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Life, the Universe and Eastwater Cavern.

By Phil Rowsell (alias Madphil)

My fascination with Eastwater Cavern can be attributed (or blamed dependant on who you are!) to Tony Jarratt (J-Rat).  After the break through at Stock's House Shaft, I was looking for a new project to keep myself occupied over the summer.  Tony introduced to me to Adrian Hole (now my digging partner in crime) who was also intending to spend the summer digging.  Adrian had originally intended to push a few leads in Swildon's but with its closure due to foot and mouth, this was obviously a non starter.  Eastwater Cavern was the next option, Morton's Pot and the illusive connection to Lambeth Walk.

Morton's Pot/A Drian Hole Dig

I had been down Eastwater many a time before, but never down to Morton's Pot.  I always remember the first trip.  I learnt on the way down that Adrian had been one of the digging team that had pushed Morton's Pot 5 years ago.  They had found another vertical pitch below Morton's Pot named A Drain Hole (an obvious name connection).  They had dug down to a depth of approx. 5m before weather closed the dig for the winter. Disaster took place when the surface stream bed was cleared by the farmer and over a short period of time, the diggers watched the dig filling back up with silt to the top of the pitch. Man, it must have been a demoralising sight.  Since then no one had been back to dig.

We spent most of the time clearing the silt traps in the top of the 380ft Way and dumping the spoil in the rift before finally heading down to look at the dig.  The trip down was a bit tight and narrow but not too bad. The dig site itself was now filled up to a small chamber above the pitch, so we had no idea where A Drain Hole was.  It looked easy digging, mainly sand, but I just kept thinking about the problem of getting rid of the spoil.  Hauling it back to the Lower Traverse was going to be a real ball ache.  A couple of seilbahns had been put in place to assist hauling, but these were in pieces.  Everything would have to be replaced and a few modifications may improve things.  Being an engineer, this was right up my street.  The dig was a good challenge, I was sold.

Over the next week or so, equipment was salvaged and the seilbahns reinstalled.  Several modifications were also made to reduce the number of people required to move spoil.  It was highly unlikely that we would ever have the luxury of 10-15 people to haul bags that the previous attempt had had.  The mere mention of helping to dig Morton's Pot, often led to a rapid exodus from the Hunters, leaving you sat in playing Billy no-mates! Progress was also made at the dig site, the chamber was excavated and the bagged up spoil used to line the bedding plane heading up to the base of Morton's.  This would hopefully help future bag hauling up to Morton's Pot. On our 6th trip down, we finally discovered the ladder bolt over the top of A Drain Hole, a great boost as at least we knew where we were and had to go, down!

Despite lining the bedding plane, hauling sacks up the bottom of Morton's Pot still proved difficult. A 3rd seilbahn was installed down the bedding plane which sorted the problem.  The base of Morton's Pot rapidly filled up with sacks and our supply of empty sacks was exhausted again.  We had no option now but to transport the sacks out and empty them in the Lower Traverse. I guess we had to check out the hauling system sometime.

The lack of volunteers meant we had to do the hauling in stages.  The most awkward stage was to move sacks from the base of Morton's Pot to the bottom of the 380ft Way.  Fortunately we developed a method to do this with only 3 people.  From here, Adrian and I could move the sacks up the 380ft Way and dump them in the Traverse on our own.  A slow process but we had no other option if we were to keep the dig going. The first batch we emptied (50-60 sacks) we found we had a high mortality rate as almost two thirds of the sacks were badly holed.  Examination of the hauling system revealed the 380ft way seilbahn to be the culprit. The system was modified to a skip slung between two pulleys.  This was a great improvement, reducing the effort required to haul as well as dramatically improving bag life.

The dig and hauling continued on its slow painful progress, generally one digging trip to four or five hauling trips.  Occasionally the hauling would get a boost with the addition of press ganged volunteers. Our highlight came one Wednesday evening when we managed to hijack the Wednesday night digging team and had a total of 6 people (the most we ever had) hauling bags.  The complete system got a good test, moving bags from the base of Morton's Pot up to the top of the 380ft Way.  Some 60 sacks were moved in the space of 2 hours.  Great to see, the bags flying out of the place!  Unfortunately this only happened once, but it proved the system.  It also showed us that this would be possible to do with only 4 people but at a reduced rate. If only we could have found a couple more regular volunteers.  Frustration or what?

