At 3pm on Thursday 24th December 1953 the daily Auckland express left Wellington railway station carrying 258 people, many beginning their annual Christmas holidays. The train consisted of the 145 tonne, 1400hp steam locomotive Ka949 pulling 5 second-class carriages, 4 first-class carriages and 2 vans.
A Lahar Damages the Tangiwai Rail Bridge
At the summit of Mt Ruapehu, an active volcano in the central North Island, snow melting in the summer temperatures had raised the level of the Crater Lake to overflowing. At about 10pm on Christmas Eve 1953 the wall of the Crater Lake collapsed releasing millions of tonnes of water, ice and mud into the headwaters of the Whangaehu River. The resulting lahar swept down the river and 15 minutes later a 6m high wave carrying mud, rocks and trees slammed into the railway bridge at Tangiwai undermining and dislodging the massive supporting concrete piers.
A Passer-by Tries to Avert a Disaster
Five minutes later and a hundred metres further downstream Cyril Ellis discovered that the road bridge was submerged under turbulent yellow water. He took his torch from his truck to take a closer look and noticed the headlight of a train approaching from the south. Realising the rail bridge could also be damaged he climbed up the railway embankment and ran along the track shouting and waving his torch, trying to warn the engine driver or fireman of the danger. But they did not see his torch or hear his shouts above the roar of the locomotive and the river. The express sped past at about 65km/hour and on to the damaged bridge.
The Express Plunges into the River
The sagging and severely weakened bridge collapsed under the weight of the locomotive, its momentum carrying it almost to the opposite river bank 35m away. Five passenger carriages followed the locomotive into the river and a sixth teetered on the edge of the broken bridge before following the others into the river. The carriages were rolled and twisted by the force of the lahar – four carriages were mangled and stripped to their underframes. One carriage was carried 2½ km down stream.
Tragedy and Heroes
The disaster claimed the lives of 151 men, women and children, including the engine driver and fireman. Bodies were recovered from the wrecked train and the mud and silt of the riverbanks, many over 20km from the scene of the accident. Some were swept 160 km down the entire length of the Whangaehu River to be lost forever at sea.
Many acts of selfless bravery by rescuers were recognised with commendations. Cryil Ellis received the George Medal.
A Nation in Mourning
Throughout New Zealand Christmas Day church services were overshadowed by the disaster. Queen Elizabeth II, on a Royal Tour of New Zealand, extended her Christmas Day radio broadcast to the Commonwealth and Empire to include a message of sympathy to victims and mourning relatives and friends.
On 31st December 1953, 21 unidentified victims were laid to rest in a mass grave at the Karori Lawn Cemetery in Wellington. A memorial was unveiled at the grave in 1957.
Early Warning Systems
After the Tangiwai disaster an electronic river monitoring system was installed with sensors in the Whangaehu riverbed upstream of the bridge and near Mt Ruapehu Crater Lake. These are monitored continuously to provide early warning of unusual river flows to prevent any possibility of a repeat of the disaster.
In Lasting Memory
For many years an annual commemoration took place on Christmas Eve as the Wellington to Auckland express crossed the Tangiwai Bridge. The engine slowed to walking pace and the engine driver cast a floral tribute into the Whangaehu River in remembrance of all those who died at Tangiwai on Christmas Eve 1953.
Today the only visible reminder of the disaster is a memorial plaque by the riverbank between the rebuilt rail and road bridges. The memorial incorporates a replica of the nameplate of locomotive Ka949.
Tangiwai, in Maori, means weeping waters.