SARAH GILBERT and TONY VENESS STC | During the summers of 2013 and 2014, week-long expeditions were run once again as part of the ongoing Exit Cave Mapping Project at Ida Bay in Southern Tasmania.
STC, in conjunction with the Tasmanian Government Department of Primary Industries, Parks, Water and Environment (DPIPWE), organised these third and fourth summers of surveying and sketching.
A comfortable base camp was established outside the Exit Cave resurgence to support the main periods of work.
This article details the achievements of the 2013 and 2014 expedition seasons. Readers are referred to CA Issue 189 (PDF) for background to this project and the surveying protocols developed.
The overall project aim is to survey the known passages of the Exit Cave system to ASF 5.4 using modern survey equipment and practices, whilst incorporating as many existing datasets as possible.
Multiple generations of survey markers exist throughout the cave system but often little survey data remains from these previous survey trips.
Using modern technology, we have created an electronic archive for use by future surveyors. Cave surveyors in 50 years’ time will no doubt see our efforts as antiquated and will want to resurvey it again using their latest and greatest technology. Such is life.
E2013 was a much smaller and less international expedition than the 2012 expedition and 14 cavers from STC and Northern Caverneers answered the call-to-arms (well, in reality a call to sketchbooks and instruments).
The hardy few—Tony Veness, Geoff Wise, David Butler and Sarah Gilbert—stayed the whole week whilst others joined us as time allowed.
During the weekend before the main event we carried much of the communal gear to IB-14 via a 90-minute walk through the rainforest from the car park. We re-established Camp Gumboot at the main resurgence entrance to Exit Cave (IB-14) as in previous years.
To sighs of relief from some, the additional smaller Camp Dairy Boot (aka Camp Misery) at Valley Entrance (IB-120) used in 2012 was not re-established, due to the smaller survey party numbers.
Our base camp, with its essential mosquito shelter, under-cover communal cooking area, pit toilet and natural cold water bathroom was more than adequate. This year’s pre-expedition organisation was simplified with everyone self-catering for meals, although the group supply of cooking gas bought in 2012 will last us a few more years yet.
The surveying and record-keeping protocols were already in place, tried and tested. This year’s focus was to sketch areas surveyed in 2012 and to continue surveying and sketching the numerous side extensions. For areas to be sketched to scale, we used pre-printed sketch sheets which displayed all existing shot data.
This enabled small teams of sketchers to work in one area while another group of more active cavers collected shot data nearby. This approach was designed to keep everyone happy.
Sketchers were able to take the time required while other team members were active and productive rather than sitting around waiting in the cold.
Highlights and achievements 2013
• We completed the re-surveying and re-sketching of Conference Concourse in the far north-eastern region of the cave system. This was in very good agreement with the original 1971 survey with the addition of several side passages and loop closures. The agreement is a testament to the 1971 team who worked without the luxury of equipment from companies such as Leica, Scurion and Petzl.
• The discovery of the wet and crawly passage Hard Mans Way (otherwise known as Where Hard Men Weep). This rather unenticing passage leads towards the hydrological connection between Conference Concourse and the streamway north of the Grand Fissure.
Unfortunately, it ends in a large rockfall chamber similar to all the other passages leading towards this region—the mysteries of where the water flows through the Bermuda Triangle remain for a small, agile caver of the future.
Inevitably, while finishing a small job on the afternoon on the final day we rediscovered an additional side passage in Dribble Loop to be sketched and surveyed. It was well worth it though, as the impressive 50 m plus high double aven of the Devils Stovepipes was visited for the first time in many years and linked into contemporary survey stations.
• In conjunction with the main E2013 expedition Janine McKinnon and others pushed the D’Entrecasteaux River sump in February 2013. Their cave diving exploration is outlined in more detail in Janine’s previous Caves Australia article CA Issue 196 (PDF).
The format for this year’s work was slightly different to previous years. E2014 was held over two five-day extra-long weekends in February and March 2014. This allowed more flexibility and time for people to recover between rounds. There were only nine cavers this year with the dogged main crew and a few new faces continuing the five-year-long battle
The expedition was run similarly to E2013, with base camp at the IB-14 resurgence. On the first day, with the welcome help of a few additional hands, we carried all our personal, communal and surveying gear over Marble Hill and set up Camp Gumboot once again.
We strung up tarpaulins, constructed tables, set up the essential mosquito shelter and dug the pit loo. With our now well-practised team, camp was set up quickly with enough time for some cave sightseeing and survey equipment organisation before dinner.
E2014 was planned to be the final expedition of the five-year-long project. The aims of this year’s expedition were focused primarily on finishing the sketching of the main passageways and extensions, and exploring and tying in several loop closures, if they existed …
Highlights and achievements 2014:
• Surveying the loop closure at the southern end of Conference Concourse; connecting two separate surveys from 2012 and 2013. This ended up requiring one survey leg which was only 20 m and one year apart. Another potential connection from Conference Concourse towards Hard Mans Way remains elusive, ending in a very fresh and unstable breakdown chamber. Surveying of this connection has been left to future younger, bolder and smaller cavers.
•The survey and sketching of the Eastern Passage extension was almost completed using some of the existing data from 2005 and by resurveying and sketching the remainder. A return trip will be needed next year as our surveying was halted by a lack of rope at a 10 m pitch in an otherwise horizontal extension. The previous survey data for this area continues for another few hundred metres, so it will be well worth returning for.
• Finishing the sketching around the Mini Martin entrance (IB-8) and Inner Base Camp chamber. This work ties in the previous surveys of Western Passage, Dribble Loop and the main streamway.
• Final decommissioning of Camp Gumboot. Some of our equipment had remained in the bush for the previous four years, no worse for wear. Thankfully, with the recruitment of a few additional Sherpas, we were able to carry everything out back over Marble Hill and on to the car park in one load.
Nearly all the in-cave surveying and sketching has been completed in this impressively large cave system over the past five years. A few jobs still remain, however:
• Replacing the old, deteriorating track marking through the well decorated sections of the Ball Room and Eastern Grand Fissure extensions.
• Many hours of computer time to digitally sketch all of the survey data from 2012-14 onto several overlapping A0 map sheets at 1:1000.
• Several weekend trips in summer 2014/2015 to ground truth digital surveys, if required and to finish the Eastern Passage sketching.
• To photo-document the main survey stations and remove temporary flagging tape survey markers placed over the last five years.
• Production of the ‘final’ Exit Cave map.
This project has been a massive joint effort over five years and is the culmination of many long, cold days of hard work. Thank you to all those who have contributed to the exploration, surveying and mapping of Exit Cave throughout the current project and over the past 40 years.
STC would like to thank the following organisations for financial or logistical support of the Exit Cave Survey program over the past five years:
• Department of Primary Industries, Parks, Water and Environment, Tasmanian State Government
• Parks and Wildlife Service Tasmania, Tasmanian State Government
• ASF Grants Commission, Conservation and Environmental Grant
• WILDCARE Inc. Karstcare program grant
• Department of Sport and Recreation’s Minor Grants Program, Tasmanian State Government
McKinnon, Janine 2014 ‘Exit Cave, Tasmania. D’Entrecasteaux River Sumps exploration 2013’. Caves Australia
Veness, Tony 2012 ‘Exitravaganza 2012’. Caves Australia 189: 8-11