 

Ivan Sandford hauling in the 380 Foot Way - during the last Morton's campaign in the mid 1990s

Each time we moved bags from Morton's Pot and emptied sacks, it gave us the chance to dig again. Initial progress was slow, due to the awkwardness of digging at the top of A Drain Hole.  Once sufficient room to kneel up was made we took off and rapid progress was made.  Each dig session was measured by the number of rungs we had exposed, generally 2-3 rungs a session.  At rung 12 we found the old platform with a number of tools, among them Tony's prize miner's pick.  At rung 14.5 (4m from the ladder bolt) we dug into water which was a big surprise as the weather had been dry for the past few weeks.  As digging continued, it was evident that the water was draining back from the undisturbed fill on the sides. It was as if we had hit some kind of water level.  To make matters worse, it was now early September and time for the schools to go back. I now lost my digging partner who had to return to teaching kids once again.

Obsessed, digging continued solitary.  Thankfully Trevor Hughes came up with a massive supply of new sacks which helped delay the necessity to haul and empty until I could press gang anybody into helping. The conditions at the dig site didn't improve and I continued with the dig partially in water until nearly waist deep where it became impracticable.  Nightmare, needed a solution.  The idea of taking some drums down to bail the water into seemed feasible but they wouldn't fit through the rift at the bottom of the 380ft Way.  I eventually hit on the idea of walling off half the dig site with sacks, and bailing the water into survival bags, creating a sort of dam.  I could then dig the exposed half down a metre or so, dump the water, rebuild the dam on the other side and dig the other half.  With the total dig area only about 0.7 x2.5 m wide, it was pretty cramped work.  The system worked pretty well, and I even had the dig totally dry at times but it proved a very labour intensive and time consuming method.  I was still digging though.  To create more digging/damming room, I dug back into the rift toward Morton's Pot, forward progress being barred by a large rib of rock.  I was surprised to see the well developed rift continue rather than pinch down as expected.  With more room, I continued digging on down and eventually hit hard and "original" fill.  We had finally passed the previous effort.

The solving of the water problem had in itself created another, getting rid of sacks out of A Drain Hole.  It was impossible to do it on my own.  I installed a 2nd platform on which to stack bags, and this also served as a staging post to lift the sacks up to the first platform.  By triple or quadruple handling the bags I could get both platforms full of bags.


This was stacking room for about 50 sacks, but it still didn't get them out of the pitch. Occasionally I would manage to persuade someone to help me haul bags out of A Drain Hole into the little chamber and allow me to keep digging.  Progress was really slow as much of the time was spent man handling bags around and moving the dam etc, but digging continued.  The dig got down to a depth of 6m (from the bolt).

There was good encouragement at the dig face too in the fact that a rib of rock that was blocking forward progress (as opposed to down) was moving back to the right resulting in the rift opening to full size below it (Figure I - Section along AB).  With luck if forward progress was made, a drain point for the pot might be intercepted.

Disaster however stuck on the 3rd October when heavy rain resulted in the dig being flooded to a depth of 2m (4m from the bolt).  There was no way of damming this amount of water!  I guess I had been digging on borrowed time for some time as the weather had been remarkably dry for September.  Nightmare, my number was finally up and I had no option but to clear and put it to bed for the winter.  I monitored the dig for several trips keeping myself occupied surveying and tidying up. The water fluctuated in depth; after very heavy rain it would be flooded up to the bolt and in drier times it would have drained back down to 4m from the bolt.  It never however drained past the 4m mark.  This was also the water level initial intercept when digging down in dry conditions.  Figure 1 shows the survey of the dig site.

Dig Observations

The drain off point of the pot seems to be at the 4m mark, below which it is terminally choked. This level also corresponds to the base of a small calcite curtain that has flowed onto the top of the rock rib (see Figure 1).  This may have protected the fill below it, preventing compaction and hence the believed drain path.  The base of this curtain was poked with a bar to approx. 1.5m, and loose fill found, but rapid draining was not achieved.  With the pitch now being clear of fill to well past this point, it will be interesting to see whether this will clear itself over the winter.

