Growling Swallet: The Niggly Connection Project

Photography: LIZ ROGERS


Background: JF-36 Growling Swallet is a particularly extensive and significant cave in the Junee-Florentine area of Tasmania, and has been known since the time of early European settlement.

The cave has a very impressive opening in the form of a slot in a cliff, with a significant creek flowing into it in summer, and by all accounts a practically unimaginable torrent of water in winter. The water has been dye traced to emerge from Junee Cave, approx. 8km away as the crow flies and Growling Swallet is generally considered to be one of the major feeders to this system.

With over 11km of surveyed passages, many of which are of “master cave” proportions, and at present four entrances, the Growling Swallet system is big — and complicated. Being a streamway cave with lots of water, there are inevitably passages which terminate in sumps.

Additionally, only about 500m separated it from the nearby Niggly Cave, which apart from having Australia’s longest free-hanging pitch (a ball-breaking 190m) is a big system in itself. Also a probably more likely (and exciting) prospect is making a connection to the Porcupine Pot/Tassy Pot/Owl Pot master cave system which is kind of in the middle.

There is big potential for discovery of gigantic “classic master cave” streamway passages, which already exist in Niggly, which ends (both upstream and downstream) in gigantic rockpiles.

The Project

Obviously, connecting these systems would be a significant achievement, and the Dreamtime Sump in Growling Swallet has the best prospects for doing this underwater.

It had been dived before in the 1990s without much success in the good direction, but Andreas Klocker (the fiercely anti-mainlander Tasmanian resident of 12 months) thought with the passage of time, improving of equipment and (at least as Sandy put it) “balls so big, they had to be put on my chest” there was a decent chance someone could get further.

Thus Andreas got together what I am going to call “The Niggly Connection Project”. Over the course of four trips through the summer of 2014-15 and the project now on hiatus until next summer, we are going to call Phase 1 complete: we have successfully extended Growling Swallet by an extra 500m, most of this being underwater. It is now only 200m from the likely connection point in Niggly, although this is in rockfall so may difficult to achieve.

The Trip to Dreamtime Sump

After a reconnaissance trip to Dreamtime Sump by Andreas earlier in the year, December 2014 saw grand caving wizard Alan Jackson with sorcerer’s apprentice Dan Haley spiriting a pair of 7l tanks wrapped in the wetsuit of Andreas Klocker to the top of Avon’s Avon under the guise of a “beginner trip”. And with only a small amount of convincing by Andreas, this set the scene for the first dive trip which took place on Saturday December 13, along with the arrival of Liz Rogers, Dave Bardi, Sandy Varin, and me (Stephen Fordyce) as the mainland Sherpa (insert suitably derogatory comment here) and moral dive support contingent.

Dan watches Dave repacking one of the tank packs and wonders how on earth he was roped into this. Alan grins maniacally.
Dan watches Dave repacking one of the tank packs and wonders how on earth he was roped into this. Alan grins maniacally.

As usual, Andreas did a stellar job of preparations and picking us up from the airport – I was on an earlier flight and as I was the alternate diver, we double checked the gear and packed my drysuit, brought along with much weight-related creativity on crummy Tiger Airlines.

Wearing your kneepads under jeans makes for a good place to hang all sorts of heavy caving gear that will otherwise make your carry-on luggage too heavy. My only regret is that the only people I had on hand to share the experience with were the unamused Tiger Airways staff.

Anyway, we got to the cave on Saturday morning and were underground about 10am. It was a hot day and we were glad to get out of the sun, until after 15 minutes of climbing down wet rocks in 10°C Tassie cave air, and that was a distant memory for the next 12 hours.

The cave is obviously a very active streamway that sees a lot of water so is not much decorated in most places, but still pretty in a shiny-black-rock-with-mud-on-it kind of way.

There were some bypasses that we took, some careful edging around the outside of pools, and crawling along ledges, so that most of us had dry feet and relatively dry undersuits by the time we reached the turnoff from the water, and crawled up into a small dirty passage past gigantic mudbanks with flood debris 5m higher than current river levels. A comforting thought …

Q. How many cavers does it take to eventually put a diver into a sump 5 hours away from the cave entrance? A. It depends whether they are mainlanders and whether you like getting out before midnight.
Q. How many cavers does it take to eventually put a diver into a sump 5 hours away from the cave entrance? A. It depends whether they are mainlanders and whether you like getting out before midnight.

There followed some interesting obstacles, starting with the windy rift, having a draft so strong that teeth were quickly chattering, while bodies and bags were wedged in awkward positions.

