TUNNEL VISION

The construction of the Ōtira Tunnel in the Southern Alps is considered one of New Zealand’s great engineering feats – and it’s still inspiring awe 100 years on

Passengers travelling on the TranzAlpine train might barely notice the Ōtira Tunnel – it is, after all, one of many tunnels on the 223-kilometre journey between Christchurch and Greymouth, of which most are unremarkable. The Ōtira Tunnel, however, is not.

An 8.5-kilometre hole through the Southern Alps, the Ōtira Tunnel is one of New Zealand’s greatest engineering feats. Construction began in 1908, and when it opened 15 years later on 4 August 1923 it was lauded as the longest rail tunnel in the British Empire and the seventh longest in the world.

Symbolically and practically it joined Westland and Canterbury by rail for the first time, when previously a nightmarish coach road over Arthur’s Pass had been the only option.

As part of its ‘Engineering to 1990’ project, the Institution of Professional Engineers of New Zealand (now Engineering New Zealand Te Ao Rangahau) deemed the tunnel significant to the development of Aotearoa New Zealand – a significance that is also recognised by the Selwyn District Council.

The importance of the Ōtira Tunnel is not lost at a grassroots level either. For more than a year now, a committee of Ōtira Tunnel enthusiasts from the West Coast and Canterbury has been planning the tunnel’s centenary celebration – and they haven’t been afraid to get their hands dirty in the process.

The committee normally meets every month at Ōtira or Arthur’s Pass, but in the lead-up to the centenary they’ve been undertaking working bees as well. At the Ōtira, or western, end of the tunnel, members have been clearing tracks, removing vegetation from around one of five original survey monuments, and building a replica tunneller’s cottage.

Ōtira Tunnel Celebrations Committee Chair and Co-ordinator Di Gordon-Burns and her husband own an art gallery housed in Ōtira’s old post office. They love where they live – and the tunnel.

“What a privilege to live surrounded by a national park. We couldn’t be luckier,” says Di. “And this town exists because of the tunnel.”

On 4 August 2023, 100 years to the day since the tunnel’s opening ceremony, the group will be joined by others from around New Zealand for celebrations honouring the men who completed the mammoth project.

Plans for the day include a special train from Greymouth, additional carriages on the TranzAlpine train from Christchurch, speeches, exhibitions, a plaque unveiling and bus trips to the Ōtira hillside tunnel entrance.

A specially minted medallion replicating the one presented to Prime Minister William Massey at the opening ceremony in 1923 is being produced and a centenary ball will be held at the Bealey Hotel near Arthur’s Pass.

A book written by Bruce Shalders, the South Island field officer for the Rail Heritage Trust of New Zealand –along with his fellow committee members Di and Chris Stewart – is being produced to mark the centenary.

1. Bruce Shalders and Fiona Neale choose tunnel construction photos for the centennial book ThroughtheAlps

2. Ōtira Tunnel Celebrations Committee Chair and Co-ordinator Di Gordon-Burns at her Ōtira gallery.

3. Committee member Fiona Neale sorts out the photographic displays for Arthur’s Pass and Ōtira.

4. Committee members at the site of the original construction workshops near the tunnel mouth at Ōtira.

5. Ōtira

“The tunnel was a marvel for its time,” says Bruce. “So many men worked from both ends for 15 years. Their perseverance in the face of horrible amounts of rain, weeks and months in the semi-dark, breathing foul air, the weather outside, the water inside – it was incredible.”

Long and steep, the tunnel is KiwiRail’s most challenging piece of infrastructure, adds Bruce, and requires emergency safety measures such as breathing gear on board. Locomotives travelling through the tunnel have two sets of breathing gear in each cab, and six identical kits are stationed in cupboards along the tunnel. While an emergency event inside the tunnel is highly unlikely, the walk out could take some time through foul air and, at times, fog. The tunnel is remarkable in that it’s still used for the purpose for which it was built, he says, and 3.5 million tonnes of machinery and freight travel through it annually.

At the Arthur’s Pass, or eastern, end of the tunnel, committee member and motel owner Fiona Neale is creating a large-format photo exhibition for display in both villages during the centenary. She and Chris recently gave two talks on the tunnel to locals, and she says while many know about the tunnel’s importance, they perhaps don’t know much of its history.

“We have to honour all those men who made it happen,” she says.

Challenging conditions

There are many stories of the tunnellers’ hellish working conditions, but Di has a special interest in the role that women and children played during the construction. In the chapter she wrote for the centenary book, she notes that many workers brought their families with them. They lived in three-room cottages, whereas the single men lived in pairs in tiny huts.

