The Discovery and Exploration of Ogof Ffynnon Ddu in 1946

During the Whitsun Holiday [of 1946] we visited the Swansea Valley once more.  The Gwyn was already the centre of the caving activity in the Swansea Valley and cavers were to enjoy the hospitality of Mr. and Mrs. David Price there for many years, although at that time the number of cavers was very small, usually not more than ten at the most.  In the forties and fifties the mining industry was still very active in South Wales and there were a number of collieries in the vicinity.  Amongst the miners who used to visit the Gwyn on a Saturday night were some very fine singers. One of the best was ‘Reecy’ Watkins who used to sing pieces from the operas and if he was in form he would sing The Holy City.  Some of the singers in the valleys of those days, with a bit of training, would have been the equal of any opera singer.  We discussed the possibilities of a cave on the east side of the valley, near the spring of Ffynnon Ddu, with the local miners and quarrymen but did not receive much encouragement for they maintained that the rock on that side of the valley was too broken up to support a cave.  This did not put us off because, to us, a considerable quantity of water entering the hill at Pwll Byfre and coming out at Ffynnon Ddu, indicated a considerable cave system.

Although we achieved nothing very much this holiday we did at least get to know the area.  We went walking on the mountains either side of the Swansea Valley: westwards above Dan yr Ogof to Waun Fignen Felen, the deep swallet draining the peat bog of that name, and further west again to Sink y Giedd, another large swallet.  These two swallets were assumed to be the main swallets supplying the water resurging at Dan-yr-Ogof.  There were numerous other smaller sinks with water disappearing into the ground.  On the other side of the valley, above the rising of Ffynnon Ddu, we walked past the limestone quarries near Penwyllt railway station, to the swallets of Pwll Byfre and Pant Mawr.  At Pwll Byfre the water which flows off Fan Gyhirych, through quite a large bog, sinks at the foot of a circular cliff in so many places that it is not a very hopeful place to start a dig.  From the same bog another stream starts, also called the Byfre, which flows down to the valley to join the River Tawe near the Gwyn Arms.

We had had a good chance to examine the possible places to dig into the cave [OFD].  Numerous likely spots were examined in the vicinity of the resurgence but wherever we tried to dig near the level of the River Tawe we found everything choked with glacial drift, and digging down any depth brought us near the water table.  Higher up there were holes in the rock but they were all such narrow cracks that there seemed little hope of entering a reasonably sized cave passage.

Ian Nixon had come over with several other members of the UBSS. There was camping behind the Gwyn and a small amount of room in the loft above the toilets.  The elite, Arthur Hill, Gwyn Tudor and some others stayed in the Gwyn.  The rest of us camped behind the Gwyn and did our cooking in the ladies’ toilet.  Serious drinking did not start much before about eight o'clock,  so the ladies would not be expected to need their toilet until at least nine o'clock.  One of the advantages of the ladies’ toilet was that it had a table for primus stoves and was on the opposite side of the Gwyn to Charles Freeman’s bees, which he housed behind the Gwyn.  They always sounded angry after Charles had spent the day tormenting them and stealing their honey, even though he said we imagined it.

Some of the local members, including Ken Leadbeater and Will Thomas, two colliers, had started an interesting dig on the Cribarth Mountain, which overlooks Craig y Nos Castle.  The Cribarth has never  attracted me as a viable place to dig although there are two places where water resurges in quite large quantities.  On the south side there is a spring which the water authority uses to supply Abercrave and on the north there is a rising with a small cave behind which is the local water supply to the farm and Craig y Nos Castle when it was a hospital.  All this water must come from somewhere and the top of the Cribarth does not seem a big enough area to collect it.  It may be that some of it comes from the lost valley to the north.  By the side of the mineral track on top of the mountain there was a slot down which a pebble would rattle for a hundred foot or so.  However, Ian and I spent most of our time in the vicinity of the spring at Ffynnon Ddu.

