CAMBRIAN CAVING COUNCIL

Proposal to Dwr Cymru Welsh Water plc for access into the Ogof Carno cave system

Management Summary

The Ogof Carno cave system was found by cavers exploring an abandoned tunnel which was intended to enlarge the water supply for Ebbw Vale steel works in the early 1900s. The tunnel later passed into Dwr Cymru Welsh Water ownership. A number of natural passages leading off the tunnel have been expanded and explored by cavers since 1982, though progress has been intermittent due to diversions of interest into other nearby cave discoveries. Access had to be withdrawn in 2013 due to the major A465 roadworks and there were also health & safety concerns. Cambrian Caving Council would now like to negotiate a new access agreement for the Ogof Carno cave. We think this is a fitting project under the Welsh Government’s Year of Adventure 2016 initiative which promotes physical activity and healthy lifestyles, while the H&S aspects can be managed successfully with appropriate methods and precautions.

History

In 1905 the expanding steelworks at Ebbw Vale needed water in ever larger quantities. So Ebbw Vale Urban District Council began to drive a tunnel, starting in Cwm Carno and heading through Mynydd , in order to capture a large spring in Cwm Claisfer about three miles away without pumping. But tunneling contractors met with geological problems and their efforts were halted two miles underground in 1912 following an unfavourable survey by a geological consultant.

The adit (tunnel) began in boulder clay and some coal measures for the first 200m, but then entered hard millstone grit for the next kilometre before continuing through the Dowlais limestone. The tunnel rises gradually by eight metres over its considerable length, and it is a dead straight line for the first 2kms in which the entrance can always be seen as a pin-prick of light in the distance. The geological problems arose when the tunnel reached a band of weak shale which caused the roof to collapse repeatedly. However, the roof was shored up, as in coal mines, and good hard limestone was found again beyond the shale. Simply to give up after conquering the physical difficulty points more to financial and timescale issues than to geotechnical concerns.

The only current use of the tunnel is to make occasional discharges from the Carno and Llangynidr reservoirs via an underground pipe which emerges into the first 100m of the adit. The entrance to the adit was moved and re-engineered during the widening of the A465 to dual carriageway standard in 2013. The discharge pipe used to emerge around 50 metres into the old tunnel at a dam about one metre high which kept the tunnel beyond it completely dry. This pipe is now perhaps 100m inside the augmented adit. Caving, or exploring for new caves, through the old adit entrance was permitted by Dwr Cymru Welsh Water (DCWW) from 1982 to 2013 via an authorised access scheme run by Brynmawr Caving Club (BCC) who managed the key loans. The letters sent between DCWW and Cambrian Caving Council (CCC) along with minutes of a round-table meeting between DCWW and BCC are attached in the appendix to this proposal document.

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Fig. 1. Adit (grilled) with service road under dualled A465 road in 2014

Fig. 2. Cavers using the old adit entrance in 2010

Fig. 3. Signing-in book at start of the brick-lined dry tunnel in 2010

- 2 - Hydrology

An extensive research study was carried out by Bill Gascoine, a member of BCC, in partnership with DCWW who bought the water-tracing materials that he used. Sadly, Bill died in 2013 but his research is written up in the chapter he contributed to "Limestones and Caves of " edited by Trevor Ford, 1991, Cambridge University Press, ISBN 0-521-32438-6, pages 40-55. Bill worked as a chemistry lecturer at Ebbw Vale College. He utilised an unusual method to trace multiple sinks simultaneously using inert lycopodium spores dyed in various colours. These spores are not native to the UK and therefore unusual to find. They can travel through underground watercourses to become trapped in plankton nets placed across the resurgences of interest. The nets are then examined by microscope for the characteristic spore shape and the specific dye colours used. Only a handful of coloured spores emerging provides a certain hydrological result. Thus the water flows within a wide area were easily revealed without compromising the public water supply.

