“ humbles the soul. Underground I find myself doing things that are unimaginable topside,” says Mark S. Cosslett, adventurer and photographer.

26 163/2003 Mark S. Cosslett Photographer/Adventurer IntoAdventure Canmore, Alberta Canada

Reaching Uncharted with the Aid of Accurate Carbon Dioxide Measurement

What started as a faint vision nearly five years ago became a reality for our team of three cavers from Canmore, Alberta last January. The landscape of Northwest- ern Thailand holds vast treasures of uncharted passages, many of which, howev- er, are guarded by high concentrations of carbon dioxide. It was the nemesis of my previous expedition back in ’98 to explore new cave passages: our team invariably got turned around by carbon dioxide. After a lot of research into bad air in caves, we set out to Thailand better equipped this time, carrying lightweight oxygen bottles and a Vaisala CARBOCAP® Hand-Held Carbon Dioxide Meter GM70.

arbon dioxide (CO2) is a made us turn back, happy to deadly gas in high con- reach the surface alive. C centrations, which dis- places oxygen and results in rap- If you get into bad air, id asphyxiation. When entering you turn around uncharted passages, high carbon Upon returning home from our dioxide concentrations are one ’98 expedition, all I could think of the risks that cavers face, since about was what was around that an elevated CO2 level can also next corner in the depths of impair one’s judgment. Howev- Thailand. Within 24 hours of er, reliable methods to measure getting off the plane, I was at the CO2 on cave expeditions have library researching carbon diox- been scarce. An everyday butane ide in caves on the internet. I lighter is often used: incomplete found laborious research into or nonexistent combustion will the naked flame test in carbon indicate that the oxygen levels dioxide caves and unsuccessful are becoming dangerously low trails with heavy and cumber- (around 15% or less). “When the some scuba tanks, but no serious lighter goes out, get out,” was attempts to penetrate deep with my simple but life saving motto some sort of workable caving during our ’98 expedition. After breathing apparatus. All the ex- our team had already pushed perts on high concentrations of through a cave system, finding it CO2 in caves gave me the same to be the deepest in Thailand, answer: “If you get into bad air, fruitless sparks from the lighter you turn around.” I looked into “When the lighter goes out, get were the last thing I wanted to self contained breathing appara- out,” is the caver’s traditional life see, going into a cave passage at tus (SCBA) and equipment from saving motto when entering a depth of over 1,000 feet. But it the fire fighting industry ➤ uncharted cave passages.

163/2003 27 around, let alone a grants to find sponsors and (NGA) and National Geograph- The bats became singular again when rigid backpack. funding for a new try. ic Television (NGTV) staff who they hit us. First one Their supply of an were covering the project also on the arm, then on hour or two would Forgotten dream joined our team. Moreover, I the , then in not be enough for a revived was shooting still photography the face. full day or more un- Three years later, my project for NGA. derground. SCBAs nearly forgotten, I got a phone For product sponsorship, from the aviation call informing me that our Chinook Medical Gear came industry were a bit ‘Tham Pha Puek Caving Expedi- through with the high-altitude closer, but still not tion’ had been awarded the supplemental oxygen tanks, reg- workable. When Shipton/Tillman Grant of W.L. ulators, and valves; deli- chatting with a Gore and Associates. I asked for vered the caving equipment. As friend about how an extension from May to Janu- for a precision carbon dioxide the carbon dioxide ary, i.e. to the next dry season in meter, on which our lives would displaces oxygen, I Thailand, which is critical for literally depend, I knew Vaisala made an analogy to caving. With the good news, the had the best carbon dioxide me- the “thin air” found forgotten dream was revived and ter around and contacted Vaisala in high altitude planning began. My tests of sup- Inc. One phone call to Dick mountaineering and plemental oxygen theory in “bad Grönholm at Vaisala resolved realized that supple- air” caves in Texas with up to 7% the issue. “Your meter will be on mental oxygen is carbon dioxide showed that it its way tomorrow – just return it the answer. Small, worked. Next I put together the and let us know how things went lightweight tanks team of three – the most impor- when you get back,” was his easy used in moun- tant decision of all. The perfect response. taineering pursuits team members (Will Gadd and would provide an Maria Cashin) came from home Revisiting the cave 8–10 hour supply of in the small town of Canmore, A couple months later, I sat at which were far too cumbersome pure oxygen and be readily re- Alberta, where a large communi- the bottom of the world in Thai- for caving where you have to ne- filled at any hospital in Thai- ty of climbers, mountaineers, land, in the same place where I gotiate passages that you can land. After discovering this, I and adventurers is active. Na- had had to turn around back in barely fit your own flexible body submitted proposals for various tional Geographic Adventure ’98. At the corner that had be- come an obses- sion, we were all poised at the edge Our team found of the unknown. supplementary oxygen Our team hadn’t worked well to mitigate hit high levels of the effect of carbon CO2 the whole dioxide in caves, even if way down, and the system needs a great deal of refinement. everybody seemed to be breathing just fine. It seemed too easy. Strangely disap- pointed not to have the long- time adversary waiting there for me, I suggested taking a CO2 reading before go- ing further. Will thought that the air was fine, but I insisted on taking out the meter for a reading anyway. “It’s settling in… looks to be point five percent,” he