The fun continued with some more improbable squeezes, and several sphincter-clenching ladders (both up and down), which have been in the cave possibly since before Alan got rid of his trendy mullet. Oh, and also Herpes III – a lovely little squeeze in ankle deep mud that smells nasty, and you have to wallow in it to get through. Sadness levels increased proportionally with sock wetness levels.

As Andreas pointed out – rich people pay a lot of money to get mud like that smeared all over them, we should consider ourselves lucky. Perhaps we should bring some out and leave it in Andreas’ shower next time.

Artist's impression of Andreas' shower complete with Herpes mud
Artist’s impression of Andreas’ shower complete with Herpes mud

The complicated breakdown passage through Necrosis and Bronchial was bigger but we had to pay attention to find the way through as it was very complicated and despite the heroic attempts by the survey & mapping teams, the map was about as helpful as Sandy’s offer to lend Alan her spare trogsuit.

Now having the tanks and wetsuit made for a much heavier load, as we negotiated the rockpiles and contemplated bringing in bigger tanks to slow Alan down and stop him complaining about the mainlander pace.

Finally we heard the sounds of the stream, and we reached the “running passage”, which Andreas had insisted was so big and smooth we could jog down it. Sadly, the visions of a concrete walkway complete with handrail quickly evaporated, but we did make good time over the cobblestones.

A minor muddy detour up and over “Bloody Smokers” to avoid dunking ourselves in the stream and after a final slippery climb-and-slide we were at the Dreamtime Sump, with strict but largely futile instructions not too muddy the water flowing into it.

The trip out is … like most trips out of caves. Did I mention it’s 350m of vertical to climb (no SRT but still the sketchy ladders) and seems to see us getting out well after dark every trip.

Diving Trips

Dive Trip 1: The first dive trip was limited to a pair of 7l steel tanks, pretty standard kit for seeing if it goes, but giving you a decent bit of gas if it does. With Andreas ambivalent about transitioning to his wetsuit and back again, I was to have first go in my drysuit, so with the 1990s map in my head, I stuck to the right-hand wall and went in.

After wriggling through rather a lot of uninspiring wide but very low flat passage things started to open up and I was able to swim, dropping to 3.5m water depth before coming up into an air chamber, complete with small beach, room to stand up and another sump. The sharp left turn in the sump came as a surprise as I swam into the wall in the low visibility, but opened up into the “She Goes Tunnel”, a comfortable 4m wide x 1m high running in very shallow depths only just below the water table.

I quickly exhausted the 150m of guideline and had to return with an empty reel but relatively full tanks to report that “She Goes”. I should mention that as there was 180bar left in Andreas’ tanks, he was unanimously outvoted on the subject of whether they should be left in the cave for the next trip.

With no more guideline available to be laid, Andreas was understandably unkeen to go for a pleasure dive, but there followed an impressive motivational effort where instead of making a beeline for the exit, we made a scenic detour into the Dreamtime Passage, with nice high ceilings and wide walk-along floors.

Dive Trip 2: Unfortunately there were some equipment malfunctions early in the dive, so no further progress was made – such is life sometimes.

Dive Trip 3: With an earlier start and making good time through the cave (with the help of “new” recruits Michael “Pax” Packer, Ken Murrey and Dave Taberner), we were a well oiled machine moving at slightly more than one third optimum Alan Jackson speed.

This trip was a great success, with a further 350m of guideline added through the course of a two hour dive, and the full 500m surveyed on the way out, revealing the cave was only 200m from Niggly! It was agreed this would conclude diving for the summer and to pull out all tanks, while leaving the weights (and guideline) in and hoping they survived the winter.

Chillin' at camp comfort, where the team waited for about two hours. Despite the smiles, chillin' was a compulsory activity.
Chillin’ at camp comfort, where the team waited for about two hours. Despite the smiles, chillin’ was a compulsory activity.

Diving Details

This concentrates on diving trip 3, in February 2015. By this point, the gear requirements and configurations were pretty well sorted, to make sure we would have the opportunity to get maximum return (new cave!) for the effort we would put in to get everything there. I was to be the diver, and the equipment for the dive was selected as follows:

  • 2x 9l carbon fibre tanks with 6kg of weight strapped to each
  • 1x 7l steel tank – clipped “over the top” of the carbon fibre tank on my left
  • Drysuit with 7mm hood, Fourth Element “Arctic” undergarment plus polypro thermals, and a thick synthetic jumper
  • 4.5kg of weight on a weightbelt
  • 10 yellow silt pegs
  • 3 reels with a total of 500m of line (there was no way I was going to run out again!)