The late Tom Ferguson, whose father worked at the Ōtira end of the tunnel for nine years, said that when his mother arrived with him as a baby, she thought it was the end of the world.

“It rained for weeks, she cried for weeks – she didn’t like it at all.”

Di’s research has revealed that in spite of the rain, cold and snow, and a lack of electricity and running water, life in the tunnellers’ villages (there were three at Ōtira and one at Arthur’s Pass) was not always unpleasant. Despite the muddy conditions, women took great pride in keeping their homes pristine, she notes, and there were shops, a visiting dentist, schools and street names.

For Bruce, it is the technology used to construct the tunnel that is particularly astounding.

“The project was cutting edge, [using] all the latest techniques that had been studied in Europe. Power stations were built at each end to provide electricity for the compressed air drills and for a narrow-gauge railway to take workers in and the [excavated materials] out.”

Five survey monuments, used in geodetic and land surveying, were built in line of sight to the tunnel. That work was led by surveyor John Howard Dobson, and was often hampered by rain, snow and summer heat haze that impaired visibility. His endeavours, however, paid off, with the final alignment varying by only a few centimetres.

The committee has recently cleared a survey monument at the mouth of the Ōtira Tunnel, with only one of the five now remaining to be found, says Bruce. “[It’s] high up in the bush, but we intend to find it.”

Steam locomotives couldn’t use the tunnel due to its steep grade, he says, so electric traction was pioneered (in New Zealand) in the tunnel. The system was only replaced in 1997, when the introduction of diesel engines meant the run between Westland and Canterbury could be made with no stops to change systems.

Still rolling

These days, it’s the job of Anit Lal and his team to keep a professional eye on the tunnel. Anit is the Field Production Manager in charge of the Midland line for KiwiRail. His team inspects the line, including the tunnel, twice a week.

“The steep grade has special issues,” he notes. “Our vehicles have to have good dual-braking systems. Going up from Ōtira, there are also special arrangements for flushing out bad air.”

Mike Morgan is one of a small group of KiwiRail drivers based in Ōtira who are authorised to drive trains through the tunnel, using four dedicated locomotives called bankers. Mike loves his work and his colleagues – and even the area’s weather.

“In the cab we have a sophisticated monitor to measure oxygen, nitrogen and carbon monoxide levels. We also have a thing that looks like the kit a scuba diver wears, which includes gas bottles and a professional mask.”

A new state-of-the-art communications system installed in the tunnel, he says, has been a great addition. But as Mike attests, even as the tunnel approaches 100 years old, it remains an awe-inspiring piece of engineering.

“With trains limited to 28 to 30 kilometres an hour, it takes a while to get through,” says Mike. “Being very long and dark, it’s not for the faint-hearted.”

Shining bright

When Natalie and Brendan Canton sit in their cottage at night, they summon up the life of a tunneller who sat in the same room, in front of the same fireplace, more than a century ago.

“If we turn off the lights and have the firelight filling the room, we can feel what it must have been like,” says Natalie. “So much hard work, so much toil to create something so important.”

The couple’s Arthur’s Pass cottage was built in 1910, originally to house one of the married men working to construct the Ōtira Tunnel. It’s one in a cluster of one-time tunnellers’ cottages at the western end of the village that were abandoned following the tunnel’s completion in 1923 and eventually sold to private owners.

At only 35 square metres, the Canton’s cottage has four small rooms, including one added in 1935, and a long drop outside. “If it has been snowing,” laughs Natalie, “you have to take a shovel to dig a path.”

When they bought the cottage seven years ago, it was furnished, including crockery, cutlery and linen – some of which dated back to the 1930s.

“We still use it all,” says Natalie, “to honour all the people who loved this cottage before us.”

The pair clearly love their home. Brendan laughs when he talks about repairing the interior wall scrim and sarking, behind which they found a newspaper dated 1910. It would have been too logical to install plasterboard linings, he says; instead, they replaced some of the sarking with fence palings, which happened to be the correct size, and repaired the scrim.

With emotion in his voice, he adds: “When I paint the corrugated iron on the outside walls, I think of the people who’ve done this before me for 110 years.”

The cottage has also been rewired and had its piles replaced and original floors oiled, while the original roll-top tin bath in the external bathroom has been repaired and painted.

“We carefully do all necessary maintenance to protect the cottage from the harsh climate,” says Brendan.

The couple’s work in restoring the cottage was recognised with a Canterbury Heritage Award in 2018. Says Natalie: “We wanted [a home] that connected to the past, to respect what it is, to honour those men.” n