This is important because the land immediately to the west of Chartist Cave (see map below) drains to the Ffynnon Shon Sheffrey resurgence between and Shon Sheffrey’s Reservoir. Water sinking at Chartist Cave and Ogof Cynnes and Carno Adit all flows to Fynnon Gisfaen in the Clydach Gorge 5kms away where DCWW can abstract 4,000 cu.m. daily for the Brynmawr public supply. Water sinking at Blaen Onneu Cave and Llangattock Mountain cave systems resurges at Pwll-y-Cwm much lower down in the Clydach Gorge and later joins the and out to sea.

The invention of dyed lycopodium spores as a water-tracing agent is attributed to [Drew, D.P., Smith, D.I., 1968, Techniques for the Tracing of Subterranean Drainage. British Geomorphological Research Group Tech. Pub. Ser. A, p.2-36].

Fig. 4. Carno Adit in relation to the local area

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Fig. 5. Carno Adit (blue) and the Ogof Carno cave (red) in relation to surface features

Geology

Mynydd Llangynidr is one of Britain’s finest examples of interstratal (i.e. limestone beds in between other rock types). Doline fields (i.e. surface collapses and depressions) within the grit outcrops are a special feature on gently dipping escarpments in South Wales, and Llangynidr has the densest, largest and most spectacular assemblage of these dolines. Collapsed dolines, broad shallow subsidence basins and large masses of foundered grit all occur within a small area here.

Caves form in the limestone beds, which in this case dip to the south. Water entering from the land above through exposed limestone or breaks in the gritstone cap will follow small cracks and faults in the limestone, widening them through solutional action, and running away down the dip. It is possible, as shown in the diagram below, that a large cave system has few if any direct connections to the present land surface which has been sculpted many times by glaciations.

Fig. 6. Stratification, surface collapses and solutional cave development beneath

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Fig. 7. Surface geology of Mynydd Llangynidr

There are two small caves in the middle of Mynydd Llangynidr: Ogof Cynnes is a cave with 900m of rift passages formed in the top beds of the limestone just beneath the grit cover, and Ogof Fawr (Chartist Cave) is another small cave accessible from the boundary of the limestone and grit. So both of these have grit roof at their entrances, soon leading down to rift passages and large internal collapse chambers which have no surface expression. About 9kms of cave passages lie in Ogof Carno in the Dowlais Limestone at a depth of up to 100m and they appear to be the down- dip continuations of influent caves such as Ogof Cynnes. But Ogof Carno is only accessible from inside the DCWW adit by sheer luck and it is not connected to any natural surface entrance.

Fig. 8. Chartist Cave entrance with its thin gritstone roof over the limestone

- 5 - Spelaeology

Cave features become evident in Carno Adit almost immediately it enters the Dowlais limestone at 1200m from the entrance. For example, at 1290m a side passage is met on the right which can be entered through a hole in the brick tunnel lining. This passage is 10m long and it formed while fully submerged in water. It now has shelved walls and a cap-mud floor. The mud has flowed in from the surface under high pressure during various glaciations to occupy a pre-existing cave.

The geological consultant’s report of 1912 mentioned the presence of a strongly draughting fissure in the limestone wall of the tunnel. This likely corresponds to a strongly draughting hole in the wall found by cavers. Their study of this draught, its dependence on weather conditions and its lack of moisture or surface smells, prompted the cavers to widen this hole and so access a natural cave chamber beyond it. But unfortunately there was no continuation into man-size passages.

A little way beyond the draughting fissure is a small area of collapse in the floor which sinks water in wet weather, again suggesting natural caves. The next 120m of the tunnel has some pools of water on a rough boulder-strewn floor and another sink for water at its northern end. The water is also ducted away from the tunnel by a small pipe laid in the floor. It was into this pipe that the dyed Lycopodium spores were introduced that gave the positive water trace to Ffynnon Gisfaen.

Just beyond this floor sink, access can be gained through a hole in the tunnel brick lining to a dripping aven (i.e. a blind vertical passage) some 6m high and 2m in cross-section at its lower end. Water issues from a small crack in the aven, cascades down the wall and flows along the tunnel to the sink. The vertical difference in height from here in the adit to the land surface is 65m. There are a few more natural side passages in this area, dug out when tunnel contractors followed cave features, presumably hoping to chance upon and tap any underground water source that would be vastly cheaper than tunneling for another 1400m to reach the Claisfer valley.