The rate at which the pot drained also posed an odd question.  In high flow, the drain rate observed would not be sufficient to remove all the water, but there was little evidence of water backing up further than the little chamber (foam on roof).  This mystery is believed to have been solved when on one monitoring trip, a plastic digging sack was found to have been washed to some depth into a small (3") worm hole near the bolt.  This hole was originally believed to be an inlet as it headed upwards toward the Upper Traverse.  It appears that in high water, the pot backs up until water 'U' tubes up this worm hole to flow off to an unknown point.  This may be of great significance as it provides a possible place where water from the bottom of A Drain Hole may be pumped away.  This has not been investigated.

In Figure 1, the Section along AB shows that approximately 4m below the bolt, the rift opens out in a forward direction but forward progress is barred by a rib of rock sandwiched in between the rift.  As previously mentioned on top of the rib is a small calcite curtain, under which the pot is believed to drain.  Consideration was given to removing this rock rib, but the dig flooded before this was undertaken.  If removed, it may provide access to an open drain point.  It is also possible that the removal of this rock may prove unnecessary as at the 6m point, this rib of rock had cut back to the right face opening to a full size rift once again.  This will only be determined in dry weather when digging is resumed.

When digging back towards Morton's Pot to enlarge the dig site, it was a great surprise to find that the rift continued to be well developed rather than pinch down.  Only a metre or so was dug in this direction and probably connects to a small pot which was dug and subsequently back filled in the little chamber.  It does however have some interest to the Soho Dig (explained later in the article) the potential continuation of the wide rift development is of great significance.

A computer model of Eastwater Cavern

Conflicting rumours were abound in the Hunters as to where the "Morton's Pot" dig would eventually break through.  Some said Snotrom Aven, others Lambeth Walk where bang wire and pieces of digging sacks had been found, allegedly washed in from Morton's Pot.  After all the pain hauling those sacks out, would I be mad if we just broke in to Snotrom Aven!?  The only way to really tell and explore the possibilities was to generate a computer model of Eastwater Cavern.  This would enable easy viewing and more importantly, to be able to rotate the views around and obtain a good understanding of the relational orientation of the various passages.

The only survey commercially available was that done in the 1950's by Warburton & Surrall.  The survey was known to be of high accuracy, but it had some problems that could affect the tying in of subsequent surveys; the entrance to the cave was now in a different place and Dolphin Pot has also partially collapsed. 



The major problem however was that none of the West End Series was on it.  This had been partly surveyed and drawn up in the late 1980's but the data never published.  I felt sorry for the boys in the Hunters again, as if I wasn't badgering people for digging sacks it was survey data!!  I have to thank Trevor Hughes particularly, Tav and Tony, who supplied me with data.

Converting the Warburton survey back to readings to enter into the computer package, was painstakingly slow, involving much computation.  This process had also to be conducted on the Southbank as the only data available for this was a map produced by the Moodys in a WWC log book, and Morton's Pot data produced in a BB article (Vol 48 No 6).  Thankfully most of the other data supplied still had the original or transposed survey readings.  As the accuracy of Morton's Pot was fairly critical, it was resurveyed from surface, both the new data and that lifted from the map were in fairly close agreement.  Figure 2 shows a plan and Figure 3 shows an elevation through the complete Eastwater system.

The plots show that there are some discrepancies in the data, particularly in the West End data.  Where surveys overlap, or two data sets are available the discrepancies seen are not huge +/- 5 metres.  The West End series, however is an open loop system and thus with no closure it is difficult to assess true positional errors at the lower reaches of the cave.  Furthermore, the Southbank map is believed to be only Grade 2. Despite these inaccuracies, it does give an idea of relative positions to a reasonable degree.  The system begs however, to be accurately re-surveyed.

