Slab Pot - Grid
Ref: SD 6279 7993
At the middle
of April 2018 the Red Rose diggers, plus lots of itinerants, began a big
excavation on the previously known hole that’s almost in the village of
Casterton near Kirkby Lonsdale. Alan Speight and Alex Fletcher had a brief dig
here in 2013.The cave is in Urswick Limestone and was suspected to head towards
the risings near Casterton village. (The sites of interest were originally
recorded by Hugh St Lawrence in RRCPC Journal 8, page 65).
We had
originally been contacted by local County Councilor, ….... The purpose of this
endeavour, other than having a dig near a road, was to try to alleviate the flooding which occurred on the
road under the abandoned railway bridge leading from Wandales Lane and to this
end the Parish and County Council both gave their support and assistance. The
area has many sinks and resurgences which Andy Hall and Hugh St.Lawrence spent
many happy hours tracing to their eventual emergence just east of the village
itself. The main resurgence and its flood associate produce a sizeable volume
of water, the main one running quite happily even in the drought of 2018. The
hot weather proved to be pivotal in the exploration as only a few days were
hampered by rain and the digging was made much easier because the clay and eventually
sand remained dry, unlike most digs that inevitably turn into quagmires.
We were also
helped by being given permission from the owner, Roger, of the chicken-run
adjacent to the dig to dump our large quantities of spoil on his plot, a mere
stone’s throw, or wheel-barrow-push from the entrance. The local inhabitants
took great interest in our efforts and we regularly had groups enquiring as to
how we were getting on, as well as cyclists, walkers and motorists eager to
find out why helmeted people were emerging from a hole at the side of the road.
As digs go this one was very well appointed as there was a bench opposite on
which to have a brew, supplemented with a couple of garden chairs, thanks to
Eddy, the local mole-catcher. The trees
gave shade from the blisteringly hot sun, which melted the road surface, though
they did also allow the midges the same shelter.
Extract from log
book...............
Day
2 digging at Slab Pot. Tues 1st May.
Andy Hall, Steve Gray,
Ray Duffy and Boz.
Good progress. Removed
tree roots with Steve’s magic saw, dug a lot of material out of the floor. Capped
two large boulders and removed them and you can now stand up at the end some
three metres from the entrance shaft. We have a draft and made onwards progress
down and along. Side passage also needs work. Ray did excellent job walling and
tidying up the dry streamed at side of the road. Visit from Chairperson on
Parch Council, a party from the school, farmer from Fell Gate and several other
locals who were impressed with our efforts. Thinking of selling tickets as we
are now a local tourist attraction.
The entrance itself, under a large concrete slab, hence the name,
had been known for over thirty years and had seen some pre-emptive strikes but
over several months this intensified in 2018. By the end of the first few
sessions we needed an aluminum ladder to reach the bottom of the 3 metre drop
at the base of which the efforts progressed on two fronts.
One face was heading directly under the road where a gap could be
seen above the clay floor whilst the other front headed under the embankment
bordering the chicken run enclosure. The road dig face was enlarged until it
was possible to stand under the road and then went down, and down. A nearly
round and over a metre diameter hole just kept going until climbing out require
a rope for assistance. Returning after a week off from digging, Ray Duffy found
a large clay ball at the bottom of the pot that turned out to be a live
hedgehog, the creature was rapidly transported to the surface and released back
into the wild and gave the pot its name, Hedgehog Pot.
By the time the pot had reached a depth of 7 metres a ladder was
necessary to get back to the entrance floor but the summer heat had broken and
the floor of the pot gradually became wetter and eventually a metre of water
was encountered.
Presumably the local water table had returned to normal levels
after the drought and we were just below it.
Logbook..........
Slab Pot Day 3. 6th May We
opened up the blockhouse sink over the road using scaffold bars as rollers as
it is very heavy. We were able to drop down into the water filled blockhouse in
which the water is just below welly deep! The water runs off down a half metre
pipe to where it appears to sump. Any work here would
need machinery to clear out but the pipe does run to the north under
the track in the field. The hole in the field nearby leads to a tube down
through boulders and looks unpleasant.
The dig toward the embankment went for four metres through a
larger passage to a X rift with tree roots in the roof and the sound of a
stream through small holes in the floor of the south trending rift. Straight on
was a wall of layered sand and gravel filling the whole circular passage over a
metre in diameter
Just a couple of metres along the entrance passage a small hole in
the left wall from which a strong draught issued and this meant another digging
front was opened, as if we didn’t have enough hauling of buckets to do already.
The small hole needed some enlargement. Thanks to Alan Speight and
his bang licence. After a couple of
metres a 1 metre drop down into a very small chamber was achieved. Sam was sent
through and we were able to enlarge this from both sides. From the bottom of
this another small tube led off at an awkward downward angle and again needed
enlarging as the sound of a stream could be heard by those who weren’t deaf.
Logbook
extract......... 12th May
At this point Richard
thought he would have a look at the end of the passage we found last Tuesday.
When he got back he said “Why are we not digging at the end. I CAN HEAR THE STREAM
DOWN THERE!.” Moral of the story, do not send deaf twats to explore end of cave
first!
After much banging the Hugh-tube dropped into
an unpleasant passage from which a very muddy crawl was enlarged to gain a
small and mud-banked stream-way that went for 20 metres and was aptly named The
Chicken Run. Originally this passage was pushed by Hugh,
as the only one thin enough to fit through, it
was explored to the very bitter end by Sam Lieberman.