After abandonment of the tunneling project, the steel works water supply problem was solved by means of a new pipe being entrenched across the top of the mountain during the 1940s to pump the Cwm Claisfer water to Ebbw Vale, whilst acquiring yet more water from the area.

Fig. 9. Lifting system for rubble at the 1980s cave exploration site

The next cave discovery progress came in the early 1980s when the draughting cave features at about 1400-1500m from the entrance, near to the scene in the photo above, were dug out and explored. Despite much effort these did not yield any substantial discoveries of interest and

- 6 - interest waned. The mid-1980s, however, saw enormous discoveries over on Mynydd Llangattock where the Daren Cilau cave system was extended from just a few hundred metres, as it had been in the 1960s, to many kilometres of huge passages occasionally well-decorated with truly amazing speleothems. Daren Cilau thus captured and ignited cavers’ interests in the potential of this region of South Wales. Daren Cilau is of ongoing interest, now being the fourth longest cave in Wales, with 28kms of surveyed passages and holding the largest naturally enclosed cave cavity in the UK.

The Carno exploration re-started from 1986 a little further into the tunnel at the 1760m mark where there was another dripping aven. Entry up this was forced in various ways, and the opening vented a huge draught, but sadly, once again, there were no onward large passages.

The big Ogof Carno discoveries

The explorers returned to Carno from the late 1980s and instead dug into the floor below the dripping aven to follow the sinking water down instead of the more obvious air flow going up. A few stalactites had formed here due to solution and deposition of the concrete from the tunnel floor. A narrow crawl led off, which was widened, eventually ending at a ten-metre deep pothole which brought cavers by means of a ladder into a large chamber named Carno’s Last Stand.

Fig. 10. View of the widened crawl leading off below adit level (photos taken in 2010)

From the bottom of this ladder another small and rather wet passage continued that was named Desperate Duck although the thought of passing it was far worse than its wet reality. This led into a large sandy passage called Dune Chamber where a large muddy hole in the floor, known as the Mud Silo, would be avoided by traversing across the chamber walls above. The area beyond, called the Brickyard, had many loose-looking stacked rocks but in fact they were well-settled and nothing here moved. The cave beyond the blocks reverted to a narrow crawling character through tubes in solid rock to emerge in Whale Chamber, its walls covered with pretty Selenite (Gypsum) crystals – and this was the largest natural chamber yet discovered in Ogof Carno by 1993.

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Fig. 11. The 10m ladder after the widened crawl and the Desperate Duck beyond that

Fig. 12. Brickyard Area

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Fig. 13. Selenite crystals covering the cave walls

Fig. 14. Large passages in Ogof Carno lying beyond the Full Moon breakthrough point

- 9 - Further exploration in the 1990s

The newly-found large passages were explored upstream in the direction of Ogof Cynnes, to which Carno seemed to be leading. Many new avens here were climbed. The sumps downstream of the breakthrough point were also dived to look for an onward route in the down-dip direction.

The magnitude of the Ffynnon Gisfaen resurgence clearly points to a separate major cave system running to the south-west of the Llangattock caves, but the height of this resurgence in the geological series is not promising, in that it was near the very top rather than the bottom beds. This suggested that the water flows at an interface between the gritstone and limestone beds rather than through big cave passages which have developed within the main body of the latter.

Ogof Carno had grown to nine kilometres long when another major cave discovery occurred in the Blaenavon area: at Ogof Draenen in late 1994. Draenen had been a short cave prospect of a few tens of metres but with a good draught and dug intermittently by several generations of cavers over many years. Their ‘digs’ unexpectedly opened out into the proverbial passages measureless to man extending to dozens of kilometres of surveyed caves within a couple of years. As access into Ogof Draenen is quite straightforward compared to getting into Ogof Carno, the local interest never really returned to Ogof Carno, as is seen from the logbook numbers in the table below. Another issue is that older generation of cavers who did all the hard work to discover Ogof Carno have largely retired from the caving scene and the new generation of active cavers is largely unaware of its existence. The lack of accessible information about Ogof Carno is another obstacle yet to be overcome. This deficit is due to the main cave exploration being done before digital photography and social media became mainstream.

