July 2005

Pete's Post from Antarctica - July 2005

As I write this, it is mid June. The shortest day of the year is only a week away and we'll celebrate with a mid-winter party and a polar plunge. It is now dark all the time, but in the middle of the day there's still a faint blue colour in the sky and a red glow on the horizon to the north. It is also getting colder, so I'll make a few observations about "cold".

When I first arrived here in October, I thought that -15degC was pretty cold. Now I'd call it a warm day. The difference is partly explained by acclimatising to the temperature. But we've also learned to manage the clothing systems to stay warm. We were issued with a mountain of clothing,and each of us needed to work out which garments and gloves provide the best balance between insulation from the outside temperature and preventing sweating inside the clothing. My customary outer layer is a one-piece insulated suit that we call a bunny suit. It is really a garment designed for people who work in freezers. Most other staff wear Fairydown down-insulated jackets and salopettes, or insulated canvas garments made by the Carhutt company in America - these are very good..

We are given polypro neck gaiters that can be pulled up around the face, as well as a balaclava. My usual head covering is a beanie hat plus an American ski mask that looks like something Hannibal Lector would wear. I find this provides enough protection for exposed skin on my face whilst still allowing me to breathe without my goggles fogging up. The polypro neck gaiters retain the exhaled air too close to the face, and most people who wear them experience the goggle-fogging problem.

Yesterday I was working outside on the Ross Ice Shelf about 40 minutes drive from the base. There was no wind, and the temperature was minus 40. The air was full of tiny ice crystals that sparkled in the light from the vehicle, or my head torch. Despite the air temperature, I was toasty warm in my bunny suit, and ski mask. I had two layers of clothes under the bunny suit, and wore polypro liner gloves and leather work gloves. I also carried thick insulated mittens with chemical heat pads inside them, but didn't need to use them. If the wind had been blowing more than a few knots, I would have felt the cold. Windchill is the big killer, not the ambient air temperature.

At minus 40, the vehicles take twenty minutes to warm up. We drive Toyota Landcruisers that are fitted with an electrical heater in the block. When we park the vehicle, we plug it in to an extension cord at our "hitching rail" and this keeps the engine temperature warm enough to ensure we can start it. There's also an electric fan heater in the cab, controlled by a thermostat.
The cabin temperature when we first get into the vehicle is usually nice and warm at about freezing point.

At minus 40, the gearbox oil is very thick and sluggish. It is difficult to change gears until it warms up. The hydraulic fluid also thickens in the cold, and when you release the clutch it takes two or three seconds for the pedal to come back up. This makes it interesting to do a hill start !! The low temperatures are hard on the fanbelts, and they often break. Each vehicle is fitted with dual fanbelts.

Cold air cannot hold much moisture, and the humidity very low - even inside the base. The dry air allows static electricity to build up, and every time you touch something metallic a spark jumps from your hand. We learn to regularly touch the metal walls or framework as we walk around the base to discharge ourselves before the charge builds up too much.

The dry air also dehydrates you. We need to drink much more liquid (including beer ???) than we do in NZ.

The texture of the snow is very dry and fine. When the wind is blowing, the drifting snow looks almost like smoke wafting across the surface of the road.

Last week the temperature reached -48degC. At these temperatures you can take a cup of boiling water and throw it up into the air, where it freezes instantly and falls back as a powdery shower of ice crystals. Interestingly enough, if you try this with cols water it doesn't freeze, but falls back to the ground as liquid. Perhaps someone would like to explain the physics behind this - surely hot water needs to become cold water before it can freeze?

Some days there is a temperature differential of sixty degrees or more between the outside air and the interior of the base. You notice this when you stand in a doorway and feel the heat racing out past you. All our heating energy comes from the diesel generators and boilers, so we have to be careful not to leave the doors open too long.

Pete de Joux from Antarctic

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