Sam Logbook
…...To fill in some detail of my ordeal on Saturday,
Having dropped the dye in, I set off down to the Chicken Run. It
hadn't improved, with a squalid puddle landing you in a squidgy bank of mud
around the sump where you first meet
the stream. I spent a bit
of time improving this area and dug a channel to drain the puddle down a bit,
though a rock lip prevents it being drained completely.
Then set off upstream keeping an eye out for the dye. I reached
the previous limit of exploration and crawling over a puddle and a gravelly
bank soon came to the duck as reported by Hugh. I spent a little while looking
to see if the water level could be lowered but that would have required digging
a trench back for 4-5m. Went back to consider the duck and knocked a few
protuberances off the roof, then went for it, helmet off, on my front. This
rose up after a body length and squirming over a couple of boulder obstacles
regained the low stream-way and another puddle to crawl through. It was around
this point I started to see colour in the water and continuing on to a small
widening with another large fallen slab the stream had turned a fine green
colour - a positive dye test! A small opening beyond the slab needed some rocks
clearing out to reveal a low body sized tube half full of water.
I tried lowering the water level by digging a little channel but
it didn't make the duck look any more inviting. Eventually after some
cogitation I decided the only way to attack it would be feet first on my back.
Feeling my way through by kicking my feet around, the roof seemed to rise up
after a body length so I carried on and found myself in a stooping height
widening with mud bank ahead and the water flowing out of a very low passage to
the left. There still seemed to be an inch of airspace and an echo beyond but
it wasn't going to go any further without a lot of work.
All the new passage, barring the bit that was too low at the end,
was heading in the same direction as the rest of the Chicken Run which would
take it towards the cone in the field, time to head back and give folks the
good news. Coming back through the ducks my suit was almost clean, but that
didn't last long. I did some more clearing of gloop from around the sump
area before heading back up. Sam.
Later Sam and
Zak Boznyak entered again to reach the final too low, wet and tight conclusion
after another 14metres. The downstream passage sumps immediately and a surface
survey showed that we were at same height as the rising in Casterton village.
By the end of
June we had exhausted two fronts all efforts returned to the embankment face.
Digging was at first so easy that the haulers had difficulty in keeping up with
the rate at which the spoil was arriving. However, after 5 metres the passage,
originally stooping height, started to rise up and the roof mainly of clay and
roots stayed level. Eventually the dig was abandoned as the roof was in clay
and it appeared to be heading for the surface.
Logbook.......... Slab Pot Saturday 14th July Andy
Hall, Hugh St Lawrence
Guest
appearance from Eddie the mole man.
Spent
first hour taking reading at risings and sink. PH, temp and hardness (ppm).
Results below. Rest of day digging out Hedgehog Pot. Over 80 bags hauled out
and some downward progress made but it could still be going horizontal to the
north, hard to say. Lowered pot about another 40 cm but it has quite a large
surface area now so progress down is slower. It seems to be getting damp at the
bottom.
|
Rising |
Sink |
|
pH = 7.04 |
pH = 8.3 |
|
Temp = 8.6 oC |
Temp = 18.5 oC |
|
Hardness = 198
ppm |
Hardness = 91
ppm |
Results
show that most of the water comes from surface sinks, not from deep Phreas (phreatic zone)
A final
parting shot was aimed at a small opening 2 metres up the road trench from the
slab. This was entered early on by Ray and Hugh and left as it ended after a
few metres in a clay and boulder walled face. As all other leads were exhausted
Hugh and Andy re-entered this and removed several buckets of fill and boulders
but this just appeared to be a filled trench, the roof of which was probably just
below the surface. So that was definitely the end of the story. We had failed
to find a downstream connection to the main resurgence even though it had been
positively dye traced from the Chicken Run. Was Slab Pot a phreatic riser? Had
blasting the small ridge to create the road that goes under the railway line
removed some feature? Was the water-table itself the ‘lake’ that some of the
locals remembered existing way back in antiquity?
Logbook........ September 22nd Slab Pot after
some rain .....Tried to roll middle
slab off to one side but managed to drop it into the blockhouse, which has
about 3 feet deep in water! Whoops! Faffed about with very heavy slab scaff
poles and slings for a bit until Steve arrived. More faffing about and it was
time for lunch and a rethink. Meanwhile Ray was doing an excellent job. After
lunch we eventually managed to get the slab out with extra scaff bars collected
from Langthwaite sink and Ray's contribution as well. Not a lot done after that
we spent some time talking to various local residents. Ray spent time pointing
up the rocks around the entrance with sand and cement. Hugh had a look down
towards the Chicken Run passage but found the bottom of the cave sumped up
below the squeeze at end of crawl.
By the end of
September things were coming to an end. We got funding from CNCC and Natural
England to cover the open hole with concrete beams and had the blockhouse dug
out with a digger. All had not been lost, however, as we had created a massive
space into which the flood water had to flow before it would eventually
overflow to the railway bridge. Only time will tell if we have alleviated the
flood problem but we made quite a few local friends and had a damn good time
doing so. An article was also written for Descent.
Those involved include:
Steve Gray, Alan Martin, Sam Lieberman, Bill Osborne, Alex
Fletcher, George and Zak Bosnyak, Bill Nix, Bill Sherrington, Toby Speight,
Hugh St.Lawrence, Alan Speight, Richard Bendall, Dave Matthew, Bob Daunton.
Hugh ad Sam
after breakthrough Andy in hughtube Slab Pot
Entrance