We started several small digs in and near to Pant Canol in the Penwyllt Valley, but nothing appeared to look very hopeful.  It was in one of these workings that I was trying to dislodge a small boulder lodged in a crack above my head.  This I managed to do with a crow-bar but I had removed my helmet because the place was so tight.  I managed to shift the boulder but it hit me on the head on its way down.  I spent the evening having my head dressed by the lady members of the club

Ian [Nixon] and I had a discussion with Bill Weaver to see if he had any ideas as to the best spot to start a dig into the cave behind the rising at Ffynnon Ddu.  Bill recollected that Cyril Powell had told him of a flood in the valley where there had been an outburst of flood water in the field at the bottom of the little valley known as Pant Canol behind the rising and that near the edge of the field was a small cliff face.  It was at the foot of this face he suggested we dig.  We had not considered this place before because the field did not belong to Cyril Powell, who was the owner of the land under which we expected to find the cave feeding Ffynnon Ddu, but to Jeffrey Morgan, one of the owners of Dan yr Ogof.  I wrote off immediately and asked Mr. Morgan if we could dig a hole in his field and he replied giving us permission to dig and to explore the cave on condition that Mr. Downey, his tenant, was also agreeable [see letter].  It was long after this that Sylvia Barrows, Mr. Powell’s step daughter, found the following among his effects:

A day in the History of the Hamlet of Glyntawe in the parish of Defynog in the year of our Lord - 1907 [Presumed to be written by Cyril Powell]

It was a Sunday in the mid-summer of 1907, over 55 years ago.  The morning started fine and very warm, but in the afternoon the black clouds started to gather portending a storm. The clouds banked up in thick, dark ominous layers over the Wern, Penwyllt and Fan Gyhirych and, as we subsequently learned, over most of North Breconshire.  Sometime in the afternoon the thunder started rolling and kept at it for some hours.  The rain came down over Penwyllt in torrents mixed with hailstones, some as large as acorns.  The same must have occurred over Waun Byfre and Fan Gyhirych and the Carmarthen Fans.  All this naturally oozed down into the Upper Tawe Valley.

Someone looking out of the windows of Craig y Nos Castle heard the sound of rushing waters and soon saw a red wall of water rolling down the [Tawe] river bed.  He had the presence of mind to telephone down the valley to Abercrave and Ystradgynlais to warn them of what was coming.  I understand that a lot of bathers were warned only just in time.  The fields of Rhongyr Uchaf and the lower hills of the Gelli were soon flooded to a depth of 7 feet. The cows of Rhongyr Uchaf, which were grazing quietly on the field, were caught in the flood, panicked and made for home on the other side of the Tawe, thus wading right into the middle of the big flood, and were carried away one after the other down the valley, some as far as Abercrave.

The flood in the Tawe blocked up the outlet of [the resurgence at] Ffynnon Ddu, to a large extent preventing the stream from emerging.  It was noticed by some of the people who lived in the Grithig at that time and who were quite alarmed by all the waters about them, that the water spouted out like a fountain at the point where subsequently Nixon and Harvey found a way into Ogof Ffynnon Ddu.                                                        back to the top

So it was during the first weekend in July [1946] that Ian and I arrived in the valley complete with some digging tools.  The day was one of those glorious summer days without a cloud in the sky and not a breath of wind.  It was one of the hottest days for years.  After arranging for accommodation at the Gwyn and calling on Mr. Downey, who raised no objection to our digging on his land, we started work.  At the foot of the little cliff there were some nettles growing on glacial drift.  I pulled these away, roots and all, and it was immediately obvious from the very strong cold draught coming up through the boulders that we were digging at an old entrance to a large cave system.  The draught was so strong that grass and dust were blown straight out of the excavation.  Every boulder we moved loosened grit which, instead of dropping down, was blown up into our eyes.  The temperature of the draught made it necessary to leave the dig every now and then to warm up in the sunshine.  Cave draughts are caused by a difference in air temperature; the temperature of the air inside the cave is at an all year average of 48°F [9°C] while that outside in summer is much higher.  The column of cold air inside the cave is heavier than the outside air and so tries to flow out of any hole at the lowest point near the resurgence.  In winter, the situation is reversed; the air inside the cave is still at 48°F but the outside air is now much colder and so the inside column is now lighter than that outside and therefore tries to flow out at the top of the mountain.  Thus it is useful in winter, when there is snow on the ground, to walk on the hills and see which depressions are melting the snow round them, indicating a stream of warm air from underground.  This situation can of course be modified if the barometric pressure is rising or falling at the same time.

We carried on digging for the rest of the morning in the glacial drift consisting of old red sandstone and gritstone boulders, but after we reached a depth of about 10ft it became obvious that we needed to shutter the sides of the hole to stop it falling in.  We had none of the necessary materials with us, so we gave up the dig for that weekend intending to return when timber and shuttering had been acquired.  We decided to try and arrange this in time for the coming August Bank Holiday weekend [which was then the first weekend in August].