Year Groups Cavers Average Group Size 1993 135 534 4 1996 38 125 3 Fig. 15. Logbook statistics for Ogof Carno reveal the transfer of interest to Ogof Draenen

Rank Cave Name Length (km) Vertical Drop (m) Discovery Year 1 Ogof Draenen 75 151 1994 2 Ogof Ffynnon Ddu 50 308 1946 3 Agen Allwedd 33 160 1957 4 Ogof y Daren Cilau 28 232 1957 and 1984 5 Dan-Yr-Ogof 16 150 1912 and 1963 6 Ogof Carno 9 63 1991-93 Fig. 16. The league table of longest caves in Wales

But for occasional caving visits done since the millennium, which were organised through BCC, Ogof Carno has seen few cave visitors in the past 20 years, but the potential for a major discovery is still there. With the coming of the A465 dualling project in 2013, access was withdrawn due to the road works and landowner concerns generally over managing health and safety issues.

But with the dualling project section now completed and with 2016 being the Welsh Government’s Year of Adventure this seems a good time to ask for access to be re-instated, with proper respect on the one hand for H&S because of the occasional industrial uses of this man-made tunnel and on the other hand for both the freedom that comes with venturing into the natural world and discovering its features. As a member of one of the last groups to visit Carno said:

“I for one will be keen to go back and see more. What we saw of the cave didn’t seem as off-putting as some people have made out – rather lacking in pretty stalactites, but not too much like hard work.”

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A plan to re-open Ogof Carno for caving

There is sometimes the misconception that cavers are unintelligent or thoughtless. The truth is quite the reverse. Whilst cavers represent all life’s backgrounds and occupations, the majority are well-educated, considerate and careful people that go to considerable lengths to protect and conserve caves in as near pristine state as when they were first discovered for the benefit of future visitors, and to preserve the scientific and historic interest they may contain. All the caves mentioned in the league table above have no litter and no graffiti left by cavers. The only thing left by cavers is so-called ‘conservation tape’ to mark out the footpaths which later cavers follow so as to protect the undisturbed cave floor and the speleothems to either side of it. Figure 17. Conservation path taping

To the uninitiated, caves may be nothing but darkness, damp, gloom, apprehension or even terror as portrayed in ancient mythology. But for experienced cavers, the underground world combines many opportunities for adventure, discovery, research, physical and technical challenges, teamwork, astonishing natural scenery, and an escape from modern life’s pressures to somewhere that is quiet and timeless. We have put together a few photos and thoughts to explain the ethos and aspirations of true speleologists at www.linetop.co.uk/caveaccess/carno/cavesandcaving.ppt

Caving has also acquired an unfortunate reputation as a dangerous pursuit, but this is quite unjustified. The vast majority of cave rescue incidents in Wales now are precautionary searches when groups have become overdue due to not finding or completing their intended cave route quickly enough to avert the concern of friends or family when a group does not return on time. The last serious injury (broken leg) was in Agen Allwedd in the 1970s due to a rock moving. The common type of injury is some kind of sprain due to a slip. Such incidents may only require pain- killers, food and assisting the casualty to get out of the cave by themselves, albeit quite slowly.

There have been no caving accidents in or rescues from Ogof Carno, but two rescue practices were held there in the 1990s to prepare volunteer rescue team members, and a further practice could be organised as part of a plan to re-open this major and important Welsh cave.

The next step for DCWW is to decide in principle whether to consider this application for renewed access any further.

