Cuckoo Cleeves entrance needs a new lock
- Thread starter Duncan S
- Start date
Duncan S
New member
Thanks Wayne
Something has changed in the drainage of the field over Cuckoo. It is dramatic enough the farmer contacted the landowner of Tankard asking if we had upset the water table with activities in our dig. Our dig is dry, so nothing to do with Tankard. But it got our curiosity peaked to see if anything has changed in Cuckoo.
We'd hoped to find the Frome Dig dry and breathing fresh air like Mike and I saw during a Winter trip, but the weather is changing and we may well have missed our opportunity.
When the lock is changed Mike and I will pop down for a look just in case
Something has changed in the drainage of the field over Cuckoo. It is dramatic enough the farmer contacted the landowner of Tankard asking if we had upset the water table with activities in our dig. Our dig is dry, so nothing to do with Tankard. But it got our curiosity peaked to see if anything has changed in Cuckoo.
We'd hoped to find the Frome Dig dry and breathing fresh air like Mike and I saw during a Winter trip, but the weather is changing and we may well have missed our opportunity.
When the lock is changed Mike and I will pop down for a look just in case
Aubrey
Member
Do you have any more details of the changes the farmer was complaining about?
If the field wetter or dryer?
Which field, the one to the east or west of the wall?
I am interested because there was a major change in the air flow in the cave sometime in the 1980s. When we were digging the bottom of the cave in the 1970s and early 1980s the air was always clear even though we were banging one or two times per week.
In recent years the air has always been bad in the summer with very high levels of CO2. We have never been able to explain the change.
If the field wetter or dryer?
Which field, the one to the east or west of the wall?
I am interested because there was a major change in the air flow in the cave sometime in the 1980s. When we were digging the bottom of the cave in the 1970s and early 1980s the air was always clear even though we were banging one or two times per week.
In recent years the air has always been bad in the summer with very high levels of CO2. We have never been able to explain the change.
Duncan S
New member
Hi Aubrey,
I can't be 100% sure of the details, but I can tell you what I know.
Apparently, one hollow that has held water for years suddenly drained, and a couple of other hollows that are usually dry started filling up with water.
Tankard landowner Tim looked at Google Earth and tried to explain where he thinks the hollows are. He indicated the fields between Cuckoo and the road, and West of the wall.
Tim thinks the hollow that drained was in the field nearest the road, and the two that filled lie between there and Cuckoo.
I wouldn't recommend a reccie as the field is growing hay at the moment and trampling it would definitely upset the landowner.
Typically, hay will be cut in about a month from now.
The hollows can't be seen from the road.
Assuming the rain holds off, Mike and I might be able to squeeze in a Cuckoo trip this weekend to have a look at conditions underground.
No promises though - as I type it has started raining
I can't be 100% sure of the details, but I can tell you what I know.
Apparently, one hollow that has held water for years suddenly drained, and a couple of other hollows that are usually dry started filling up with water.
Tankard landowner Tim looked at Google Earth and tried to explain where he thinks the hollows are. He indicated the fields between Cuckoo and the road, and West of the wall.
Tim thinks the hollow that drained was in the field nearest the road, and the two that filled lie between there and Cuckoo.
I wouldn't recommend a reccie as the field is growing hay at the moment and trampling it would definitely upset the landowner.
Typically, hay will be cut in about a month from now.
The hollows can't be seen from the road.
Assuming the rain holds off, Mike and I might be able to squeeze in a Cuckoo trip this weekend to have a look at conditions underground.
No promises though - as I type it has started raining
Only about 7mm of rain forecast over the whole weekend, so shouldn't be an issue.
Could be as simple as the clay lining of the pond has been breached & the water that previously collected there is running on a lower clay surface into the other depressions.
Here you can see the pool suggested above (but there is also the bigger pond to the north (nearer entrance)):
https://www.google.co.uk/maps/dir/51.2469861,-2.6361759//@51.2474639,-2.6379376,497m/data=!3m1!1e3?hl=en
Mike (not Kushy)
Could be as simple as the clay lining of the pond has been breached & the water that previously collected there is running on a lower clay surface into the other depressions.
