Kiln Piece Hole - A new entrance to the Slaughter Stream Cave system?

[PeteHall]

As part of a long-term project in Slaughter Stream Cave (Wet Sink), a fresh look at Kiln Piece Hole seemed overdue.

This abandoned dig terminated after two awkward pitches in a small chamber (2m x 1m) with a gravel floor sloping to a shallow pool, carrying a flow. A downstream connection to Pirate Passage in Wet sink had been proved with dye testing, while upstream was thought to be fed from Hole in the Hedge. A low airspace could be seenfor circa 1.5m downstream, while upstream was sumped immediately from the chamber.

After Tim Nichols and Co. regained access to the cave last year, I volunteered to try diving the sumps at the bottom, making very little progress in grim conditions. My recommendation was to build a dam, bail the sump and dig it in "dry" conditions, so a plan was hatched to return in the dry, summer weather.

Over the next couple of trips a survey was produced, a dam was built and some of the awkward bits on the way down were enlarged.

That was spring 2024, and as you might be aware, the dry summer weather that year also brought us a little breakthrough in Redhouse Lane Swallet Cave and for some reason Kiln Piece took a back seat...

In the next few posts, I'll bring you up to date on progress, including a link to another excellent film by @Adventure Traveller

 

[PeteHall]

Roll forward to summer 2025 and after a bit of Redhouse burnout attention returned to Kiln Piece Hole. It was by now, as dry as it's ever likely to be, so Dan and I went over on a Friday afternoon to take a look. We brought a few bags, a drag tray and a few tools, hoping to find the sump dried out, withan easy dig ahead.

To our great disappointment, the water wad exactly the same level as it had been before, but it was clear that there had been a significant flow through since the last visit in February. The bag dam had been partially washed away, along with some of the plastic pipe that had been used.

We set about rebuilding the dam and bailing the downstream sump behind it. Interestingly, the water level downstream was dropping quicker that it was rising behind the dam. This was good news, meaning that the sump ahead was relatively short, and the storage volume upstream relatively large; definitely the best result we could have hoped for.

After an hour and a half of bailing, the sump was fully drained and looking ahead, it appeared big enough to fit down easily enough, though it was obvious why I'd struggled to fit with diving kit on.

After a low flat crawl of roughly 10m, a gravel bank lead up into a reasonable sized chamber (2m x 6m), later named "Blind Optimism". A blind rift to the left gave a potential place to pump away water, while the route on was a very low and wet passage. It looked like there may be an inch of airspace ahead, and there was a noticable draught, so the way ahead was definitely open.

The floor of Blind Optimism was gravel and the water level ahead seemed lower than the roof of the sump, so it seemed like it would be possible to permanently drain the sump.

While I did a bit of digging, Dan was furiously bailing, trying hold back the water that was rapidly passing the leaky dam. With water finally emptied again, Dan came through for a look and we spent a bit of time chatting, digging and speculating, before suddenly realising the level of the water in the sump.

I made an aqueous dash back through and got back to bailing while Dan did a bit more work in Blind Optimism.

After removing the pipe bung to drain the dam, we exited the cave after about 5 hours underground, extremely pleased with progress!

 

[PeteHall]

With high hopes for a through-trip, two teams organised for Sunday 29th June. One to survey Pirate Passage and push the end, the other to try lowering the water in KPH.

Ian picks up the story in another of his excellent films:

 

[spelfish]

Blimey! That redefines 'collectors piece'.

 

[Goydenman]

gulp.... that was hard going. Great effort

 

[Tritim230]

We've had several trips to Kiln Piece Hole (KPH). I'll continue the story before I hand back to Pete for his news following the
trip on the video, you will note that I was on surface duty, still recovering from my eye operation, so frustratingly out of the thick of the action.

Falkland, James, Dan and Paul were underground. Paul brought a submersible pump down and also set up Meshtastic nodes. This allowed the team at the bottom to communicate to me at the top to start/stop the generator. The system worked fantastically and was invaluable for follow-up trips.

The submersible pump required over 60m of cable to get down 42m of pitches and along the passage length. It made short work of the sump and proved a real time saver for future trips.

The next trip was an important step forward, so over to Pete when he went back down with Dan and myself (first trip underground for a month).

 

[PeteHall]

Friday 4th July.
Dan S, Dave, Pete, Tim.

The team met at a large layby nearby and we loaded caving kit, 5 bags of post-fix concrete, a new battery pump, a reel of 1 inch hose, a petrol generator, and the Meshtastic kit into my Land Rover and drove over to the field next to the cave, with kind permission from the farmer, saving a substantial carry!

Dave was on surface duty and set up the generator and checked comms via the Meshtastic kit; this system of Bluetooth transmitters has been briefly mentioned on the Forum before, but I'd never seen it in action and I think it has the potential to be a really useful tool for both digging and rescue. One for another thread perhaps?

I was down first, followed by Dan, then Tim, lowering everything down in stages. Once at the bottom, I set the generator-powered pump (still in from last week) running to drain downstream sump in an upstream direction, behind leaky dam.

