Chain Hills Tunnel Open Day

Today we had a very special opportunity, a chance to walk through the usually-closed abandoned Chain Hills Tunnel which runs from Abbotsford through the Chain Hills to Wingatui. It is part of the same old railway line which included the well-hidden Caversham tunnel. The event was hosted by the Dunedin Tunnels Trail Trust as part of a fund-raising and awareness campaign with the eventual goal of having both tunnels re-opened to foot and cycle traffic.

Since today’s access was from the Wingatui end, Dad and I hitched a lift with KL of KL’s Self Discovery along the southern motorway to Mosgiel, and then around to park near the Wingatui race course. Already I’m getting a feel for how much distance this tunnel could shave from a similar journey, if one wished to do it by foot.

Once KL had organised her brood of three, we followed the rest of the 470-strong horde of gumbooted sight-seers up Gladstone Rd towards a private gravel drive leading uphill. We were greeted by members of the trust who pointed us in the right direction as we headed across the private section which they hope to raise the funds to purchase.

We passed the private home with miniature ponies and chooks in the yard before paying our koha and heading into the bushy cutting that leads to the tunnel entrance.

Normally each entrance to the 462m tunnel is locked and barred, but today the iron gates stood open and our only barrier was the thick sea of mud ahead of us. But we trudged through, flicked on our torches and stepped into the “darksome den”  – as one unhappy 1883 traveller described it.

Completed in 1875, this was the last part of the Clutha Line to be completed, and like many engineering projects of its time it was not without its difficulties and dangers. There was talk of it taking two more years than predicted due to the hardness of the stone encountered, with workmen labouring day and night in eight hour shifts in squalid conditions to get it done. Brick kilns were set up on site at each end of the tunnel to ensure no delays in obtaining construction material.

Six months before completion, a rock fall in the north end of the tunnel (which we were now passing through) claimed two lives and injured two other men. The deceased were Patrick Dempsey and Thomas Kerr, the latter of whom left behind a wife and seven children. Of the survivors, George Turnidge had both legs broken and was crippled for life, while a man by the name of Wedlock was comparatively lucky in escaping with only one leg broken.

Lucky for us, the tunnel is now completely stable, despite being abandoned in 1914 in favour of a new dual-lane one slightly to the south.

Hugging the walls in a futile attempt to avoid the worst of the mud, we almost stumbled over a heavy metal pump set into the ground. It turned out to be one of two vents in the tunnel for gas from the Wingatui and Mosgiel sewerage lines, but thankfully the DCC has capped them permanently in order to make the place safe for visitors.

We also discovered the two manholes, niches in the tunnel wall for workers to take shelter should they be surprised by an incoming train. Sadly, they did not save Irishman George Thompson in 1895 as he took a shortcut home late one night. It is possible that he had no idea they were even there, as they are very easy to miss in the dark. He left behind a large family, and provided yet another example of why it is important to treat working train lines with great respect.

After much shuffling through the darkness we finally burst out on the far side to find ourselves in a completely different world, enclosed on both sides by native bush and surrounded by fluttering fantails. Since this place is normally cut off from access, I expect they probably don’t get too many human visitors.

We were able to continue along the line of the old track a little way until we were stopped by warning tape. If we’d been able to continue, the route would eventually have met up with the current track. We turned back for our second trip through the dark, and this time we did spot something sheltering in the manhole.

We couldn’t identify the species as there are about 60 different types of these reclusive scavengers in New Zealand. However we are quite sure it was not happy to have its nice quiet home disturbed by hundreds of curious sight-seers.

The Dunedin Tunnels Trail Trust aims to create an 8.5km walking and cycling trail from Dunedin to Mosgiel which incorporates both this tunnel and the one at Caversham. It’s a brilliant idea, because as things stand it seems impossible (at least to me) to get from Dunedin to Mosgiel by any means other than gas-guzzling vehicle. Coming this way, travellers could experience a peaceful walk through history and native bush, far away from the dangerous roads.

The current barrier is the need to purchase the property at the north end of the tunnel in order to put in and easement before re-selling the remaining land. To do so, they must raise a total of $550,000 by mid-April and are pulling out all the stops to do so. This is where our koha will go, and there is also a Givealittle page for public donations as well as private loans being sought.

So if you’re interested in seeing this tunnel open to the public on a permanent basis, go forth and donate! Hopefully someday soon the old tunnel will once again become a valuable asset to our community – and I look forward to walking it again when the time comes!

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