Here you can see the pool suggested above (but there is also the bigger pond to the north (nearer entrance)):
https://www.google.co.uk/maps/dir/51.2469861,-2.6361759//@51.2474639,-2.6379376,497m/data=!3m1!1e3?hl=en
Mike (not Kushy)
Duncan S
New member
Hi Mike,
It's definitely not the pond East of the entrance; that hasn't changed.
But the Google Maps shot you linked to definitely shows the depressions we think we are talking about. But it is unclear which depressions are now holding water.
Right place your bets for whether anything has changed in Cuckoo.
Mike K isn't available, he is digging in Sludge. So am going with Jon from the Templeton diggers. Plan is that if the Frome Dig is dry and air OK then I will go to Sludge and get the rest of them for an attack in Cuckoo. The morning trip with Jon is just a reccie.
Watch this space
It's definitely not the pond East of the entrance; that hasn't changed.
But the Google Maps shot you linked to definitely shows the depressions we think we are talking about. But it is unclear which depressions are now holding water.
Right place your bets for whether anything has changed in Cuckoo.
Mike K isn't available, he is digging in Sludge. So am going with Jon from the Templeton diggers. Plan is that if the Frome Dig is dry and air OK then I will go to Sludge and get the rest of them for an attack in Cuckoo. The morning trip with Jon is just a reccie.
Watch this space
bograt
Active member
A little education for those not aware;
'Dew Ponds' were often set up in natural depressions in the ground, most often on Limestone, they were usually lined with cobble sized boulders and sealed watertight with clay, if allowed to dry out and the clay to crack, they would lose there ability to hold water.
Not many 'dew ponds' around these days, but the depressions are still there ---
'Dew Ponds' were often set up in natural depressions in the ground, most often on Limestone, they were usually lined with cobble sized boulders and sealed watertight with clay, if allowed to dry out and the clay to crack, they would lose there ability to hold water.
Not many 'dew ponds' around these days, but the depressions are still there ---
Duncan S
New member
Jon and I are back safely - it proved a fairly tough trip
The Frome Dig was dry and a small stream was easily being swallowed into a hole on the right hand side. I used the pry bar to drag silt and pebbles out of the too-tight hole, ultimately reaching full arms length. It feels like the hole opens up on the other side to dimensions that a small caver might attempt.
I had a can of smoke and there was no noticeable air movement in the hole.
However, the digging was accomplished by two strokes and a long rest during which I failed to recover my breath.
Jon was perched on a ledge above me and after short while simply stated we should get out of the cave as the air was terrible.
He says his experience is that he has a higher tolerance for bad air than most cavers, and this was really bad air.
Jon's turnaround call proved timely as we both struggled getting enough breath and energy to climb out of the cave. And we both developed headaches where the air was at it's worst.
It seems one of the worst areas of bad air is just below the entrance pitch, and there was a point where both of us could see the ladder and all we could do was sit waiting until we got enough breath back to make the last few moves.
In summary - the Frome Dig is going!
But the air is horrifically bad and neither of us are recommending pursuing it until the air improves.
The Frome Dig was dry and a small stream was easily being swallowed into a hole on the right hand side. I used the pry bar to drag silt and pebbles out of the too-tight hole, ultimately reaching full arms length. It feels like the hole opens up on the other side to dimensions that a small caver might attempt.
I had a can of smoke and there was no noticeable air movement in the hole.
However, the digging was accomplished by two strokes and a long rest during which I failed to recover my breath.
Jon was perched on a ledge above me and after short while simply stated we should get out of the cave as the air was terrible.
He says his experience is that he has a higher tolerance for bad air than most cavers, and this was really bad air.
Jon's turnaround call proved timely as we both struggled getting enough breath and energy to climb out of the cave. And we both developed headaches where the air was at it's worst.
It seems one of the worst areas of bad air is just below the entrance pitch, and there was a point where both of us could see the ladder and all we could do was sit waiting until we got enough breath back to make the last few moves.
In summary - the Frome Dig is going!
But the air is horrifically bad and neither of us are recommending pursuing it until the air improves.
The Old Ruminator
Well-known member
bograt said:
I am pretty sure Vurley is next to a large dew pond. Certainly it was there prior to 1900 when there were farms up there, now in ruins. Still holds water well and occasionally overflows into the cave.
Early days on site showing the pond.