The Welsh Government’s Year of Adventure 2016 provides an umbrella for a re- opening since it aims to create and promote opportunities for new kinds of challenging physical activities to promote active and healthier lives. Fig. 18. Zip-wire descent across the Blaenau Ffestiniog quarries in the Year of Adventure http://www.visitwales.com/latest-news/2015/september/embrace-adventure-in-2016

- 11 - Following on, it would be necessary to consider the commercial nature of Carno Adit because it is an industrial site of a kind – until, that is, the visitors reach Ogof Carno which is the natural cave beyond the adit. In particular, a risk assessment and methods statements (RAMS) for the adit section needs to be developed in conjunction with cavers’ representatives, taking into account:

1) security of the portal because the adit is a disused mining feature and accidental entry by the public must be prevented 2) occasional planned discharges from the reservoirs into the tunnel and how to avoid or manage any cave visitors becoming delayed in the dry upper reaches of the tunnel until the water stops flowing out near the adit portal 3) as per (2) above but for unplanned reservoir discharges, if any are carried out 4) protection of the Ffynnon Gisfaen water catchment to protect the public supply 5) a booking system to obtain safety clearance from WWDC in advance for requested dates 6) key issue system for recognized cavers through the Cambrian Caving Council (CCC) or some other access control body, with a limited number of security keys for temporary loan.

We next explain two proven operational models to suit Ogof Carno. The first is to copy and adapt the CCC scheme with NRW which provides cavers with access to explore their disused metal and slate mines on forestry land across Wales. The other is an access agreement made by CCC and MOD for access to explore caves on the Castlemartin military firing ranges. Both situations have some similarities with Carno since both the disused mines and the military firing ranges are, in a sense, industrial sites and introduce unusual but not insurmountable access-control challenges.

NRW Disused Mines Access Agreement

This is a formal agreement with a written contract which took some years to negotiate. CCC officers have set up a non-profit company limited by guarantee (Cave Access Ltd) to act as the counterparty signing with NRW and Welsh Government Ministers. Cavers register with CAL by filling in a form and quoting their British Caving Association public insurance liability policy number and their club name. They can then enter the ten permitted mines as they wish provided respect is given to other visitors and in particular to any educational groups. Only one mine has any physical security by means of combination padlocks on the entrance grilles. Cavers send a report to CAL after each visit so that statistics can be compiled and any landowner issues followed up as necessary. CAL writes an annual report for NRW, or makes them aware sooner of any matters considered more urgent. The contract provides for a notional fee of a few pounds per year as monetary consideration for the access rights, but NRW has not tried to collect this.

The above system has worked well for the past two years, and NRW has kindly agreed from August 2016 to add an eleventh site (the Hafna Mine near Llanrwst) to the list of its former mines for which CAL has NRW access consent.

Military Firing Ranges Access Agreement

The Castlemartin military firing range system is another operational model to consider for Carno. The main business here is heavy tank weapons training but there are also small arms for infantry and special forces – not only for UK troops and services personnel but also our NATO partners.

This agreement was concluded quickly, in only a matter of a few months, with the Defence Infrastructure Organisation (DIO), the land management agency of the Ministry of Defence (MOD). MOD supports recreational use of its properties when there is no military activity, subject to certain security and safety requirements. Our caving scheme has the backing of local NRW conservation staff and Pembrokeshire National Park staff who represent the leisure and tourism interests.

- 12 - Firing ranges are industrial sites of a kind and potentially dangerous due to potential unexploded ordnance lying on the ground or some that has fallen over the cliffs or landed at sea. There are two sectors known as Range East and Range West. The former’s coastal margin is open to the general public for informal walking when no firing is taking place. The latter is completely out of bounds to the public, but DIO has developed a system to grant individuals who attend a health and safety briefing session a licence to enter the prohibited area for approved sport activities when there is no live firing. Essentially we reached agreement two years ago to extend their list of acceptable sport activities to include caving and discovering new caves.

None of the caves on the MOD land are gated or locked, but they are on vertical cliffs which block access to non-equipped persons. Our access system relies on goodwill, common sense and trust, which has been forthcoming on both sides. There is no written agreement or contract, and DIO has adopted an evolutionary approach to cave access – to start with a clear plan but also to learn and respond as one goes along, which is very much military pragmatism.