28 163/2003 said. As a connoisseur of lighter Studying carbon rocky river bottoms that tore the flames, I also pulled out my dioxide in caves dry bag. It finally succumbed to lighter which fired right up with our abuse when immersed in a a perfect flame. Both tools told The remaining two weeks of our dry bag full of water. The GM70, us that we could safely go for it, expedition were filled with look- which was so many things for us, and we started the long belly ing for CO2 in caves in order to met its specs by not being water- crawl. test our theories and equipment proof. and come back with useful infor- Many thanks to Dick Grön- An unforeseen obstacle mation which was one of the holm and everyone at Vaisala Around that corner lay a tight main reasons we got the grant in for helping to make our Thai- squeeze, then the cave opened the first place. It seemed ironic land caving expedition a reality. up into a big, easy cave passage to go looking for the very thing Look for the National Geo- again. We went at least another most people try to avoid, but we graphic Adventure article in 600 meters before hitting an un- found concentrations of up to their October issue and the Na- foreseen obstacle: bats, thou- 5% in several caves - plenty to tional Geographic Television sands of bats. You couldn’t think test our supplemental oxygen coverage. G of them as individual bats any- systems. We made more, but as a cloud constantly several observa- moving and swirling at the roof tions about bad air of the cave. Unfortunately, to caves, which are continue down the cave we had too detailed to to go up and over a hump and summarize here. into the terrifying cloud. The But overall we bats became singular again when came to two gen- they hit us, and would fall to the eral conclusions: ground stunned, flopping firstly, the supple- around miserably. We all freaked mental oxygen out and made funny, primal works well to miti- sounds at the bats whose sonar gate the effect of seemed out of order, and then carbon dioxide in ran back to the safety of the low- caves. Secondly, er river passage of the cave. We our oxygen delive- regrouped and decided not to let ry systems would the bats force us to return. In need a great deal single file, using our cave packs more refinement as shields, we pushed through before we would the “bat zone” to the safety of even consider put- the lower cave passage on the far ting ourselves in side. There our progress stopped situations where as the touched the our lives would floor of the cave. depend on them. Since there was a flow of The Vaisala fresh air and bats usually hang carbon dioxide out near the outside world, we meter became our desperately tried to find an exit, most trusted tool but to no avail. We found lots of to access the cave spiders, insects, and even a sur- environment in face dwelling frog during the our studies. It got precious hours we spent digging, dragged over probing and climbing in search rocky cave floors, of an exit. It was about not hav- through unthink- ing to go back through the “bat able mud, hauled zone” rather than about cave in cave packs up discovery. We finally gave up sheer rock walls, The Vaisala and, luckily, on the way out the and floated inside Carbon Dioxide bats didn’t bother us so much. dry bags in under- meter became our Either their sonar had improved, ground rivers. To- most trusted tool or our squeamish instincts had wards the end of for accessing the diminished, or probably a bit of our expedition, it cave environment both. got dragged over in our studies.

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