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Category: Digging



Big news! This taken from Descent magazine:

George’s Choke Yields to Saintly Power

by Stephen Macnamara

George’s Choke, photographer Chris Jewell, subject Stephen Macnamara
Canyon passage in the Mayfly Extension, photographer Chris Jewell, subject Stephen McCullagh
The downstream terminal sump, photographer Chris Jewell, subject Stephen McCullagh
New digsite at terminal sump, photographer Chris Jewell, subjects Stephen McCullagh (L) and Stephen Macnamara (R)

The Shannon Group has been busy over the past couple of months, and the hours of toil have paid off. On Saint Patrick’s Day (17th of March for the heathens among you), George’s Choke finally relented, to admit a group of three cavers into the downstream Mayfly Extension. The extension, named by the first explorers in the eighties, became inaccessible after the repeated collapses of George’s Choke. The nails were put in the coffin when the original cave entrance series collapsed about fifteen years ago.

The 2005 breakthrough from Polltullyard into Shannon allowed a new assault on George’s Choke to begin in earnest at the start of 2006. Some fifteen trips of gear transporting, digging, scaffolding, cementing, photography, surveying and lead pushing have been made, the average trip length being nine hours.

In September 2006, the group made a significant push through the worst of the choke into apparently stable, large boulders beyond. This trip was curtailed by light failure. Undeterred, we returned in the next month. Unfortunately, the choke now decided to reassert itself, almost incarcerating one of our key members … and another retreat was necessary. The subsequent trips were spent redoubling the scaffolding effort and applying lashings of quick-setting cement (mixed in a few saucepans which were retired from culinary duties for the purpose).

Saint Patrick’s Day was bound to be a lucky one, and we decided to retry the push. Back in the large stable boulders, an interesting right angle squeeze at floor level was immediately followed by a tight slot under a boulder into water. One further squeeze up through boulders found us looking into a sizeable chamber with the stream emerging in front of us. A short stroll led us out of the boulder choke and into the clean-washed streamway of the Mayfly Extension!

In comparison to the boulder-strewn passage upstream of George’s, the downstream extension is a luxury. Three hundred metres of stomping passage is only interrupted once by a minor choke. Much of this length is beautiful canyon streamway.

We quickly reached the downstream terminal sump, where the water disappears to resurface three kilometres later at Shannon Pot, the source of the Shannon River. An old dive weight was still lying on the ledge beside the sump. We did not spend too long here because the water level had risen by half a foot. The squeezes in George’s Choke were decidedly wetter on our return, and somewhat alarmingly, the normal crawl out of the choke had sumped off! Fortunately, we found a high level route before making a sprint for the surface.

On the latest trip, we checked the terminal sump for diving possibilities with the help of Chris Jewell and his diving mask, and concluded that there was indeed potential. A climb up into the boulder choke above the sump leads about ten metres further downstream, and then drops back to stream level, with a voice connection back to the sump chamber.

However, non-divers need not despair yet. About fifteen metres back from the sump chamber, before the boulder choke starts, Steve McCullagh spotted a sculpted ledge running along the left wall just below ceiling level. With a boost from Steve, I climbed up and crawled twelve metres into this sheltered tube, which seems to skirt around the edge of the passage and hence bypass much of the boulder choke. I rigged a handline and we soon made five metres’ progress through easily removed rocks. This is the most pleasant digsite we have encountered in Shannon yet, with a solid floor, wall and ceiling. Some minor shoring will be necessary, but the site seems very promising.

Work on the survey is continuing in parallel with digging. In addition, George’s Choke needs a bit more shoring work to make it safe for the level of traffic we expect over the coming months. We need more members please!



Well, because the various people involved with pushing the Shannon Thang further have been so busy over the last year, doing what they do best, there has been some neglection of the writing up duties… But fear not! Here are some recent articles from two highly-regarded caving publications….

Fat Tony


As published in Descent magazine, April 07:

More Leads Than You Can Shake a Stick At.

by Steve Bus

Over the last 12 months or so the Shannon Group have been carrying out some exploration in Shannon Cave. Within this period, at least fifteen trips have been made to the George’s Choke area of the cave, in the hope that a breakthrough can be achieved into the known passageway beyond. Although the digging is going well and a breakthrough is predicted in the near future, we have often been distracted by the many leads which were spotted during the long gear-carrying trips.

