Sinc y Giedd

[tomfoord]

I was having a bit of a wonder around the DYO catchment area the other day, and couldn't help noticing that most of the water in the Afon Giedd goes underground a long long way (as in half a mile!) back upstream from Sinc y Giedd itself. Adjacent to the stream sink is a deep shakehole with the sound of rushing water in the bottom of it. It has been dug at some point in the past and has the beginnings of a scaffolded shaft in the bottom. However it all looks very horrible and unstable and the whole shakehole is in a bit of a state of collapse.
Does anyone know anything about this dig? Who's project is it? Why has it been abandoned? (Or has it?)
Don't worry, I'm not out to pirate it, just very interested in the area and hadn't heard or read anything about this sink before. It must have great potential!

Incidentally, best of luck to the lads I bumped into digging at Sinc y Giedd!

 

[rsch]

Adjacent to the stream sink is a deep shakehole with the sound of rushing water in the bottom of it. It has been dug at some point in the past and has the beginnings of a scaffolded shaft in the bottom. However it all looks very horrible and unstable and the whole shakehole is in a bit of a state of collapse.
Does anyone know anything about this dig? Who's project is it? Why has it been abandoned? (Or has it?)

It's called Pwll Dewi Sant, and from recollection it opened up naturally in the early 1990s. Abandoned due to lack of real prospect of progress in the bottom. The amount of 'sound of rushing water' might give you a clue as to why that is.

 

[NigR]

Tom,

Pwll Dewi Sant was originally discovered, explored and named by John Parker, Jeff Hill and friends - the stake belays at the top date from this period. The shaft, around 80 feet deep, was then descended by members of South Wales Caving Club who confirmed the assessment of the discoverers - i.e. that there was no obvious easy way on without extensive digging. The scaffolding, now in a dangerous condition, was installed at a later date by SWCC but no further progress was made at the bottom. As you point out, there has been a fair amount of recent movement around the sides of the shakehole and great care would be required if digging operations were to be resumed. The top of the shaft would have to be extensively scaffolded and spoil would need to be brought all the way to the surface. Anyone at the base of the shaft would be under a constant waterfall. Having said all that, prospects are particularly good from a geological point of view as it is in the main cave-bearing beds whereas Sinc y Giedd is not. Feel free to pirate it if you so desire!

Cheers,
Nig 

 

[Tony_B]

I can add to this, having been in there in the last couple of years. The site was re-opened by Martin Groves and others a few years back (this being the recent SWCC scaffolding that Nig refers to). However, the 80ft shaft originally explored has never been regained, and the entrance gives access to a much shorter pitch that reaches the stream you heard. This stream sinks almost immediately into a gravel sump that beat those involved in reopening the cave and looks pretty hopeless to me. It's a very interesting bit of cave, but three of us spent a considerable time in there poking around and didn't find anything worth pursuing (and we're all pretty determined Black Mountain diggers). Well worth a look (you'll need a ladder) but do bear in mind the unstable nature of the sides of the shakehole; we had to dig our way in and it slumps frequently. And no-one will be upset if you do decide to restart work here.

 

[tomfoord]

Thank you all for the info... Interesting stuff!

It looks like the entrance must have slumped and been blocked in the last couple of years then, as there's definitely no way in at the moment! (hence why I said the beginnings of a scaffolded shaft... it only goes down a metre or so before hitting a mud floor!!!)

Just wondering... if water has been a problem in the past, had anyone considered diverting the stream past the sink?

I don't think I'll be getting involved though... looks like far too much of a death trap for a wimp like me! Give me horizontal sand fill and a solid roof any day!

 

[NigR]

Give me horizontal sand fill and a solid roof any day!

Got just the place for you then, Tom! How does a 3 feet diameter phreatic tube with 6 inches airspace for as far as you can see sound? Nice solid roof with no loose boulders in sight. Easy mud/sand digging, 15 minutes into the cave, entrance 5 minutes from the car. Have even got permission from the landowner! Going there tomorrow (Tuesday) evening and am hoping to continue on a fairly regular basis throughout the winter. Let me know if you fancy coming along.

 

[tomfoord]

PM'd you Nig.

 

[NigR]

Have PM'd you back, Tom.