Further digging
Feb 12, 2009
After a bit of a slowdown after the entrance excavation, exploration is back on track.
Last year, pushing of an old lead in a cave was restarted, which initially involved capping along a horizontal rift to widen it from ~6 inches or so to a more usable size.
The rock was relatively tough, and frequently, a line of 3 or 4 caps was only enough to weaken it, needing another line to finish the job.
However, working sideways was relatively comfortable, and steady progress was made, especially on some fairly extended trips, where I managed to putting in some long solo stints while another gut was doing some science stuff elsewhere in the cave.
Eventually, we got to where the passage widened, and after disposing of some boulders in the wide section, we broke through to somewhere much larger, looking down a narrow pitch into a chamber with a good echo - possibly the best find for a long time in that particular cave.
On returning with a ladder, we dropped a short pitch onto a sloping mud floor which led to the foot of the chamber with only a dubious lead crawling down over damp mud, soon getting very low.
However, across the chamber, the rift we had entered from continued, slowly rising at walking width and ~6m high until lowering and leading to a flat-out crawl over hard clay in a bedding which soon closed down, but which had a gentle draught.
A few more trips extended the crawl for ~10m to where it rose up to meet a low passage at a T junction, with the roof being one long and wide major bed.
One way closed down to what looks like a fairly long dig - a wide gap between sand floor and roof, but only 6" high, disappearing off into the distance, and seemingly heading towards an already-known area of the cave.
The other way went crawling down a mud slope needing a little minor digging, but led onto a rather better looking lead - the floor cutting down into a trench and diving down below the bedding, with the trench being fiklled with clay and boulders at the end.
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- Latest reply: May 19, 2009
Fourteen cubic metres, sitting in a cave...
Feb 10, 2006
As a distraction from actual exploration, we're currently involved in a bit of an excavation project at the moment.
One of the major caves has a [mined] entrance passage which passes under a section of natural cave full of clay and rock. The clay seeps down into a short crawl section, ensuring that people going into the cave end up covered, and carry clay into the rest of the [much cleaner] cave on their clothing.
Having had a partial clearance effort some time ago, since cancelled out by more slumping, it was decided that a full clearance operation, emptying the natural chamber and making a walking-height route into the cave would prevent the continual slow spread of dirt.
We managed to secure funding from a conservation body to pay for materials and our labour, which goes to the club, and should secure its financial future for a few years, but does involve us moving an esimated 14 cubic metres (30+tons) of rock and clay from the offending section to the entrance, and off down into the quarry below.
Due to a need to finish the work before the end of the funding body's financial year, we have to finish by the end of the month, and only managed to start last weekend, so we do have a bit of a job on, especially given the small number of potential diggers.
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- Latest reply: Aug 5, 2007
Not the mineshaft
Jan 21, 2006
Very little has happened recently on the mineshaft front, due to a combination of Christmas and some nasty doses of 'flu.
We went down another cave on Wednesday to continue bolting up a muddy rifty aven with the intention of killing the lead (declared dead by someone who rememberedd going up decades ago) and surveying out.
We'd only left a climbing rope rigged from the week before, up a ~12m climb held by a pair of on good 8mm bolts, and hadn't brought much rope gear (a total of one pair of cowstails and a handled jammer lacking either safety cord or footloops), so simply climbing up the rope wasn't an option.
'Not a problem', D had said 'it's not a bad free-climb, apart from being slippy'.
D went up first, carrying the drill and battery, and belayed by me from the bottom. About half-way up the swearing started in earnest, and I couldn't provide a huge amount of pull from the bottom, and was a little distracted by the possibility of falling rocks. The problem was soon evident - the previous week, D had bolted up using an etrier to climb well above the current-last bolt. Since the rift was fairly narrow, it was easy to stand on the etrier top rung and lean against tha back wall while placing the next bolt.
Not having the etrier put paid to that possibility, so direct climbing with nothing more than medium tension from me was the only way. He ditched the bag with the drill, clipping it to a bolt near the top, since he simply couldn't finish the climb carrying that weight.
He got safely to the ledge and clipped into the final bolt, and gave the message I could cease belaying. Very shortly after I slackened off and got myself some ability to move, a repeated banging indicated a falling rock, which I was able to quickly sidestep to move safely away from. After what seemed like a long time banging around, it finally impacted just where I'd been standing, but proved to be only about 10cm per side, albeit with some sharp corners that could have made it painful for a shoulder-hit.
Then it was my turn to climb. 'Not too bad, a bit like Poetic Justice', D said, trying to inspire me.
Now, Poetic Justice, in County Pot, in the Easegill system is one of may favourite little climbs - only about ~5m high, in a rift which is a maximum of maybe 0.5m 'deep', and which tapers off to both ends, which are ~2.5m apart.
For me, there's only really one main move sequence to get properly off the ground, and then a little caver-style climbing, jamming with any or all parts of the body to get a little higher to the point where the tyop can be easily gained. A few seconds of exertion, possibly, but always well worth it for the top-down view of people following who are too large, tall, short, or unfit to get up easily, or who don't know how to approach it.
Now, the aven climb was not really much like Poetic Justice. For one thing, the rift was just a little too deep in places to wedge feet&knees on opposing walls, and too wide to reach the tapering sides from some otherwise hold-free positions.
