Abernant Tunnel (Merthyr Tunnel) at The Black Mountains

I recently discovered that I’m fascinated by old industrial relics, and abandoned train tunnels hold an extra-special interest for me. I was delighted, therefore, to discover that one of the longest in Wales is right on my doorstep, by Merthyr Tydfil, a stones throw from where my Girlfriend and I often park for lunch!

Background

The Abernant tunnel is the one in question, (also known as the Merthyr tunnel, or Aberdare tunnel) and it’s one of a large number that perforate the south Wales hills and mountains, relics from an age of industry and expansion. Nowadays, the only way out of Merthyr Tydfil by train is south, following the valley past Pontypridd and on to Cardiff. But back in the day, when the coal industry was thriving and GWR (Great Western Railways) were a hugely influential force in the land, there were several routes away from Merthyr by train; to the north a tunnel at Morlais would see you to Brecon (incidentally, this tunnel is still there and visitable), to the east a series of curious loops and switchbacks saw trains running to Abergavenny and Ystrad Mynach, and to the west, trains ran through Mynydd Gethin towards Aberdare, and eventually all the way to Neath. The tunnel through Mynydd Gethin is the Abernant tunnel, and is 2497 yards long (around a mile and a half). The tunnel was single-track and ran specifically from Abercanaid through to Cwmbach in the west. Construction was slow and costly as no airshafts were possible (this tunnel is 660 feet deep at its deepest point).

Built in 1853, and bricked up in 1967, this tunnel must have seen a huge amount of traffic as it linked one of the most prolific coal mining centers in Wales with coastal steelworks and docks. It’s sad to see such civil engineering works, which once people must have taken great pride in building, abandoned and forgotten. One good thing is British rails decision to remove the brick wall at the eastern end and replace it with a flimsy fence…

Visiting the tunnel

Both portals are quite close to parking spots. For the eastern portal, park at the well-signposted picnic spot in Gethin forest, and follow the footpath, Coed Morgannwg Way, north past the farm. After about 3/4 mile of winding paths (quite rocky and they go up and down steeply) a small rusty bridge is reached. I believe this to be the Upper Glyncanaid bridge, and it crosses the disused rail cutting just east of the eastern portal. If you look to the left, you’ll probably see the tunnel lurking in its cutting, not far away. The route to the western portal is shorter and less rugged, and also flat. Find a place to park near the top of Blaennantygroes Road in Cwmbach, Aberdare. Just before the road turns into a private driveway, a footpath leaves the left hand side of the road, running between fields and over a tumbling stream. You’ll pass a crumbling bricked embankment to your right, before the path joins another, larger one. This is the route of the old train tracks, and if you turn right and double back on yourself, after a short distance the Eastern portal will be looming in front of you.

UPDATE 14/12/2008

We decided to finally go the full length of the tunnel today, and to our dismay the eastern portal has been blocked up, with chipboard and a wire fence. Of course we tried the western portal (in Gethin Forest) and this is still accessible, the same as before.

Description

Abernant tunnel is 2497 yards long, and that’s a long way in the dark. It is only slightly S-shaped, but enough to mean that both portals are not visible from the centre mile of the tunnel. If you decide to visit, make sure you’re well equipped with warm clothes, good shoes, and plenty of torches and spare batteries. Definitely don’t go alone… we didn’t see any ghosts or monsters, but if you do get into difficulty, a mobile phone won’t work under 600ft of rock. The eastern end of the tunnel is single track from the word go, and it is in very good condition, with recesses every 30 metres or so. The western way in is more interesting… The tunnel is very wide to begin with, and there are small ruined buildings not very far in, with fireplaces. After these, the tunnel abruptly become single track. Again, this end is in very good condition. Interestingly, the tunnel has short sections that are wider, and much higher than the rest of it. These enlarged sections do not appear to serve any purpose… could they have been required due to changing geology? In some of the recesses, coal seams are visible, and some of these appear to have been mined a little!

Map

Map of the area. Thanks to Google earth for the roads

Photos

The eastern portal is a little foreboding.
It says: “Come in, all welcome!”
The cutting towards Merthyr Tydfil
Looking out of the east portal
4 Explorers
Who you gonna call?
I’m not spooked…
Western portal
The western-most end, double track
Pointless barbed wire
Into the dark

New Photos from the June visit

Axeman and I decided to revisit the tunnel this June, so he could finally walked the entire length of it. This time I took some detailled shots of the buildings inside the tunnel and we also brought the green laser and my new super-bright torch along for some creative shots which came out really well. Worth noting that the western end is now well and truly closed up. A large metal gate has replaced the chip board, but the eastern end is open as usual.