen
luggage. The other cars which fell into the river saw
much higher death tolls. While some passengers were able to escape, many were not. A huge
number drowned when water flooded into their train carriage, while those who were able
to escape through a door or window risked being swept away by the fast-moving water
– fast-moving water which was not only ice cold, but which was also churned into a muddy,
sulphuric slurry by the lahar, polluted with oil from the train, and filled with deadly
debris that had been picked up by the flood. The five carriages which fell into the Whangaehu
River contained 176 passengers. Only 28 of them survived. Also taking into account the
lone fatality from the sixth car, and engineer Charles Parker and his fellow driver, both
of whom perished in the incident, 151 people were killed, most of them in the first few
minutes after the collapse of the bridge. While rescuers attended the scene, their work
quickly became more about recovering bodies than about saving lives. Even this was no
easy feat. Although the lahar subsided after just an hour, the river was still flowing
powerfully, sweeping many bodies away from the scene. Some were recovered days later
and huge distances away, discovered by farmers where they had washed up on the banks of the
river. For weeks nets were put in place across the mouth of the Whangaehu, in the hope of
catching bodies that had not yet been found. Despite all this, twenty bodies were never
retrieved. It is believed that they were washed out to sea.
While the search for bodies was ongoing, New Zealand was struggling to cope with the shock
of the disaster. Most New Zealanders learned about it by means of a broadcast on Christmas
Day. The announcement cast a dark pall over a day of celebration, with many families plunged
into mourning. New Zealand at the time had a population of just a few million. The death
of more than a hundred people in one incident meant that almost everybody knew somebody
who was in some way affected. An investigation was conducted, and the design
of the bridge was called into question. The crossing had been designed specifically to
resist flooding and the impact of lahars… but it had been built in 1908, based on what
was known then about the size and power of lahars that were likely to impact it. The
lahar that had destroyed the bridge had been many orders of magnitude more powerful and
destructive than had been anticipated back then.
Ultimately, nobody was found to be responsible for the disaster. Everyone involved, it was
ruled, had exercised due care and attention in carrying out their duties. Indeed, many
people had shown immense courage, and were recognised for doing so. Cyril Ellis – the
bystander who had entered the train and helped rescue passengers – was, for example, awarded
the George Medal the following year. The lahar had been a natural disaster – one
that came at precisely the wrong time. Had it struck the bridge just a little earlier
or just a little later, there is a reasonable chance that disaster could have been averted.
It was a matter of chance and bad fortune that the incident had been as deadly as it
was. A memorial to those who lost their lives in
the incident was put in place a few years after the disaster in 1957, close to the place
where it happened. It is maintained to this day.
The Tangiwai Bridge was replaced with a stronger and more modern railway crossing and road
bridge. To prevent another similar tragedy, an early warning system was put in place upstream
from the bridge. By monitoring the water levels in the river and alerting railway staff to
sudden changes in water level, the system provides around 45 minutes warning of any
impending lahar. This system has already seen use. In 2007
a lahar of a similar scale to the one which destroyed the Tangiwai Bridge in 1953 was
detected. Trains were stopped and traffic halted until the powerful flood had cleared
the bridge. Nobody was hurt. Nobody was killed. In the case of the Tangiwai Disaster, although
nobody could be said to be at fault, lessons were still learned and systems were created
to ensure that when the bridge was rebuilt, it was rebuilt safer and more secure than
the one it replaced.