More significantly, rather than being linmed with human-smoothed rock and flowstone like its supposed northern sibling, this rift was liberally plastered with clayey mud which not only got slimier with every attempted foothold (which would have been bad enough), but which had another interesting feature. When finally getting some kind of feasible foot-placings sorted out, with sone vague handholds to assist them after spending a minute or two resting with feet braced on a hold and back against the back wall, it became apparent on attempted moving that one's back was now attached fairly well to the wall by a generous layer of compressed clay.
After much thrutching, I eventually managed to gain the uopper ledge, and pass the drill up on my slow way up. Between us, we probably wasted 1/2 hour to attain a height we could have reached in under 2 minutes each by regular rope-climbing.
Anyway, now being set up for more bolting and surveying out this dead lead, after a little more faffing and then some more climbing up a decaying mud slope by D, bolting on the way, it truned out that the lead was not 'dead, just leading to phreatic roof tubes that peter out to nothing' after all, but it led to a small chamber which in turn led to a 2m-wide walking-height passage, blind at one end but with an apparently eminently diggable calcited boulder choke at the other end. Someone had been in there before, but never surveyed, nor dug. This is all as reported, given the time we took it didn't seem worth my going to confirm this week, especially since we aould be returning next week.
However, we rigged a 20m static rope before leaving (and removing the climbing rope for some serious washing), and next week, we'll take our full rope-climbing kit.
It's funny - dropping pitches on a regular tourist trip, even a 50m or 100m drop is still usually just a number and a little longer time to ascend. When you've actually slowly climbed up even 12m, or (like in our most rfecent Yorkshire exploration escapade) watched someone bolt their way up a 20m blank wall over several trips while shivering at the bottom, it seems a hell of a long way down from the top , especially if you heard a rock taking what *seemed* like a long time to rattle its way down to final impact.
On Thursday, it took 6 passes of the climbing rope through our very efficient rope-washer until we stopped getting muddy water coming out (usual expectation: 3). Similarly, the oversuits, which even after muddy trips (are there any other kind in North Wales?) normally get adequately clean by one pass of the pressure-washer. This week, it took three.
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- Latest reply: Jan 22, 2006
The next mineshaft project
Sep 8, 2005
In February, we abandoned the 6-month long dig in a small N. Wales mineshaft, which was trying to find an way in to the nearby big shaft which linked to known (and only partially pushed) cave passage.
The main (big) shaft was covered over, and had been for some time - possibly since mining finished. In the '60s, access to the cave at the bottom was possible by another side-shaft which joined the main shaft ~20m down, but that side-shaft was comprehensively blocked, so we had worked on another side-shaft thought to be a potential easy way in to the big shaft. Some 20+m down, and ~40 tonnes of spoil later, the shaft died, so our attentions turned elsewhere.
However, there was still some residual enthusiasm, and the offer of a free 30 minutes of use of a JCB from the landowner resulted in the main shaft being uncapped at the start of last week.
We had expected to find a typical 1.5m diameter round shaft, but instead found a hole roughly 2.2m square. Given the shaft is over 50m deep, the landowner was naturally keen on having it made safe ASAP, so much work has been done since the opening.
The shaft top has now been cleaned down to bedrock, its sloping suface largely levelled, and four 3.5m long RSJs placed over the top to use as beams. By the end of saturday, we hope to have the beams concreted in at the ends, shuttering and a frame for an access hatch installed between them, and steel reinforcing laid in preparation for concreting.
Assuming we can get a ready-mix truck close enough to the entrance, the plan is to have about four cubic metres of concrete delivered and poured over everything, which should see the shaft secure for at least the next century, albeit at the cost of half the club finances. If we can't get a truck there, we may have to make the concrete with a couple of small mixers, which could be rather a long job.
Whatever the expense, in a few weeks we should be able to finally get into the cave passage at the bottom, though it now appears that the initial section 'may be little tight'.
However, with a drill and caps, or even our generator plus the hire of electric hammer, that should only be a temporary setback.
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- Latest reply: Dec 11, 2005
Science book project
Jun 26, 2005
After making a suggestion - "Wouldn't it be nice if there was a guide to popular science books...", and being unexpectedly called on it "Why don't you...?", I ended up writing a list of some of my favourites, sorted by science category, intending it to be a list for me to use when working out what to write about.
My list then quickly became *the* list, and after a short play around, it seemed useful to have a second article holding book summaries, linked to from the index page, and to have full reviews in individual articles, also linked from the main index page.
When it became clear it was a pain to manually rewrite the pages for each entry, I then wrote a program to generate the index and summary pages, producing all necessary links automatically, at which point it became clear that making a page listing all the authors would be pretty trivial, (again with relevant cross-links) so now I don't have to do any more manual page-coding.
However, faced with an index of books mainly without reviews or summaries, I have now started on a fairly heavy summarise-and-review binge in an attempt to make the page less bare.
I managed 5 reviews on Friday, but found it hard to do any yesterday, with my mind seemingly chock-full of ideas from numerous half-read and skimmed-through books all competing for attention.
I have done a couple so far today, and hope to be able to plough through some more in the next few days, but also that other people start suggesting, reviewing *and* summarising books.
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- Latest reply: Aug 29, 2006
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