The Range East system is that cavers contact CCC with a requested date and possible alternatives. If the cavers members of a club that is affiliated to the British Caving Association then CCC will contact the DIO who check their requested date against the military activities and authorise a visit provided that there is only one group in any one cave per day. The cavers submit a post-visit report on the state of the cave and any issues such as encountering and needing to advise unauthorised members of the public about venturing into restricted areas and asking them to leave before any potential mishap occurs. So there are benefits to this both ways.

The Range West system is that cavers report to the gatehouse on any date when firing is not taking place. There is a recorded phone message and also social media to discover this. If the caver has attended the H&S briefing then they are given a badge to wear at all times on the range as they may be challenged by MOD staff. They can then visit any limestone cliffs and beaches where caves may be found, handing in their badge at the end of the day to sign off the premises.

MOD is very pleased with the way these systems are working out and they now plan to publish an article on these cave management schemes in their prestigious Sanctuary conservation magazine. Sample copies can be seen at https://www.gov.uk/government/publications/sanctuary

Access System for Ogof Carno

The most appropriate parts can be taken from each of the two agreements explained above and combined to create a new access agreement that best suits the Ogof Carno situation.

If DCWW prefers a written agreement, then the NRW mines contract could be used as a proven model to avoid new legal work. The counterparty to DCWW would need to be Cave Access Ltd rather than CCC since the Council is not an incorporated body and merely a small elected group which exists to represent caving interests rather than to run business relationships. Cavers would register for Carno access with CAL, and CAL would issue their permits under licence from DCWW. The disadvantage of a contract is its rigid nature when the actual needs turn out to be different from those envisaged, or there is scope-creep, and a general reluctance to expend more effort and perhaps legal costs in changing a contract. This is exactly the situation with NRW where the contract has being overtaken by events, leading to wider mines access being managed by CAL. For example, academics wanting mine access for research purposes as distinct from sport caving that the system was first set up to enable. So what is happening in practice is that NRW’s initial approach is evolving via memoranda of agreement that modify the way that the contract works.

If DCWW prefers an informal agreement, then the approach taken by MOD could be copied. It would just need one or more meetings, conversations and email correspondence to develop an agreed protocol and to document the methods, then to place any developments under review.

- 13 - The likely level of renewed caver interest initially will be very low: perhaps one group per month. This could be expected to grow eventually to a similar level to Ogof Draenen in its current ‘post- discovery era’ which sees 50 groups per year (one per weekend on average) with an average group size of 3-4 cavers, thus about 200 person-visits per year some of which are repeats by the same people. WWDC need having nothing to fear concerning excessive visitor numbers.

The worst contingency to be factored is temporary and unexpected closure of Carno adit due to an unplanned reservoir discharge. At Dan-yr-Ogof Show Caves, its management and cavers have set up an emergency dump containing food, stoves, camping equipment in case some group gets delayed underground by unexpected weather conditions leading to high cave river levels. This system has been used once only in the past forty years. Of course the Show Cave company cannot just “turn off the weather” so any marooned cavers would just have to wait it out at the dry camp facilities beyond the underground river passages. But with any unplanned reservoir discharges into Carno adit, the control will remain with DCWW who could create a short break to allow for an exit, and in the meanwhile the cavers would sit it out at an equipment dump positioned in the permanently dry section of the adit. As at Dan-yr-Ogof, this camp could be connected to the surface by field telephone to provide reassurance about the situation.

CCC thus invites an initial meeting with DCWW as a first step to scope what is practical to enable caving to resume at Ogof Carno now that the A465 dual carriageway in the Ebbw Vale area has been completed and the new entrance to Carno Adit has been built just underneath this new road.

Prepared by:

Stuart France Access & Conservation Officer Cambrian Caving Council The Smithy Tretower Crickhowell NP8 1RD

Tel. 07740 871845

Email. [email protected]

19th September 2016

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