After lunch, which Mr. Downey insisted on giving us, he showed us a depression further up the valley covered by some limestone slabs under which he thought there was a cave entrance.  We soon had the slabs out of the way, revealing a small hole.  We entered and explored a tight system of passages about two hundred feet in length, all the leads finally becoming too small to follow.  This has since been known as Downey’s Cave.  It was in 1954 that a connection was made with the main cave of Ogof Ffynnon Ddu.  Tony Knibbs writes in his diary on the 20th. September 1954:  

Malcolm Cotter and I joined forces with Noel Dilly in a survey of Downey’s Cave, about 120 yds North of the entrance of Ogof Ffynnon Ddu.  For about 200 ft the cave takes the form of small solutional tubes with very old formations.  After one bails out a nasty little pool in an equally nasty squeeze the cave opens out into a very fine bedding cave with a beautiful gour floor and some good stalagmites.  The lower end of this passage ends facing a dammed pool beyond which is an extremely tight squeeze in liquid mud leading into Ogof Ffynnon Ddu.  Noel and myself are the only ones to have made this link.

(It was some years later that Bruce Foster, a very small member of the SWCC, also managed to squeeze through into the main cave of Ogof Ffynnon Ddu via Downey’s Cave.)                                                        back to the top

Back in Bristol, we managed to scrape together some wood, including one pound’s worth of new wood allowed by the rationing system [still in force following World War II].  We arranged to get this transported to Wales in various people’s cars and by the bank holiday we were back at the dig complete with shuttering.  Progress was now much better.  The day was not quite as hot and the problem of dust being blown upwards into our eyes was not as bad, because there had been some rain the previous week.  Also, this problem receded further as the dig got deeper because the rubble we were pulling out was becoming damper.  About midday we were joined by Bill Weaver.  Our hole was now about 10ft. deep and the boulders in it seemed to be getting bigger.  The timbering was going well as the cliff face provided one solid wall for support.  At about 15ft deep a particularly hard gritstone boulder was holding us up.  It would not break up with a sledge-hammer and we had no explosives with us, so we tied a rope round it and the three of us managed to pull it out.  Underneath was a black space.  We were in!  We had a quick look inside and after seeing passage disappearing into the distance we returned to the Gwyn where we had a quick meal and collected the rest of our caving gear.

We were quickly back at the dig.  The party had now increased in size and consisted of Bill, myself and Ian.  We had also been joined by a girl called Joan and a caver from Yorkshire, whose name I never knew.  We all struggled into the small entrance; cave digs are notoriously only just big enough to get through.  After about 20ft of crawling we were able to stand up, and in another 30ft or so we were on the edge of a lake nearly 20ft. long and at least 6ft. deep.  Bill said it was traditional to top it up, so we did, that is all except Joan who was not blessed with the necessary external plumbing.  The depth of the lake put us off wading through and, with a bit of care, we found it was possible to traverse round on the sloping ledge on the left-hand side.  On a subsequent trip, Bill slid gracefully off this ledge into the lake and all that could be seen was his arm holding up his electric cell above the water.  Rounding a left-hand corner we came to a bedding plane section, sloping upwards, the floor of which was covered in white calcite.  This was quickly named the Great White Way.  The pristine beauty of this has all now been destroyed, some by the passage of many feet, but mainly because Cyril Powell lowered the level of the floor by about 3ft, in the days when he was trying to make the cave suitable for tourists.  It was during this work that the entrance lake was filled in with the rubble.  Mr. Powell also blasted a new entrance [which is the current entrance] on his side of the fence, entering the cave on the inside of the entrance crawl .