Points of Interest from the Survey

In Figure 3, the cross section, it can be seen that the majority of the cave is made up of a number of washed out bedding planes that are generally interconnected by rifts and vertical pitches.  The bedding plane has an approximate dip of 32 deg and strike of 168 deg.  This seems to be true of the West End series including Southbank and Lambeth Walk.  What is not apparent and was highlighted by T. Hughes's work, was that most of the big pitches (Primrose, Cenotaph and Gladman's) in the cave line upon an approximate bearing of 243 degrees, possibly indicating a joint or fault plane.  What is of great interest is that A Drain Hole also falls on this line, possibly indicating the presence of another large pitch. In addition, it can be seen that the position of A Drain Hole is not in the vicinity of Snotrom Aven, and it is not thought that this will form a connection as has been previously suggested.

The Southbank data wasn't added until A Drain Hole was flooded. Its significance to A Drain Hole is apparent as shown by the conjecture lines on both the plan and cross section.  The data seems to indicate a straight line connection between Soho and Lambeth Walk, i.e. both seem to be on the bedding plane. This also passes directly beneath A Drain Hole.  This is very interesting as it may well support the theory that the bang wire and sacks found at Lambeth Walk may have indeed washed in from the Morton's Pot dig area.  Furthermore, if a vertical pitch is dropped from the bolt in A Drain Hole down to the assumed Soho Lambeth Walk bedding plane (a vertical distance of 35m) the base of the pitch is 83m from Lambeth Walk, but more significantly only 45m from the Ifold's tunnel in Soho.  This definitely warranted investigation.

The Soho Dig

Fuelled with what the computer model was indicating I was keen to have a look around in the Soho area.   The chance came on a trip to rig the ladder pitches in the West End with Andy Heath.  We were in no rush so I said I would like to spend a bit of time looking around Soho, to see if I could find any possible lead at the base of Soho shown by the survey.  The original survey notes of Soho showed that two passages had been looked at but choked or were too tight.

There was a stream running out of the Ifold's tunnel heading down the bedding plane, so I decided to try and follow that, the thought being it could possibly be part of the Lambeth Walk stream.  It was quite open to start with but gradually got tighter, having to kick boulders out of the way.  I was pretty sure with the distance I had gone, I was past previous attempts.  I could hear the stream gurgling over what sounded like a small waterfall.  Driven by this and the dream of finding the connection to the base of A Drain Hole and more hopefully Lambeth Walk, I pushed on past a very tight 'S' bend squeeze, to finally sit up in a tiny rift chamber, somewhat relieved!  The chamber was shoulder width and approximately 2m long. An abrupt corner at the end of the chamber prevented further progress, but the passage opened up into a well developed 5m plus high rift, which continued along on approximately the same bearing.  It had a good stream running in the base, but looked fairly narrow in places.  A few bangs and we should be able to get a better look and pass the corner.  Well promising and what the survey was indicating.  Thankfully the squeeze turned out to be easier on the way out. I was buzzing!!  I think I floated down to Blackwall Tunnel and back!!

Five further trips to drill and widen the passage were accomplished.  My various companions had varying degrees of success negotiating the squeeze.  After the first bang, blown from Ifold's, J-Rat and myself were surprised to be chased out of Ifold's by the bang fumes!!  Big draught, very encouraging.  The bang widened the chamber, but still did not gain access to the comer.  It did however give a much better view of the rift.  The rift seemed to be narrow for 2m, before opening out to body sized passage. Encouraged, the passage was measured and found to be some 16m from the Ifold's tunnel, only 29m from the projected base of A Drain Hole.  The 2nd bang was blown from the Strand so that we could wait about for a bit and then see the results.  This time no quick extraction took place and I sat with J-Rat for over an hour in the Strand before the fumes finally cleared enough to go and have a look.  The bang had done a great job.  It had widened the passage right down to the comer and given enough room to potentially squeeze through the narrow part of the rift hopefully into the body sized rift.  The bang debris was quickly cleared, and I made an attempt.  Man was this tight!!  No go.  More kicking debris out of the floor and on the second attempt I eased through and stood up in rift passage.


The author returning through the second of the squeezes


The way ahead in the Soho Dig.

Jubilation, but it was only short lived.  The rift continued on for as far as the eye could see, but after approximately 2m closed down to 20cm wide and looked like it was a fairly constant width.  It also didn't look as though there were any high level routes either, but difficult to tell with the place still shrouded in fumes. We headed on out.  I was bitterly disappointed that I didn't get to solve the riddle of Morton's Pot, JRat was jubilant that he was going to get a pint after all and that he probably wouldn't have to go down to that desperate place again!!  His classic quote was "you have to kiss a lot of toads to find a princess"!

