The Black Mountains

3 Responses to “Cefn Glas tunnel revisited!”

1. 1 Malcolm Barr
   May 5, 2009 at 11:49 am

   The Pontygwaith bridge is quite an interesting shape; aint nothing like that here in NZ. It’s a pity that the Cefn Glas tunnel is falling to bits, but it’s good that you’re documenting it so there’ll be some record of it in years to come. Keep up the good work.

2. 2 Dave Workman
   October 13, 2010 at 9:49 pm

   Dave Workman
   October 13, 2010 at 9:28 pm

   And yet ANOTHER ‘adventure’ to ANOTHER disused railway tunnel (Cynon Valley) for the second time recently and now on Sunday – 10th of October 2010.

   I refer of course to the Cefn Glas Railway Tunnel (disused) since the mid 1960s. On the first visit to this site (a few days before), it literally took an ‘age’ to discover it’s location, due mainly to the overgrown fauna and flora around and about the portal (which is not too far from the Lletty Turner lay-by). On discovering it (the first time) my friend (Phil) and I had gone very ill-prepared, so returned home and set ready for another visit to this site (10/10/10) – suitably prepared this time.

   It must have been nigh on 1.30pm this day, in bright sunshine that we now both made our way to the tunnel’s portal (through ankle deep muddied water, where rubber wellingtons are a MUST). I noticed that at the entrance (Cynon Valley side) one cannot see the distant light of the exit into the Merthyr Valley at all, but simply a few steps inside the entrance and light was clearly visible the other end. (I would advise anyone exploring this disused tunnel to wear wellington boots, safety helmet and take a good torch) even though the ‘light’ from the Merthyr side gives reasonably good effect. I witnessed NO danger of stones or the like cascading from the roof of the tunnel, but nevertheless I would advise safety head gear, if nothing more than to prevent your head from getting soaked by the numerous streams which have over time found their ‘lowest point’ and are running through the sides and roof of this tunnel.

   I noticed that whilst walking through the Cefn Glas Tunnel that it seemed as if we were walking a slight incline (this could have been a ‘trick of the light’ but it certainly seemed as if we were walking slightly uphill).

   I was amazed to discover the items we came across inside this tunnel (large parts of a car – no doubt having been driven through the tunnel at some point, as well as three large toilet cisterns) which made me ask – “Why on earth would anyone want to drag such heavy objects half way into a tunnel in the first place?”

   Another reason for the need of a good torch, is that when you are approaching the Merthyr side of this tunnel, there are sections of the middle of the ground that can be quite treacherous if you come upon them unseen. I think these (at one time) may have been drainage holes, because there are about four or five (which are full of flowing water) and about 18″ to 24″ in depth. These features are spaced about 40 or 50 feet away from each other and are where the middle of the track WOULD have been. They are surrounded by concrete sides and each one is about a yard by 18″ in size. We actually discovered that its FAR safer to walk (on route to Merthyr) on the right-hand side of the tunnel, and the same side on our way back. The left hand side (on way to Merthyr) has over the years been subjected to many roof falls, whereby there are large areas of fallen masonry which if unprepared for this, could be a hazard.

   The odd thing we noticed that at the exit of this tunnel (Merthyr side) – one could still see the light emitting from the Cynon side), whereas as this ‘light’ was not visible from the entrance at Lletty Turner (Cynon side). Also (need for wellington boots) there is a large area of muddied water on the Merthyr side (as my friend discovered to his cost) – this water which consists of thick mud seems to be running along the cutting right up to the point where the cutting is blocked off with the A470 road running above it. This MUD is in fact quite deep (as my friend found out) – where I ascended the steep slope at the tunnel’s exit, and whilst it was a hard climb, it was worth it if only to see the view behind me of the mountainside.

   We did notice something rather strange inside this tunnel, which I feel important enough to mention. We came across a large hole in the side of the tunnel (left side from Cynon), which had seemed to have (in some past time) been ‘worked’ by someone, as there was a level above it (inside this hole) which planed off to a dead end, and another DEEP hole going down below the level of this tunnel (needless to say we did not explore this further), but it would be interesting to discover why, and what this was. (We thought perhaps some form of mining activity, perhaps excavated during the year long Miner’s strike of 1984/85???)

   We did notice however, that considering this tunnel hasn’t been used for nigh on 45 years, the surface of walking area was quite free of large falls of rock and bricks, and do not present much of a problem on the feet.

   We are awaiting the development of photographs which we both took inside and around this tunnel and once developed we shall be pleased to publish them on this site.

   Finally, as for Paul.s comments relating to the Aberdare-Merthyr Tunnel (near Cwmbach), I was at this site only a few months ago, and for CERTAIN there IS access to the Cwmbach side of the tunnel, but am presently unsure of any access on the Merthyr side. Again, I would suggest STRONGLY to anyone wishing to explore these old disused railway tunnels, to make sure that they go WELL PREPARED (Good strong torch, plus spare batteries, safety helmet and steel-capped wellington boots)

3. 3 twomint1
   October 17, 2010 at 2:32 pm

   An early 7am (Sunday, 17th October) start for a visit to Cefn Glas tunnel, approaching from the eastern (Edwardsville) portal side. As I live quite close to the tunnel, we (the dog and I !), walked from Merthyr Vale towards Edwardsville and then turned right down to Pontygwaith bridge – the turnoff is beside a bus stop and a sign for Tea’s at Pontygwaith Farm). This might be an option for visitors coming by car as there is a limited amount of parking at the bottom of this road just before the bridge which is used by fishermen fishing the Taff. From here, it is about 10 mins walk to the eastern portal.