Beyond this point, the passage becomes bigger and, after passing a small passage on the left, we entered quite a large chamber some 30ft high, later named ‘The Cathedral’.  The way out was a climb of about 10ft over some calcite gour pools, with the passage continuing beyond.  Niphargus, a white sightless shrimp, could often be seen in these gours.  At about eight hundred feet or so from the entrance we could hear the dull boom of the underground river in the distance.  We were now expecting that we could be going all the way to Pwll Byfre.  We were still in large passage when we came to a parting of the ways with three possible ways on.  Forwards was over a deep pool, Pluto’s Bath.  To the left was up a climb with a series of gour pools at the top, which came to be known as the Toast Rack, and to the right in the floor was a low crawl leading to the river which must now be very close, judging by the noise it was making.  We chose this last option and after a section of crawling we stood up in a passage leading to a T-junction, where we found the stream rushing past in a black limestone passage.                                                        back to the top

We all started wading up the river, which was flowing over the full width of the passage, on average about 5 or 6ft wide and rarely less than 20ft high.  It seemed nothing could stop us before we reached Pwll Byfre, over a mile to the north-east.  Battling up against this river, which was fairly high at the time, was a new experience for all of us.  We were familiar with lakes and short cataracts such as in Dan yr Ogof, and the stream in Swildons Hole on Mendip was quite a small affair compared to this river bowling along between black limestone walls.  We struggled upstream for several hundred feet over the very uneven floor.  We had traversed across one deep pot and we were on the brink of a second pot.  This pot was wider than the first and there was no way of climbing round it.  It became apparent that the river could go on for miles.  It was getting late and we had explored much more cave than we had ever expected.  We therefore decided to return to daylight and complete the exploration of this fabulous river the next day.

On returning to the entrance, we were amazed to see the small field outside the cave crowded with people.  The news of our discovery had spread very quickly.  A large number of SWCC members were there including those who had spent the day exploring Llygad Llwchwr, a resurgence cave to the west near Carreg Cennen castle.  It seemed also that a large number were locals living in the Swansea Valley, including Edwin Morgan, the brother of Jeffrey.  I was a relative newcomer to the valley or I would have known more people.

That evening at the Gwyn Arms was one of considerable celebration.  The big question was how far the underground river could be followed the next day.  Pwll Byfre was over a mile away in a straight line; an underground river would twist and turn and it could be possibly twice this distance.  We did not dream that anything could happen to stop us traversing the whole length.

Next morning, despite having not had much sleep because of the excitement, anticipation, and perhaps the odd celebratory pint of beer, we were all up for an early breakfast and then over to the new cave.  Some time was spent adjusting the shuttering in the rather hurriedly excavated shaft and fixing a fence to keep out Mr. Downey's farm animals, and then everyone piled into the cave.  The diggers, Bill, Ian, and myself were joined by John Parkes and Rod Pierce and we made our way upstream from the place where we left-off the previous day.  After passing this second pothole, which turned out to be only waist-deep we soon came to a 3ft waterfall on a left-hand bend in the passage.  We carried on upstream past a section with a white calcite line down the middle, past two more deep potholes, until we came to a place where the water was emerging from the right-hand wall.  There was no possibility of following it as it was flowing uphill out of a sump.  The main passage, however, turned to the left and carried on.  After a couple of hundred feet it became much increased in height; whereas it was 20 to 30ft high it was now over 80ft high but there was now only a small trickle of water on the floor.  After another 1000ft or so in this passage, the place opened up into a large chamber blocked to the roof by a huge pile of boulders.  On examination, we found there was no way through.  This was named ‘Boulder Chamber’ and was to be the end of the cave for many years.  Our expectations of reaching the vicinity of Pwll Byfre were dashed.                                                        back to the top

On retracing our way back down towards the entrance, we were surprised to find the stream passage full of people.  These included Cyril Powell, Toots and Margaret (Mrs Bannister’s daughters, who lived at the cottage near the spring), other people who were not normally interested in caving, as well as the other members of the club.

Meanwhile, other parties had been exploring some of the side passages.  John Barrows had gone up the left hand passage near the entrance and found a chamber underneath it, which could be reached via two holes in the floor of the passage.  At one end of the chamber he found a human skeleton lying at the foot of a boulder choke.  Ted Mason who was working in Ogof yr Esgyrn, the bone cave above Dan yr Ogof, came over with his archaeological team to examine the bones.  Unfortunately there were no artifacts with the bones: no buttons, buckles or nails from shoes, so it has never been satisfactorily dated.  The boulder choke is very close to the surface and it is thought that this could have been an early explorer who was trapped by a boulder fall or it could have been a bronze age burial.  These bones now reside in a cardboard box somewhere in the National Museum in Cardiff.

John Barrows tells a tale of an itinerant castrator who entered the cave by the spring during an exceptional drought.  He took his bugle with him and the people at the entrance heard the sound of his bugle getting fainter and fainter as he penetrated the cave until it could no longer be heard.  Sadly, he did not return and was never seen again.  I do not believe that these bones are those of the castrator. For one thing the spring is completely blocked just inside the entrance and, in any case, if it was him there would have been a bugle by his side. The favourite explanation is that it is a bronze age burial.