During late December/early January a number of exploratory trips were planned for the Mistake Passage area of the cave. On the first trip a bit of awkward climbing and a few well-placed bolts brought Steve (Bus) into a large high level chamber. After a bit of exploration an easier climb up was found. Within minutes of being joined by the rest of the party of Tony (Fat), Steve (Jock), Nigel and Ronan, an interesting phreatic tube was discovered (see photo [coming soon – Ed.] ). The passage led for about 100 m to a large gaping hole. We presume that this leads back down into the main streamway.

On the next trip Steve (Bus) and Eoghan M went looking for scaffolding bars which were deposited previously at the far end of Mistake Passage. At the entrance to Mistake Passage lies the only part of the cave which involves getting wet. Figuring it would be a long digging trip in a wet furry, a bypass was sought. Within minutes a tight rift was pushed into a large chamber which had a rather unappealing rift heading off in an upstream direction. Following this tight (and loose) passage for about 100 m, an awkward climb back down to the streamway was gladly taken. Although the wet section of the cave can now be bypassed, it is predicted that this bit of passage won’t be travelled often, as it easily deserves its new name of Pisstake Passage.

On the most recent trip, one of the high-level chambers was revisited, and after a bit of futering around another large chamber was spotted heading in a downstream direction. Unfortunately no easy access was found and we have no immediate plans of entering it.

All in all at least 350m of high-level passageway has been found in the last year or so. These passages appear to be found anywhere you dare to climb up, though when you look at the roof you’ll understand why more have not been pushed!

A survey of the new passageways in relation to the main Shannon streamway will be made as soon as George’s Choke succumbs to the digging onslaught.


Published in Underground, the SUI‘s publication, Jan 07:

Shannon Cave – An Update

by Steve Bus

Over the last 12 months or so the S3 group (a loose coalition of ex-uni cavers mostly made up from QUBCC) have been carrying out some exploration in Shannon cave. Within this period at least twelve trips have been made to George’s Choke, in the hope that a break-through can be achieved into the known passageway beyond. Beyond this choke is the carrot of 400-500 m of stomping passageway terminating in an undived sump with potentially a few unpushed leads. The dig itself is reputed to be around 20-25m long and has a notorious reputation for trying to entomb unwary cavers.

The first half of the boulder choke has now been shored with copious lengths of connected scaffold bars reinforced with concrete. However, we have now reached the ‘crux’ of the problem – a tight squeeze surrounded by loose boulders. On two of the trips the squeeze was pushed into a small chamber with a huge boulder (solid) making up the roof. Leading off is a small passage between secure boulders where the stream can be heard yet again. Unfortunately the way on has not been found but not all leads were pushed due to a combination of failing lights and the nasty habit of boulders in the squeeze conspiring to entomb us. The end of the small passageway must be very close to the break-through point. Plans have now been made to shore the squeeze before further progress is made.

During the long, long gear carrying trips to George’s choke, a number of high-level leads have been spotted. Several of these have now been climbed and at least 200m of passageway was found. On one particular outing a climb was pushed to 15m above the streamway whereby a ‘bold’ step lead into a high-level oxbow approximately 40 m long. The passage contains many impressive formations but the crowning glory are the helectites, some of which are at least 10 inches long (see photo [coming soon – Ed.] ). These high-level passageways appear to be found anywhere you dare to climb up, though when you look at the roof you’ll understand why more have not been pushed!

A survey of the new passageways in relation to the main Shannon cave will be made as soon as George’s choke succumbs to the digging onslaught.



The digging noticeboard has been fairly quiet recently but QUBCC diggers (and others) have not been. We’ve been quietly moving equipment down to our next project in Shannon Cave which will either be George’s Choke or the terminal choke upstream Mistake passage. The trip to this region of the caves takes about 2.5 hours without any gear but loaded down with scaffolding bars can take up to 4.5 hours.