The rift still looked well encouraging; well developed, at least 5m high heading off into the distance and survey wise tying in with that above Jepson's Dig and heading straight for Morton's/A Drain Hole.  Not willing to admit defeat, I headed down another time to survey the dig properly and have a proper look around, hopefully able to see a bit more being clear of bang fumes!  Andy Heath again came to the call for help and another trip down to Soho.  Thankfully he made it through the squeeze into Thank-god Chamber.  I pushed on through the 2nd squeeze, but found it really awkward this time.  At one point I thought I wasn't going to make it through!  I eventually stood up in the rift with a clear view.

No doubt about it narrowing down to about 20cm for the majority of its height.  There was however encouragement at stream level. Further down (3-4m) it looked like it opened out to passable passage, but the immediate section looked very tight. I had a go at squeezing along the floor, but this was well out of my and most people's league!  No chance of digging out the floor as it was solid rock! Bummer.  It would need a number of bangs to pass this section to hopefully get to wider passage.  Where I could stand up the rift continued on up as a body sized rift, so I chimneyed up to 4m, but found I couldn't pass an awkward narrow part.  The rift did seem to continue on up at this width, and this needs to be checked again to make sure a high level by-pass is not missed.  The view from this height also confirmed that the passage did seem to open out at stream level further along, but it would need some widening to get to this point.  Resigned, we surveyed back out.  Figure 4 shows a survey of the Soho Dig:


Dig Observations

In Figure 5 - a survey plan of the Soho area, it can be seen that the found passage (rift) lies almost directly beneath the rift connecting the 380ft Way to Morton's Pot.  This rift was originally a deep narrow development but was back filled by previous digs.  It is suggested that this is the same rift development as the Soho Rift found. Further support is taken from A Drain Hole which is again a rift development that also follows the same trend line as the 380ft Way - Morton's Pot rift, the Soho rift and a conjectured connection to Lambeth Walk.  This could possibly indicate the possibility of a fault plane or a joint which has been eroded to the rifts presently seen.  The Lambeth Walk connection is pure speculation, but it seems to fit the evidence well and is supported by the digging debris which is found there.  Much less speculative is the probability that the Soho Rift will connect with the base of A Drain Hole, the rift following the same trend and only being 27m away. In the near future, it is hoped that some form of water tracing will be undertaken to determine this, or whether this water appears at Lolly Pot as has been previously suggested.


The Soho rift is accessed by two fairly awkward squeezes the 2nd being particularly tight, yielding a 2m section of body size passage, before narrowing to 20cm preventing further progress.  It does seem that the rift does open out at stream level after 4-5m. To access this however, selective widening will be required, involving a number of trips (and drop hammer techniques rather than bang).  It may also be necessary to widen the squeezes, particularly the 2nd to allow "normal sized" cavers (fat bastards!) access.

Unfortunately with my departure to Tasmania to cave for 6 months, it is unlikely that this will be pushed until next summer.

Thanks

First and foremost, I have to thank J-Rat for his support and advice, the supplying of articles, surveying data, digging bags and equipment etc.  In addition, the trips to A Drain Hole to help pull out bags and lately, the trips to widen the Soho Dig.  Much appreciated.

A big thanks to my digging partner Adrian Hole, again for his support, time and ideas, both with A Drain Hole and the Soho Dig, and lately for his help in writing this article. A big thanks also goes to Andy Heath for his help digging and sack hauling in Morton's and his help with the Soho Dig.

A thanks also to Ben Barnett who has spent many hours pulling sacks through the rift at Jepson's Dig, despite the rift being too narrow for him to get down to the dig site; Bob Smith who has also done several trips pulling bags out of Morton's Pot, almost the only times he had been underground this year; and Trevor Hughes for the supply of invaluable survey data, and a massive supply of digging sacks.

Finally, a thank you to all the people who came down to help dig or pull bags at both sites.  I hope to see you there again next summer!!

References

Jarratt A.R. "History of Morton's Pot Dig" ,Belfry Bulletin Vol 48 No 6.