Another party had found a passage after climbing a steep calcite slope, the roof of which was formed of strange pendants dissolved out of the solid rock.  Further on was a lake about 4ft deep in which stood a 20ft white calcite column, the finest formation yet found in the cave.  Squeezing through the constriction at the end of the lake, mostly full of water, another small chamber could be entered, in the left-hand side of which was a window overlooking the stream passage about 50 ft below.  Later it was found to be not too difficult, using a rope, to climb down to the river.  This was named The Eagle’s Nest.

That evening in the Gwyn Arms the club held a meeting which named the new cave Ogof y Ffynnon Ddu.  Over the years this has been reduced to Ogof Ffynnon Ddu or even OFD.

Unfortunately I had to return to work in Bristol on the Tuesday but Ian and some UBSS members were staying for the whole week.  During this week they managed to complete a survey of the cave as it was known then.  I was not very sorry to miss the surveying; standing in the river holding the end of a tape for hours on end was a pretty cold and miserable activity mainly due to the lack of ‘activity’.  From their figures I drew out the first survey of the cave.  This showed that only a short distance had been made towards the swallet at Pwll Byfre, about 2000ft at the most.                                                        back to the top

The exploration of Ogof Ffynnon Ddu proceeded slowly over the next few months.  On 17th August Paul Dolphin and Colin Low climbed up about 10ft on the right hand side of the main passage and entered a high rift passage, about 80ft. high to start with, gradually reducing to a crawl which eventually opened out into a boulder filled chamber (Low’s Passage).  There was a very nice bunch of helictites on the wall not far from the climb up.  Unfortunately, these have mostly been broken.  These became known as The Fingers.  I believe I am the only person to have taken photographs of these in their original unbroken state in both black and white and in colour.

Later, on 29th September, a party consisting of John and Anne Parkes and Bill Weaver with BEC members H. Stanbury and J. Bosworth climbed about 50ft. up a waterfall on the left of the main passage and entered an extensive series of passages now known as the Waterfall Series.  On their way back, John's wife Anne disturbed some boulders at the top of the climb and was lucky not to have been carried away with them as they crashed down the 50ft waterfall.

Soon after the discovery there was an attempt by the Cave Diving Group to dive through the sump at the head of the streamway.  The divers were Graham Balcombe, Don Coase and Bill Weaver.  The date was 16th November 1946 and, as this was Bill’s first underground dive, it was code-named Operation Alpha.  A large number of people had been assembled for carrying the enormous amount of equipment along 1500ft of streamway to the sump.  I remember that I carried a very large Nife battery in and out.  I don't think it was used in the end.  Other members of the SWCC carried in lead weights, bottles and everything else needed for the dive.  Although there was a convenient ledge near the sump it was not very wide and most of us had to stand in the cold water, getting perishingly wet and cold after the struggle up the stream, during the long wait while the divers dressed and disappeared into the sump until they eventually re-emerged.  Unfortunately the passage underwater changed shape and became too narrow to negotiate after about 40ft.  The divers were undressed and their equipment prepared for the long struggle down the stream out of the cave.  Graham was not too pleased when I dropped one of his log sheets into the water and it floated off in the fast-running stream towards the resurgence!  

This was the end of my interest in the Cave Diving Group.  Although I had been a member since it was formed, I had never taken to diving in caves as the equipment then in use did not seem very safe.  All the thanks the large party of helpers got was a mention in the report of the operation: “Our slaves acquitted themselves well”.  About a week after the event I received a bill from Graham for one shilling for the loss of a webbing belt.  This had been attached to his battery, which I had struggled up the stream with.  So I sent him a postcard with “You can stuff your bill up nuncs’s parachute”.  I didn't know what it meant but it sounded good at the time.  I assume it was put down to “bad debts” as I never heard any more; neither was I asked to help again.

With this operation, the main exploration of Ogof Ffynnon Ddu (I) was nearly complete.  We were stopped by the Boulder choke, and the sump had proved to be impenetrable.  It was going to be nearly 20 years before a way was to be found into the miles of cave between Boulder Chamber and Pwll Byfre.

Edited by Jem Rowland,                                                        back to the top
March 2009