The gas plan was to dive in breathing only the 7l steel until it was basically empty (15bar), then dive out breathing only one of the carbon fibre tanks (unless it got too low to make an exit on if the full tank failed for some reason), coming out with two largely empty tanks, and one full tank which could be left in the cave for next time, while still maintaining enough reserve gas to safely exit the cave in the event any piece of equipment failed.

My recorded gas pressures at various points were:

Point in the dive 7L Steel 9L C.F. 9L C.F.
Start of dive 240bar 240bar 240bar
End of sump 1 (“Dreamtime”) 200bar 240bar* 240bar*
End of previous line 170bar 240bar* 240bar*
End of sump 2 (“She Goes Tunnel”) 145bar 240bar* 240bar*
Furthest point reached in sump 3 (“Niggly-Bound”) 15bar 240bar* 240bar*
Return from sump 3 to “30m Long Lake” 15bar 110bar* 240bar*
End of dive 15bar 60bar* 230bar**

* Extrapolated afterwards, checked at the time but not written down

** The slight change in this tank would be due to using it for wing/drysuit inflation

The Nomad LTZ Harness/Wing about to begin what is probably going to be a hard, miserable and relatively short life, but with much excitement.
The Nomad LTZ Harness/Wing about to begin what is probably going to be a hard, miserable and relatively short life, but with much excitement.

Narrative of the Final Dive

Arriving at the sump, there was the usual dance of trying to get changed from filthy wet trogsuit into dry undersuit and drysuit, without getting too much mud on the zip. (all this on a small mud/sandbank with about 1.4m vertical space) With plenty of willing hands to make the process quicker, I was promptly geared up and face down in the mud, wriggling out into water deep enough to float in.

It wasn’t too much of a drama getting through the first long and flat restriction with the 3rd tank, in fact having it unclipped was a pain and it was much easier leaving it clipped for the way back. I made good time and popped up into the small chamber at the end of sump 1, crawled across the couple of muddy metres and continued into sump 2. The line was pleasantly still in the same condition (excellent?!) that I’d left it and didn’t need much tidying up.

Vis seemed to be a slight improvement on last time at 3-4m, and pretty soon the reel was unspooling into new cave (after noting gas pressures), with the nice “She Goes Tunnel” going straight ahead.

The profile was square, with a flat silty floor and weak rock or mud chunks on the walls that preferred to fall off rather than be tied off to. Siltpegs were used occasionally, but the straight tunnel allowed a good long distance between them. At regular points there were shallow air pockets on the ceiling, one big enough to stick my head up into.

The tunnel constricted ahead and I wondered if it would be a terminal rockpile, as there were rounded rocks about 10-30cm in diameter piled at the bottom of a slope in 3.5m water depth.

But no, although low and sloping up, I could happily fit through and after having some difficulty jamming a siltpeg in at the start of the slope, I followed the sloping restriction upwards. The gentle current had started to push some silt ahead of me, but I was relieved when the ceiling disappeared and I broke the surface into a nicely sized chamber. Actually, it was really pretty big, being about 30m long, 4m high and 3m wide!

This sort of diving is quite glamorous, especially if you enjoy lying face down in mud.
This sort of diving is quite glamorous, especially if you enjoy lying face down in mud.

Coming out of the water, the cave actually took a 90 degree turn to the right, in a high passage with a shallow lake and a beach that I was at. I took a moment to sunbathe, catch my breath and also make a solid couple of tie-offs and tie on an arrow pointing towards home.

It was interesting to note the little white cave bugs in the water, similar to the ones at the start of the Dreamtime sump. Checking my gas I still had heaps left for penetration, and if the cave kept on at this depth, it was going to be one seriously epic long dive and I would probably run out of line again!

But the cave had other ideas: after wading the “30m Long Lake” lake and sumping again, it dropped straight to 12m. Ok, that was fine, I still had plenty of gas for that … But over the next 200m (and tying in the third reel!) the passage continued to slope down in regular steps (with low sections, but nothing too bad) before it bottomed out at 26m.

Getting towards turn pressure, at 25m+ depth and with only 9l tanks (also by this point a good hour away from the support crew) there were definitely some mind games going on. I reckon being on edge at times like these is a very useful survival mechanism! Confidence in your planning also helps.