By the time Tim and Dan were down the sump was drained, so I took pump, spare lay-flat hose and one end of the 1 inch tube through the open sump. The idea was that if the sup filled, communication could be maintained via the tube, though in the end this was not needed and the tube was just annoyingly in the way!

Dan and Tim removed bung and started dismantling the dam, allowing a huge volume of water through to sump 1, which was pumped downstream into the ongoing passage. After some time monitoring, the water level downstream did not appear rise at all, so I set off downstream following a good draught.

I managed to pass a desperately low airspace duck (1 eye and one nostril out of the water) moving extremely slowly and carefully with helmet off and face pressed into the ceiling to reach a better airspace and ongoing passage which was followed to a small chamber with space to sit up and turn around, having come to this point feet-first. Ahead after a couple of metres a chamber (5m x 2m) ended at a blank wall with a cross-rift at floor level heading off to the left. This was low airspace and looked very constricted, so it seemed a good time call it a day, particularly as the pump was still delivering a healthy flow down the passage and anything that may restrict or block the flow could have had serious consequences for the way out!

As it was, the duck was worse (I hadn't thought that could be possible!) on the way out I narrowly escaped drowning as I got a nose full of water with the rest of my face underwater in a constricted muddy tube. Fighting every reflex to gasp for breath, I managed to drag myself through to where the roof lifted a couple of inches and I could regain my composure. This was certainly not he most pleasant bit of cave I'd ever visited!

Counting body lengths on the return, the new passage was estimated to be 50m long, so roughly 70m from the base of the pitch in a southerly direction after Sump 1 and Blind Optimism Chamber.

By the time I returned through the now well drained Sump 1, the upstream sump was well open and Dan and Tim suggested it would be good to look at it, but neither volunteered to go, so I squeezed through an initial constriction and continued upstream for approximately 20m, until the roof dropped to another (undrained) sump. This looks like it could likely be pumped pretty easily in future, and hopefully we'll get time to look at it while we've still got power and a pump in the cave.

Pete Emerging from the drained upstream sump. Photo by Tim Nichols

Finally Dan and I built a better dam using the post-fix concrete and rocks (also with a pipe and bung) while Tim set off up the pitch to start hauling kit out, including the unused battery pump.

Overall, a very productive afternoon!

Tim and Pete after a successful trip. Photo by Dave Hardwick

 

[Tritim230]

Trip Report KPH 6-7-25: Underground Paul, Jon Forster, Tim; surface: Craig

I tried to start up genny but it was clear there was no load. Quickly down the cave, somewhat less load than with 100kg of postcrete on Friday! I placed in Craig’s Meshtastic nodes and proceeded to Sump 1. Meshtastic worked well - could have used less nodes as it turns out... At the bottom the water level hadn’t risen much and was about 1” below the top of the 4” drainpipe.

I attempted to go through (on my front) without bailing to see what the issue was with the pump, but at the bend I was spluttering and getting caught up in the small diameter plastic hose in the way. I proceeded to hand bail and dropped water by 2” and went through. Still couldn’t get pump to start (turns out me not understanding the float switch….)

I went back to figure out how best to survey the route and decided to put a stone at the bend and do a forward shot from the bottom of the pitch and a backward shot from the other end. This meant I could keep all survey kit dry. Since I had managed this OK on my own, I left Jon to look after the dam to bail a bit more out and I surveyed the rest on my own.

Paul came down and sussed the problem with the pump. By this time I had completed the survey almost to where I think Pete had to single nostril breathe. I did splays to this point – it was extremely hard to keep the Disto out of the water, so practically couldn’t go any further without lower water/support. I was getting pretty cold by this point as well.

Paul moved the pump downstream and pumped back into the rift. There was some mud in the pump but after clearing, Paul managed to drop the water level by an inch or two. However, the water was seen flowing back into the downstream passage....

For the next trip, we figured the best option would be to pump the water back into Sump 1, effectively closing ourselves in, but this could be bailed back behind the dam with somebody at the bottom of pitch 2.

19m surveyed south heading towards Wet Sink ….

Over to Dan for the follow-up trip.....

L to R: Tim, Paul and Jon after completing the trip. Photo: Craig Cameron

 

[Dan S]

Following on from Pete and Tim’s reports, here’s the next instalment from 11/07/25. Another sunny Friday afternoon jolly down KPH turned into quite a significant day in Forest caving - Slaughter Stream Cave is now a multi entrance cave system! Team: Tim, Dan, Falky and Craig.

Craig, Tim and Dan met at 2.45pm and drove over to KPH, with the generator again, ready for another water pumping session, to see if we could reach Pete’s nostril breathing extensions. Falky was planning to meet us later, after work. Craig set up the sun shelter and settled into a hot session of turning the pump generator on and off, when he got messages, via his excellent Meshtastic link up. Tim and myself went down, set up the pump and quickly cleared sump 1 water back behind the dam (it works really well, with very little leakage.) We then took the pump through to sump / duck 2 and started pumping the water back into sump 1. The plan was, if it was just the two of us, we would have to pump the water back into duck 2 at the end, as we would have sealed ourselves in. Luckily Falky had arrived just as we started pumping and set to bailing the rapidly filling sump 1, back to the other side of the dam. Thanks Falky – My hero!

