The Rediscovery Of Cwm Dwr II

by G. Campion

Cwm Dwr Quarry (new) Cave was first discovered by quarrying in 1938 and, after two brief weeks of exploration, was supposedly destroyed and consigned to the list of “lost” caves of Britain. Fifty-three years later, on 7th February 1991,1 was fortunate to be staying at the South Wales Caving Club headquarters in Penwylt, when interest was expressed in exploring a spoil-filled rift in the floor of the abandoned Cwm Dwr Quarry and some 200 feet from the main Cwm Dwr cave entrance.

In the company of two members from the South Wales Caving Club and three members of the Wolverhampton Caving Club, the removal of loose material from a deepening cylindrical shaft took place throughout Saturday and Sunday morning. Use of theSWCC dumper-truck made the removal of spoil and the haulage of boulders less laborious. As we dug, we had no idea of what lay below and knew nothing of the 1938 discovery. As far as we were concerned, we were into something completely new. Over 14 feet down and much to Adrian Doney’s surprise, an uninspired push of a spade caused one side of the shaft to collapse, revealing an arch with darkness beckoning beyond.

Like desperate pirates digging for booty, we almost shoved Adrian to one side, as we clambered to widen the opening and crawl through it. Soon we were all through into a passage, pleased that our efforts had been rewarded so quickly. The passage contained a small stream and was reminiscent of Ogof Ffyon Ddu. Small formations and calcite walls abounded. There appeared to be a number of ways on, but the possibilities quickly came to nought and the small stream disappeared into a bedding-plane, which was impossibly low. There was agreement that the stream had digging possibilities but, first, the find must be surveyed.

Back at Penwylt cottage there was much excitement, especially as the discovery was on the doorstep of the SWCC headquarters. Desperate searching in the club library revealed a 1938 article entitled “A Report of Exploration of Survey on Cwm Dwr Quarry (new) Cave”. Our survey taken that day and the 1938 survey seemed uncannily similar. Quarrying had clearly removed the upper section of the old discovery with the quarry floor being 30 feet lower than 53 years earlier. It was with mixed feelings that we took in the news, a little saddened that our find was by no means original.

The library report in the 1938 edition of British Caving by P. Rayner read:

During the Ogof-yr-Esgyrn “Bone Caves” meet of August, Arthur Hill and Bill Doyle reported that, in the company of Mr Ernest Roberts (YRC) and others, they had made an inspection of a 20-feet deep rift half-way up the working face of the Northern Cwm Dwr quarry, above Craig-y-Nos Station, which had been broken into during quarrying operations. Owing to the fact that the floor, of loose boulders, appeared to be afalse one and liable to run in, Mr Roberts decided that it was dangerous to work there and exploration was abandoned.

During the following weeks, it would seem that P. Rayner and friends, in the absence of Ernest Roberts, decided to return and try to get through. They discovered what we were to rediscover some 50 years later.

Like Rayner and friends, we returned the following weekend and began moving silt from the far end of the low stream passage. Conditions were uncomfortably wet with water constantly backing up to hinder our efforts. Such was the nature of the passage that a nasty duck was soon created with little prospect of the passage opening up beyond.

Dye testing has since shown that the stream flows into the Cwm Dwr Quarry (main) cave at the “rising” area. It is almost certain that the water comprises the same stream which was discovered by the “Ogof Scope” experiment in 1984, when members of the SWCC mounted a camera on a length of pipe with springs and triggers attached and lowered it down an existing 40-feet borehole, drilled by the Cym Dwr Quarrying Company ten years earlier. The hole was draughting and water could be clearly heard at the bottom. This somewhat eccentric but ingenious experiment revealed relatively clear photographs of a yet-to-be-discovered passage. To introduce scale into the exploration, table-tennis balls were dropped down the hole and photographed in their new surroundings. “Blob Hall”, as it was aptly named, is almost certainly a downstream section of the rediscovery beyond the duck. The photographs would suggest that the passage is quite large and leads tantalisingly on.

There is still work to be done and scope for substantial finds in the direction of Ogof Ffyon Ddu, but the duck and beyond will need to be enlarged by explosives.

When Ernest Roberts visited the area in 1938, the caves of South Wales had hardly begun to reveal their true potential. It was not until 1946 that Ogof Ffyon Ddu was first entered and 1966 before divers entered Ogof Ffyon Ddu II to break into a new system, which was to be the longest in the country. Cwm Dwr II will no doubt become just another ramification of the giant and sprawling OFD system, butthe elation of its rediscovery will always remain one of those “special” memories for those involved that weekend.