Having a bit of penetration gas remaining, a conservative plan and an airspace not too far back, I pushed on … and the cave came up! Up a series of steep slopes with some tight/flat bits, with a few clumps of silt rolling down, until the cave turned into more of a rift passage in 5m water depth.

It was showing all the signs of surfacing again (into fabled gigantic master cave?), and with not much penetration gas left I followed the ceiling, eventually reaching a tantalising 1m water depth but with no cigar, and no surface either.

The rift passage looked high as I couldn’t see the bottom, and it didn’t seem to be going all the way to airspace, although it was certainly going on ahead.

With turn pressure reached and my 7l steel tank now basically empty I reluctantly wound in 10m or so of line to find a final tie-off point, having well and truly used all the silt pegs.

With the reel clipped off and wetnotes out it felt good to be heading home, even though it was a cold, long way which all had to be surveyed (what so-called responsible explorers do).

This helped keep me focused and the gentle current made for a nice swim back in relatively good visisibilty compared to most sump exits, due to the percolation of silt off the ceiling from exhaust bubbles. Turns out I’d added 350m of new line, and surveyed 500m in that dive, a pretty good effort! (Mind you, considering the 85 person-hours of in-cave time contributed by the team, perhaps this is debatable)

As usual, I was told unceremoniously to hurry up and get changed so we could get out of there. This may seem unfair to the non-caver, but the reality is that I was dry, warm(ish) and doing exciting stuff, while the others had been sitting in the mud, in damp muddy clothes, in a cave with ambient temperature 10°C, for the best part of an hour and a half with only the occasional hot drink or Dave & Sandy domestic argument for entertainment.

The idea of cooking up some of the abundant aquatic cave fauna was also floated (pun intended) but discarded.

After a dive in 8degC water, it's always comforting to know you have something warm and comfortable to change into.
After a dive in 8degC water, it’s always comforting to know you have something warm and comfortable to change into.


Before the considered faffing which is a prerequisite to getting packed up and moving again we had a quick council of war and decided to bring all the tanks out – this was sad, but it was felt that for the effort involved to go much further, the next push would need a different approach that wouldn’t be happening before winter. However, we left all the weights (no belts or rigging) tied to a protrusion on wall, back from the sump in the larger passage. Hopefully they survive the winter floods.

Alan plotted the survey data the next day and the sump has surprised us – rather than heading for upstream of Niggly and projected master cave beyond the terminal (upstream) Niggly rockpile, it is heading for the downstream section (and only 200m away) right where there is a record of a stream entering through rockpile.

With key personnel unavailable, an attempt at making the connection is going to have to wait until next summer, and plans of attack are under discussion: stay posted for the next instalment.

Thanks and Acknowledgements

The usual thanks go to Andreas for generally organising pretty much everything, Liz for taking photos even when no-one else was motivated, Alan for mapping and generally being a JF guru and everyone who carried gear or did setup trips. This sort of thing is not done so someone can have a fun dive – it’s to carry out meaningful exploration and bring back data with purpose. I’m glad we as a team could achieve this.

It is a great privilege being the push diver, but the whole thing is so much a team effort that the efforts of the push divers are tiny in comparison to the efforts of the rest of the team that makes it all possible. Thus, thanks need to go to all team members who made the underwater extension of the cave possible:

  • Andreas Klocker
  • Stephen Fordyce
  • David Bardi
  • Sandy Varin
  • Alan Jackson
  • Liz Rogers
  • Dan Haley
  • Michael “Pax” Packer
  • Ken Murrey
  • David Taberner
  • Did I miss anyone??? (ie. from Andreas’ dive?)
It's a well-known fact that the bigger your headlight, the more line gets laid and the less gas used (yes, that gauge says 180bar!). As I keep reminding everyone, the next light will be much smaller dammit! Update: My current light, the ElkLight MkIII, is a vast improvement.
It’s a well-known fact that the bigger your headlight, the more line gets laid and the less gas used (yes, that gauge says 180bar!). As I keep reminding everyone, the next light will be much smaller dammit! Update: My current light, the ElkLight MkIII, is a vast improvement.

Meet Stephen Fordyce

Stephen Fordyce is an active cave diver, sump diver and caver, and veteran of exploration projects in Australia and, on occasion, further afield.

Stephen is a keen ocean diver as well as being an engineer and inventor (the "ElkLight" caving lamp being a prime example).

With a background in design and manufacture for the industrial gas sector, Stephen combines his passion for technical diving and cave exploration with his lifelong love of making cool stuff via TFM Engineering Australia.

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