   The weather was fine, cold and wet from dew but drying out as the sun began to rise. Following the path over the bridge, under the A470 underpass, and up the other side, you arrive at a road. As Sparhawk has said, don’t go straight on (up the mountain) or right (towards Aberfan). Go left on what appears to be a dirt road. There appears to be some sort of work being undertaken by Welsh Water along the track and after about 150 yards you will see blue barricades closing off the road but there is a path around this on the right hand side. (Closer inspection of the ‘works’ inside the barricades show an excavation down to a big water pipe). You then come to a gate erected by the local farmer to keep his sheep in. Once inside the outline of ruined buildings and the canal bridge are visable. I’m never sure if these old buildings are from Cefn Glas mine or from Buarth Glas Terrace which was cleared to build the A470 – http://www.alangeorge.co.uk/pontygwaith.htm

   Walking on, you will come to more blue work barriers and on your right, two elecricity sub station boxes. You are now standing on the tunnel. To your left you will make out the tree lined cutting going towards the A470. The best approach to the eatern portal is to walk towards the pylon and then cut left through the plantlife which brings you onto the southern embankment. As mentioned by Sparhawk again, it is slippy on the way down but once down you can use the fallen tree (still there !) and the fallen facade stones to gain fairly dry access to the tunnel. But on first seeing the facade, it is with a hint of sadness to see the current state of broken and fallen stones considering the work that went into its creation. A lot of the water at the portal enterance by the way, seems to be coming from a stream of some sort coming from the northern (Aberfan) side and can clearly be seen flowing down the side wall. Something to do with the Welsh Water work maybe ?

   On entering the portal, light from the western portal can clearly be seen at the end. At this stage, the dog (Welsh corgi) who seems to revel in tunnels and dark places, took off at a rate of knots towards Abercynon ! I would echo what Dave Workman said at this stage – wellingtons or good boots, a good torch and head gear of some sort as the first 100 yards or so were very wet from overhead water this morning. Also, walk on the left hand side as Dave mentioned towards Abercynon as this is the ‘cleaner’ side.

   The tunnel, overall, once inside and keeping to the left hand side, is in a fairly decent state of repair, all things considered. Since my last walk through about 4 years ago, not a lot seems to have changed. The drainage holes seem to have grown slightly and the fallen stone / roof lining on the right hand side does not seem to have grown from what I remember. About 3/4 of the way through to Aercynon, I finally came upon the dog (always pretty much in sight or at least his eyes shining in the torchligh were) who had decided to stop at the aforementioned toilet equipment !

   Once out at the western portal, we didn’t explore too much save for stopping for a quick cigarette. As it was still early (8.30am ish), it was still quiet. Keeping to the right hand side for the return we returned out at the eastern portal just before 9am. We returned back the way we came but instead on going via the main road after Pontygwaith, we cut left and returned home via the ‘Tram Road’ where the original flags from Trevethicks line can still be seen (Tram Road runs parallel with the current Merthyr – Cardiff line).

   A few historical notes. I am not from the area but my wife is and she used to travel through the tunnel in the 70’s. Back then they were convinced it was haunted but none the less still went through. She dosen’t think, or can’t remember a bridge over to the tunnel from the Edwardsville side that is still there. They used to get to the tunnel by walking from Quakers Yard (back road, starts by turning left over bridge by QY Grammer School) to Abercynon. When the road turns left at the T junction at the top (just after crossing bridge over A470), you instead go right, which is driveable. This road goes to Aberfan but is gated after about 2 miles denying access to vehicles. There is plenty of parking along here and is another option for parking as the eastern portal is less than 5 mins away.

   What there is on the Taff Trail / Tram Road in Edwardsville is a big pipe and walkway crossing the Taff (remnents of one of the viaducts is right beside the pipe). Access to the pipe is resricted – a wall and mesh – but this can easily be overcome. I suspect that on the other side there is an underpass to the old railway cutting / Circus Maximus under the A470. BUT, I also suspect that this is locked as a lot of the underpasses under the A470 are in this area. I will investigate the Circus Maximus more to confirm this. Also the new train lines are on the Edwardsville side of the Taff and do not need to be crossed.

   Finally, the mine workings oservered by Dave do indeed date to the Miners Srike. Both Deep Navigation and Merthyr Vale pits are close to the Cefn Glas tunnel and as the strike went on, the tunnel was deemed a good way of getting access to the old seams from Cefn Glas colliery. I’m not sure how much coal was extracted from the tunnel during the strike but that is the history behind it (the wife for example is adament the working was not there in the 70’s).

   Hope this has helped !