A Rough Ride in a Caterpillar Tractor
I am acclimatized, my equipment is unpacked and functioning, we all arrived safely. Now its time to get to work. This year I have brought with me a prototype of a new version of the Aethalometer, that performs its measurement both with visible light (to detect black particles) as well as with ultraviolet light. Some chemical species absorb very strongly in the UV, although they are not visibly black components of tobacco smoke, for example, diesel emissions, and perhaps (aha!) some of the organic species in aircraft engine exhaust.
While other arrangements are being finalized, we set up the UV-Aeth in the upper galley room, a small social area next to the door to the bar. The bar is the only room on the station where smoking is allowed, and the door has a spring closer. Sure enough, when I look at the data the next day, there are some rapid increases in the UV measurement, with relatively few accompanying black particles, that probably indicate people opening the bar door and allowing cigarette smoke to escape. However, there are also fairly long periods showing high concentrations of UV absorption as well as proportional amounts of black carbon. This looks a lot like a diesel-exhaust "signature". The bar and upper galley room are somewhat ventilated from the outside the outside being the interior of the Dome, into which tractors drive from time to time, bringing in pallets of freight. Whenever this happens, the inside of the Dome fills with diesel fumes, and, of course, some of those fumes will find their way into the enclosed spaces of the buildings. While the scientific evidence is neither novel nor overwhelming, it confirms that the UV-Aeth is working correctly, and that tobacco smoke and diesel fumes here have the expected characteristics.
The real fun, though, is yet to come .. measuring the exposure of the cargo crews to aircraft exhaust.
We are going to use 2 Aethalometers: one conventional one (black carbon only) will ride with me in a vehicle, and we will park directly behind the aircraft to get a measure of the BC concentrations in the air right behind the plane. The other one, the combination UV-BC, will be mounted in the cab of a caterpillar tractor with its inlet above the head of the driver. This will register the particle concentrations in the tractor cab as it drives back and forth behind the aircraft, maneuvering the loads on and off the plane.
One of the Snow-Cats is available, so it is assigned to me, Im shown how to drive it, and we load one Aethalometer into the back seat on a cushion. I had brought a power inverter which we clipped to the battery, and all is well and functioning. The Snow-Cat is fun to drive, but a little bouncy.
The other installation was a lot more daunting: not from the perspective of being difficult, but simply the concept of lashing a sensitive, ten-thousand-dollar item of scientific instrumentation into a snorting, oily Caterpillar Tractor, most of whose visible parts were made out of solid steel at least an inch thick. They drive the Cat into the garage: it clanks in on snowy iron feet and belches its exhaust into the confined space, a Dragon of medieval horrors.
The second power inverter is hooked up, and I carefully hand up the UV-Aeth, wrapped in a cocoon of foam rubber pieces held together with duct tape. We wrap a packing blanket around it and then literally lash it in with ropes. Embedded computer ! Sensitive opto-electronics !! tiny UV lamps !!! a highly-sensitive prototype scientific instrument, sent to war in a tank, lashed in with oily ropes.
The power works, the instrument works, there are no further excuses or delays. The Cat blows a huge cloud of exhaust and clanks out through the doors, lurching and swaying. I almost feel like closing my eyes, expecting to see a trail of tiny Aethalometer crumbs left on the ground-up snow.
The driver is a woman of my age, who is an artist back home. She had been a cook down here, 3 seasons ago, and wanted to return but in an outside occupation. They offered her a job as a cargo handler if she would get some training as a Caterpillar tractor driver. She took the training, and is now grasping iron levers with gloved hands, instead of a paintbrush.
The plane arrives, and we go into action. Its really bad where I am, in the Snow-Cat under the tail of the plane, on the far side away from Cargo-Ops. The blast from the propellers rocks my vehicle, the noise is deafening, the exhaust fumes are really bad. From my vantage point, I see the Instrumented Cat approach, bearing gifts with outstretched arms in the form of a cargo pallet loaded with a Giant Spool, going home. As I watch, almost immobile from horror, the Cat, its load and !!! My Beautiful Instrument !!! lurch and sway and crash back and forth as the tracks grind up the snow during maneuvering. I cannot believe that anything that works on the principle of making tiny, fine determinations of the change in optical properties of a little spot of tape, to a precision of 1 part in 10,000, can possibly survive this tumble-drier.
Aethalometer in bundle behind driver
Amazingly, it does survive .. and very well too. Afterwards, we will find that the data from the tractor cab matches PERFECTLY with my measurements of the concentration being emitted by the engines. The concentrations in the tractor cab rise and fall, as the driver approaches the plane and then backs off to the staging area on the side. Amazing. Truly Amazing. The instrument worked, and worked well. As it turned out, we got data from 5 different planes, and found that their emissions varied a great deal, i.e. some planes were dirtier than others. The graphs showed that the concentrations in the tractor cab could be held to moderately low levels by keeping the door closed, and moving in quickly from the clean-air zones at the sides to minimize the time spent right behind the plane. Commonsense stuff, but now confirmed by 2 sets of scientific data.
But theres more for me to do. Several flights today. We also want to record the details of the tractors movements, and for various reasons Im delayed so that I have to rush out to the flight line just as the plane arrives, without having time to go back to my Tat and get extra clothing i.e. insulated overalls. Im lucky, I catch a ride over to the flight line on a sled towed by a passing snowmobile.
You guessed. Im gonna stand still with a clipboard for three-quarters of an hour in 42 degrees with insufficient clothing.
Gordon Bennett ! (a quaint British expletive) I get cold. I freeze, my glasses get covered with ice and I cant see my wristwatch, my goggles ice over, my pen freezes so it wont write unless I unzip my coat to put it under my arm, and that lets in more cold air, I cant wear my thick gloves because then I cant hold the pen, you get the idea. Gordon Blooming Bennett. Gordon Blooming Frozen Bennett.
But there is one moment of inspiration in this frigid idiocy titled Clipboard-With-Icicles. Around me are the various ground-operations crew, taking care of things like the aircraft fuel, the passenger checklist, etc. At Pole, men and women share almost all tasks equally. Todays Ground-Op is a woman, dressed to manhandle (womanhandle?) fuel hoses and packing cases and whatever, dressed as a Working Polie in insulated brown coveralls, quilted jacket etc. But lacking the bushy beard of most of the Outside-Tasked men here, she has pulled her neck gaiter up, way over the nose, to keep her lower face warm. Her hat is pulled down to keep her forehead warm. The eyes show through a narrow slit in this mass of clothing, eyes framed with the only skin visible.
The visual effect is stunning in its incongruity. It reminds me of the Islamic veiling of women. Its the image we see from Tehran or Kabul .. except for the oil-stained coveralls and the giant boots. The chador has reached the Industrial South Pole.
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Prepared by Tony Hansen, Garry Rose and Paul Babushkin. Last edited 6 Feb. 1998