This article is inspired by Yuri Pasholok's article on the same matter. When we say WW2 and Antarctic, many people will immediately start thinking about crazy theories about nazis secret bases under the ice, experimental weapons and whatnot. This is naturally a nonsense (hopefully), but the topic is not that far from the truth. Between 1939 and 1941, the Americans actually sent an armed expedition to the Antarctic, called United States Antarctic Service (also known as Third Byrd's Expedition). The unit was led by a former polar explorer, Admiral Richard Byrd, consisted of 59 men and some equipment, transported to the Antarctic by ships. It was an exploratory expedition, charting previously unknown coastlines for over two years. Now, that is all well and good but what makes it really interesting is this:

That's right, those are two tanks, specifically three M2A2 Light Tanks (two of them are on the photo) and to this day they are the only two tanks to ever serve in the Antarctic. There were two bases founded during the expedition - East and West - and both were evacuated in 1941 as a result of the wartime tensions (Richard Byrd left earlier, the expedition continued to operate for some time without them). The tanks never fired a shot in anger and were left behind. Interestingly enough, Yuri Pasholok managed to find a Russian report in the archives, describing the entire operation, as it was disclosed to the USSR military liaison in the US, Major Baraev.
Here are some points from the report itself:

- the tanks were too heavy to operate on the snowy surface, that's why it was decided to first remove the armament and pieces of the armor from them and later on the entire turrets, the tanks served to actually tow things (tractors);
- thus, the ground pressure was brought to 5 or 6 pounds per square inch, which was still a bit much, as 4 pounds per square inch seems ideal for that kind of terrain;
- additional grousers were welded to the tracks to increase the traction in snowy terrain;
- the snow, flying from the tracks, was blocking the vision of the driver, this was fixed by installing some sort of shield for the driver;
- carburators in the engine were working fine, they didn't stop working, but there was an issue with water getting into the gasoline and the Russian Major proposed to counter this by filtering the fuel via some sort of mesh (he mentions suede cloth);
- one of the reasons why the fuel pipes didn't freeze was that they were actually warmed by the engine heat;
- the batteries worked fine, but there were issues with the air filters in the engines, which did freeze. Same issues plagued the oil filter, causing the oil itself to congeal in it, resulting in the recommendation to remove it altogether from the vehicle, as it is not needed in the Antarctic anyway;
- finally, the engines had to be equipped with heaters, that pre-heated the oil and the engine itself to 50 degrees Fahrenheit (10 degrees Celsius), the motion of the tank was however only possible when the engine temperature reached at least 37 degrees Celsius.