Digs Around Ystradfellte

Theoretical Pot (9162 1476)

The dig is situated through the tight squeeze at the base of the 30 feet pitch. It is obvious that this dig has been worked by persons unknown in the past. Digging this time around involved removing spoil from a tight, steeply dipping tube, carrying a small stream. After a few digging sessions it became clear that the tube degenerated into a very low bedding plane, approximately three inches high. Work continues to enlarge this using chemical means of persuasion. Many thanks must go to Malcolm Stewart for constructing a spoil retaining structure, without which the dig would not have proceeded, and for hiring a Bosch drill.

Ogof Cagoule (9120 1208)

This site is situated on the east bank of the Afon Nedd Fechan some 30m upstream of the Pwll Du resurgence for the Little Neath River Cave system. In the hope that this site may represent an abandoned rising for the Little Neath River Cave system the entrance has been substantially enlarged from a flat out crawl to allow easy removal of spoil. The cave ends in a substantial stal blockage where only slow progress can be made tediously chipping it away. A draught noticed to be disappearing up a choked aven to the left of the stal blockage probably arises from a small cave Ogof Cagoule II directly above the main cave. Many thanks to Chris Crowley, Andy Todd and Charlie Peacock for their work here.

Pwll-Y-Phaiadar (Pool Swallet) (9364 1190)

This is a large collapse feature surrounded by dense forestry which takes a stream from the south-east and another from the north. There appears to be some confusion in the destination of the water. Ockenden (1991) indicates that it is likely to be the Hepste Valley while R and J Peat (1989) indicate that the water from Pool Swallet probably feeds the Ogof Ffynnon inlet extension. Obviously an accurate survey of the Ogof Ffynnon inlet and a spare tracing exercise would go a long way to solving this problem.

Due to the apparent significance of Pool Swallet, I decided to start a dig here. Rapid progress was quickly made until it beacame clear that shoring and regular access to means of chemical persuasion were required. The dig, however, was not abandoned before a distant draught was noted issuing from a fissure in the bottom of the dig. This is rather surprising considering that the dig is entirely in grit.

By the way, if anyone feels like a serious dig, I wouldn't bother going in Summer, unless you want to be "done to death" by the midges and flies that infest the pool.

Church Sink (Main Mellte Sink)

This sight has been extended somewhat since a 10ft shaft was sunk - see diagram A - to reach a mud-choked phreatic tube with a draughting airspace in 1990. In the summer of 1991 this phreatic tube was dug for approximately 30ft by myself to break into a small chamber approximately 15ft long by 5ft wide by 4ft high. A steep silt ramp led down on the right hand side of this chamber. At the base of this ramp a small percentage of the total water sinking at Church Sink that day was seen issuing from an impenetrable bedding. Downstream, a tight bedding approximately eight inches high was pushed by Malcolm Stewart for approximately 15ft with the sound of cascading water ahead. A draughting choke was also noted at the back of the chamber.

Unearthing an article in Pelobates 30 detailing the explorations of Church Sink by Frank Thompson, I immediately noted the similarity in the position and orientation of the chamber discovered in 1976 and that entered last Summer - see sketch plan B. Obviously further exploration will determine whether this is one and the same chamber. However, in the meantime maybe the original explorers might be able to help?

Ogof Igam Ogam

Two areas have received attention:

Sump 4

Work in 1991 centred on attempting to construct a dam which actually worked. Three separate attempts were made in 1991, and all failed. This was simply due to the fact that the bags were laid down on a silt floor and when bailing started the water undercut the dam. A possible solution for the future would be to construct a polythene pool structure into which the water could be bailed. Whatever is done, I don't feel Sump 4 should be abandoned as I believe this site still offers the best chance of entering the Pant Mawr Master System.

Bad Debt Passage

A very tight vertical squeeze at the end of the Snorer's Annexe bedding plane and a further squeeze under some boulders brings the caver out into a comfortable phreatic tube. The vertical squeeze gained instant notoriety among Croydon members in the Summer of 1991 when one of the more rotund members of the party was unable to extricate himself through the vertical squeeze and a mini-rescue occured. Back at the beginning of the phreatic tube it is at this point that the small stream which flows along the Snorer's Annexe disappears under the left-hand wall and is not seen again. The crawl, however, continues for approximately 30ft to where the passage becomes nearly choked with silt. A dig was started here in 1991 but was abandoned after only 20ft when the passage reached a complete aqueous mud choke.

In conclusion Bad Debt is approximately 50ft long with a 170 degree North-South trend. Most interestingly at the end of Bad Debt Passage the cave is well into the eastern side of the Afon Nedd Fechan gorge and has thus crossed underneath the river.

'Dry Way' Dig (9102 1330)

This one-time dig which can now be classified as a cave is situated in the western wall of the Afon Nedd Fechan gorge some 100m downstream of Ogof Igam Ogam (OIO) and a few metres upstream of where a large dry valley cuts the side of the gorge to reach the river.

The cave consists of 30ft of tight phreatic tube to a one time very tight downward squeeze. The squeeze was later substantially enlarged by Clive Jones (SWCC) to reach a small chamber among boulders in 1990.

The cave is interesting in that its end is very close to the highest point reached in the Snorer's Annexe boulder choke of OIO and that it only draughts when the entrance sumps of OIO are open. Also when the Afon Nedd Fechan is in flood, water has been sinking into this cave, presumably to enter OIO.

In conclusion this cave may provide a way of by-passing OIO's first three sumps, but shoring in the end chamber will be required in order to progress.

Crowbar Hole (9010 1464)

This site on Pant Mawr some 50m south-west of the Ogof Cul 5A entrance was opened up when it was noticed pebbles thrown down a hole in the bottom of a small shake hole fell for a reasonable distance. A 25ft ladder climb amongst some poised boulders led to a boulder ramp and a breakdown chamber with abundant "hanging death". A rift which would require explosives led down from one side of the chamber. However it was decided that this would be very unwise considering the decidedly unstable nature of the roof. The entrance pitch has now collapsed.

Adrian Paniwnyk