Fact 20: Over the last 50 years, the concentration of carbon dioxide in the atmosphere has increase by 30% due to burning of fossil fuels and greenhouse gas emissions like carbon dioxide, nitrous oxide and other gases, trapping more heat in the lower atmosphere.Aubrey said:
So maybe more of that carbon dioxide is being absorbed by rainwater & washed into caves. Those with a dynamic stream (e.g.Swildons) will carry the gas through the system, whilst less established streams (e.g. Cuckoo Cleeves & Manor Farm) may back up, allowing more gas to be released.
Changes in agricultural practice (manures & chemicals used) & more livestock per acre will also have had an effect & may also have increased the microbial fauna beneath the fields.
Cavers entering caves with poor circulation will also increase levels.
The following is taken from:
http://nhvss.org.au/wp-content/publications/Foul%20Air%20Rescue%20Australia.pdf
TYPES OF FOUL AIR IN CAVES Speleologists have categorised cave ?Foul Air? in three main types.
1. ?Foul Air Type 1?, is produced when CO2 is introduced into the cave atmosphere from ground water. This occurs because CO2 is absorbed by the ground water as it passes through surface soil containing high concentrations of the gas, due to the decay of vegetation. The resulting weak carbonic acid percolates through the rock strata and enters the cave system, usually taking part in the calcite deposition cycle before the CO2 is liberated to the cave atmosphere. In this instance it takes the addition of five percent CO2 to reduce the O2 level by one percent.
2. In ?Foul Air Type 2? the CO2 is a by-product of organic and micro-organism metabolism or respiration by fauna such as bats or humans. In this instance the oxygen concentration is reduced in proportion to the increase in CO2. The N2 concentration stays constant.
3. ?Foul Air Type 3?, is a cave atmosphere which has resulted from the introduction of other gasses, such as methane and nitrogen and the non-respiratory uptake of O2 as well as CO2 stripping by water. Another example is ?stink damp? so named because it often contains hydrogen sulfide and the O2 is significantly more depleted than in ?Type 2?. Foul air consisting strictly of ?Type 3? is rare in Australian caves, although some samples collected at Bungonia do suggest a few caves contain atmospheres partly influenced by this mechanism.
Mike
Yep, they don't help, but they were there long before there were such problems (unless previous generations of cavers were tougher & less susceptible to CO2 - which is possible as more of them smoked !)
Consensus seems to be that the majority of gas comes from biological sources, so the increase in heavy downpours will also be washing more organic matter underground, which becomes trapped & decomposes at certain points in some caves. Dry caves (even those under livestock) and caves with regular streams don't seem to have the same problems.
http://www.cru.uea.ac.uk/documents/421974/1295957/Info+sheet+%2315.pdf/8b8457b7-7bd2-49fc-888a-9b3f6785a40e
Over the past 100 years the intensity of UK precipitation has increased during winter, and to a lesser extend also during spring and autumn. This has been accompanied by more frequent spells of very wet weather and an increase in total precipitation, at least during the last 40 years.
Mike
Consensus seems to be that the majority of gas comes from biological sources, so the increase in heavy downpours will also be washing more organic matter underground, which becomes trapped & decomposes at certain points in some caves. Dry caves (even those under livestock) and caves with regular streams don't seem to have the same problems.
http://www.cru.uea.ac.uk/documents/421974/1295957/Info+sheet+%2315.pdf/8b8457b7-7bd2-49fc-888a-9b3f6785a40e
Over the past 100 years the intensity of UK precipitation has increased during winter, and to a lesser extend also during spring and autumn. This has been accompanied by more frequent spells of very wet weather and an increase in total precipitation, at least during the last 40 years.
Mike
Aubrey
Member
A few years ago we changed the gate on Cuckoo to be a grill rather than a solid plate so the entrance could breath. Is the grill still used?
The research I did into CO2 in caves pointed to the production of the gas in the roots of live vegetation on the surface above the cave. The amount of rotting matter in Cuckoo was insignificant.
When we were digging at the bottom there was a draft because we were sometimes chased away by the bang fumes. I think something has happened underground to block the air movement.
The research I did into CO2 in caves pointed to the production of the gas in the roots of live vegetation on the surface above the cave. The amount of rotting matter in Cuckoo was insignificant.
When we were digging at the bottom there was a draft because we were sometimes chased away by the bang fumes. I think something has happened underground to block the air movement.
