Chain Hills Tunnel

History

Unlike the railways in Europe or northern America, New Zealand tracks were rudimentary. They were built cheaply and hastily using light iron rails that had a narrow 3ft 6in gauge. Even the tunnels and bridges were minimalistic and usually made as small as possible to get the railways up and running as quickly as possible. It was always the intention, though, that the lines would be improved in the future as traffic and available finances increased.

The four-hundred and sixty-two metre long Chain Hills Railway Tunnel, also known as Wingatui Tunnel, was one of the tunnels built in the 1870s, during New Zealand’s brief period of industrialisation. The line itself was constructed to improve transportation of coal and other natural resources across the land to major ports, where the goods could then be shipped elsewhere. Like the Caversham Tunnel, the Chain Hills Tunnel was largely dug out by hand, but it is unique in the sense that it is a Victorian styled brick tunnel that would have taken longer to build than some of the others that were carved out. The Chain Hills Tunnel also sparked much excitement in Dunedin during its construction as workmen made an interesting discovery while making a cutting at the southern end of the tunnel. Thirty-five feet under the ground, which it is thought was once swampland, a large number of moa bones were found (a flightless bird endemic to New Zealand). The bones ranged in shape and size and were in a very good state of preservation owing to the high alkaline levels in the soil.

The Chain Hills Tunnel was completed in 1875. Progress had been aided with the construction of brick kilns at either end of the tunnel, as this meant materials did not run short because bricks were constantly available throughout the project. However, finishing the tunnel proved to be a difficult and dangerous task. For years the project was plagued by regular flooding, which slowed progress, and workers were also encumbered by the hardness of the stone they were cutting through. Alongside these issues, six months before completion a rock fall occurred at the north end of the tunnel. The incident claimed the lives of two men, Patrick Dempsey and Thomas Kerr. A third man was severely injured as both of his legs were shattered, leaving him crippled for the rest of his life. In the end, the tunnel did not remain in service for very long either as it was abandoned in 1914. A new dual-lane tunnel was constructed further south which meant there was no longer any need for the Chain Hills Tunnel.

In the short period of time the Chain Hills Tunnel was operational it claimed another life – that of Irishman George Thompson. Reports indicate that late one evening in 1895, George took a shortcut through the tunnel to get home. Although there are several niches in the tunnel it is likely George was unaware of them, or simply too far away to reach one, before he noticed the oncoming train. Since its closure, however, no more lives have been lost. For a while the tunnel was used as a popular way of passing between Abbotsford and Wingatui, and for moving sheep between the two locations. Nevertheless, since the 1980s the tunnel has been closed to the public due to the deterioration of the tunnel’s structural integrity and subsequent health and safety concerns.

In recent years there have been plans to redevelop the tunnel into part of the proposed Otago Central Rail Trail (a cycle and pedestrian track). But, due to lack of funding and ongoing concerns surrounding the structural integrity of the tunnel, especially with the increased risk of it being damaged by an earthquake, the project has come to a standstill. The only recent work Dunedin City Council has carried out on the Chain Hills Tunnel has been to shift two vents from sewer gas reticulation pipes, to stop them from venting into the tunnel.

Our Version of Events

Having just returned from a South Island trip the previous night, we had no intentions of going exploring, until Nillskill rocked up that is. He was passing back through Dunedin so we decided while he was around to have a crack at the old Chain Hills Tunnel that’s been on the cards for quite a while. We understand there was a public open day a few months ago, but going to an event like that would take away one of the most interesting parts of exploring – figuring out how to slip into these places.

We loaded up the car with the usual gear and raided the fridge for all the beers we had spare, then set off in the direction of Mosgiel, a town that is apparently well-known for its local legends and myths. The drive didn’t take too long, which is always good, but the next hour or so we spent trying to find the damn tunnel was a right challenge. To avoid a couple of nearby farms we headed into a patch of native woodland. This would most likely have been quite pleasant, if we’d been able to see where the fuck we were going. But, as we didn’t want to risk using the torches with the farms being so close, we ended up getting very lost among the trees and bushes.

After following a few false trails, we did eventually stumbled across the entrance to the tunnel. Just the faint sight of it in the distance raised our disheartened spirits. The next challenge, though, was to get past a locked gate. Fortunately, this wasn’t as bad as it had first appeared, probably due to the fact that we’ve had plenty of practice in the art of contortion over the years we’ve been exploring. To keep it brief, despite some initial doubts about our ability to contort through the space available to us, we managed to worm our way inside.

As expected, the inside of the tunnel was incredibly muddy. Even sticking close to the walls didn’t help very much. As for the tunnel itself, though, it was, aesthetically speaking, very pleasant. It reminded us of an old Victorian railway tunnel you’d find in the UK. The condition of some of the bricks in the Chain Hills Tunnel are quite poor too, which enhances its overall photogenicity. Other than that, however, there isn’t a lot else to see. That’s the nature of old railway tunnels unfortunately. We did find a couple of niches and a few pipes belonging to the sewer system, but they’re pretty standard finds in these places. Eventually, after what felt like a fair bit of walking, we found ourselves at the second gate. For some reason, the authorities had left this one open, probably due to the fact that the tunnel is inaccessible from this side. Whatever the reason, it gave us an easy exit from the tunnel, where we found ourselves on a narrow muddy trail surrounded by dense forest. Apparently, if you continue down the track for a while you eventually reach the present day railway line, but it’s quite difficult for anyone to access the tunnel from this side. We didn’t walk down the trail to find out if this is true mind, since we had a bottle of whisky to get started on back in Dunedin.

Explored with Nillskill.