Over the last 6 months since the breakthrough there have been at least 12 trips (5 to the end) and we’ve managed to find three large high level chambers along the streamway with potential for many more.

George’s Choke may require a lot of shoring but it would be worthwhile in the end as the Shannon stream goes for at least another 500m to a large undived sump with the potential for a dug by-pass.

The terminal choke in Mistake passage is a strange one. A dig in the stream may well become too awkward but we’ve managed to climb high up (approx 25m) just before the choke so there may well be a way of getting round it. This passageway has huge potential as the stream comes from at least 1km away (proved) and it may also be part of the illusive link to pigeon pot in east Cuilcagh 5 Km away – Now wouldn’t that be a through trip to remember!

We have also started doing some preliminary investigation in Co. Antrim, so go see the website.




Well it’s finally happened! After years of digging down Polltullyard the diggers have broken into Shannon Cave. Steve Bus’ report below is from an email post today. Enjoy:

Hello all

For those of you not on IDC you mightn’t have heard that after a large number of digging trips we have eventually broken into Shannon Cave from Polltullyard. For some unknown reason even though we had figured that we had still a lot of work to do, on the saturday of the breakthrough we decided to bring down a videocamera and a camera with flash. Video recorded images of actual exploration are in the link below although most people seem not to be able to open the source a different version will be uploaded soon.

Over this summer (and indeed over the next few years) we intend to have many trips into the system to first explore then survey the system. The potential of the cave for new discoveries is such that on the first trip I managed to find a large phreatic tube (Roughly circular about 1.5m in diameter) that is not on the survey but leads of for at least 10 m around a corner. Although entering it would have been easy the shear exposure (10 m above the streamway) prevented me from doing so.

At least another two going leads (not on the old survey) have been spotted and we’re only about a quarter of the way through the system!

To put this in context. We (Stevemuh and me) have been actively digging in caves in Fermanagh for the last 5 years and all we’ve found is about is a measley 50 m of new passageway. The formations in the cave are pristine and probably the best I’ve seen. So on Sunday we taped off some areas of the cave to keep them that way.

As for access and other details see Les’s email below. However, if you’re keen you are always welcome but the entrance system, the old Polltullyard cave and the newly found passageway, are quite difficult so be prepared for a difficult (So much so that one of the passages is being called the Re-Birth canal – watch the video) but very rewarding trip.

– Steve Bus

From Les Brown:

Well its taken a several years of on and off digging and then 9 months of hard work but we have managed to engineer a route back into Shannon Cave! So, the official new entrance to Shannon Cave is via Polltullyard. Needless to say Shannon is probably the most dodgy cave around. It is exceptionally loose (that is the WHOLE cave not just the dig) and the new route is bloody awkward being not just tight but tight for a fair distance. Yes, Dave Ma we found you another Crucifixion Crawl! Full details should be appearing in the next issue of the SUI Newsletter.

I’ve uploaded a few short video snippets from this weekends exploration here – all are in Quicktime MPEG-4 format.

They can be played on VideoLan available here. So firstly, the list of diggers over the last 9 months, Ash (TCD), John G (TCD), John M (DCU), Ronan (DIT), Steph (DCU), Mark (QUBCC), Eoghan M (QUBCC) Stevie (QUBCC), Stevo (QUBCC), OZ and me. If I have left anyone out let me know.

Well that’s the easy bit over with. Next plan is to survey from Polltullyard to Shannon… yes folks that’s well over 2.5km of passage. I think we are going to need more folk.

As for access, we are presently using taping off fragile sections of the system. Due to the dodginess of the system and difficulty with route finding we’d politely ask that if folk want to get into the system please have a chat with us first. Or even better tag along on one of the many trips that we’ll be having into the system over the next few months.

– Les



Right so its been a while since the last update. However thats not to say that all digging has been put on hold. The new year has seen frantic digging commence again in Poltullyard. The dig known once as hanging death has been safely secured with techniques that would make even Blue Peter proud (toilet roll tubes and sticky back plastic reportedly) and is beginning to create interest again despite Les’s recent encounter with falling rocks. Stevey Muh and a few others are away dwn again today so keep an eye out for updates. In the meantime there are a few photos of the dig here for your amusement.