Duck 2 was lowered by about 4”, until the pump started to complain about the amount of shit going into it. We put it to the side and peered forward – Kinda looked ok, if a bit damp, so we set off, following Pete’s squirm prints, from the week before. Not too bad – kept heads out of the water along a tight, muddy tube - definitely a lot lower than when Pete went through. We got a small chamber, that we assumed Pete stopped at. There was a little slot in the corner, that we squeezed through, back into a wet, muddy tube, with ear wetting ducks. Eventually, (maybe 50/60M in all? We didn’t survey) we popped out into a gravelly chamber – Was this Ian’s end chamber he got to at the end of Pirate Passage? It felt right, but we didn’t see his shovel, that he said he left behind. Undeterred, we continued on and there seemed to be obvious ‘caver’ signs – We were pretty sure we had made it to Pirate Passage, but had no definite evidence. We carried on and it got tighter (sounded like PP), until Tim cried out with joy and happiness that we had found a survey point! Finally, a connection had been made! I was just glad we could turn around and get out of there.

Worked our way back, still not seeing the shovel (Ian later commented in the pub, that he put it quite high in the chamber, to keep out of any winter floods, so I guess we just missed it). Sump 1 passable thanks to Falky and we got out to the surface caked in mud, packed up and went for celebratory pint in the evening sunshine, later joined by Ian, who got the exclusive ‘hot off the press’ story on video.

So, the through trip is now on..

Tim and Dan - Before

And after..

 

[tdobson]

Incredible report - and great news.

Will you manage to get Ian back in PP after he swore "never again" if he takes the short[er] cut from KPH?

Would absolutely love to see the follow up to part 1!

 

[Tritim230]

Incredible report - and great news.

Will you manage to get Ian back in PP after he swore "never again" if he takes the short[er] cut from KPH?

Would absolutely love to see the follow up to part 1!

If no thunderstorms, Ian will be back from the Kiln Piece end to film for the first ever through trip.
Who could miss that!

 

[Long Drop]

Any prospect of being able to keep the new entrance open without needing a generator/pump each time? (Syphons, dams, etc?) Just curious!

 

[Tritim230]

The dam is permanent with a pipe and drain, as the passage is normally an active stream.
It can be bailed by hand as it has been during our visits.
The stream isn't currently flowing.
It remains to be seen if it will be passable in normal summers.
I hope so, but we don't know yet.

 

[PeteHall]

It took about an hour and a half to fully bail first time we did it. That was with a leaky bucket (originally made as a hauling bucket with drain holes, but all I had in the shed at the time), and a leaky dam that we were building as we bailed.

With a permanent dam that doesn't leak much and a purpose made bailing bucket, I reckon it should be possible to drain Sump 1 in half an hour by hand.

Bailing the following duck back upstream into Sump 1 would be harder work, as there is further to move it, and you'd potentially be sumping yourself in.

It would be possible to make a hopper and pipe to bail directly from the duck back behind the dam, but that's not something we've set up yet.

 

[ChrisB]

Is a bucket the fastest way to bail? For emptying flooded sea kayaks we use a hand pump. A hose can be attached to the outlet to move the water to elsewhere, although I suspect a few metres and not much height would be the limit. Worth a try if there's enough room to use it?

 

[PeteHall]

Is a bucket the fastest way to bail?

Other than an electric pump, yes.
You can bail about 15-20 litres every few seconds when it's full. That reduces as the level drops and you can't get a full bucket each time, but if we dug a bailing sump, that would allow the rate to be pretty well maintained.

Bailing also only needs a simple bucket, so nothing to go wrong, unlike a pump.

 

[Rhys]

I once had a kayak bilge pump for draining a dig and priming a siphon. It worked very well for a short time, but the seal got destroyed by silt and grit very rapidly. I never managed to source replacements.

 

[Tritim230]

Also, we hope to complete the survey partly during tomorrow's trip and the remainder shortly after.
We'll write up a route/rig description and as soon as Mark is back from Brazil, he'll update the Slaughter survey.
There will be a full write up in Descent, and a presentation at Hidden Earth.
Just a note to say that one can exit Wet Sink from the inside but at present one cannot from KPH. This is something we need to address.

 

[PeteHall]

Just a note to say that one can exit Wet Sink from the inside but at present one cannot from KPH. This is something we need to address.

Unless Kiln Piece Hole is left permanently rigged, this is a moot point, as groups would need to pre-rig (and bail) if going in that direction anyway.

I suspect that any future traffic (limited as it's likely to be), will enter via KPH and exit via Wet Sink, de-rigging and locking KPH afterwards.

 

[Tritim230]

We will sort out a better solution to the entrance/lock at KPH as I suspect it will prove to be a 'bucket list' trip.
It is on Forestry England land, just off the Wysis Way and they request it is locked. It would be a terminal end to any passer-by that tried to enter it without the appropriate tackle.