Navigation on Amundsen’s South Pole Expedition

There was an interesting article in Navigation News recently, The Long Journey Home, which looked at Amundsen’s navigation techniques on his South Pole expedition.

The author, Christopher Sweetman, draws attention to Amundsen’s use of compasses, meter-wheels fixed to sledges and the sextant. But of more interest to natural navigators were his use of pace-counting and his disciplined habit of building snow beacons, every three miles from 82 degrees south onwards.

“On the following day we were already in sight of the large pressure-ridges on the east, which we had seen for the first time on the second depot journey between 81° and 82° S., and this showed that the atmosphere must be very clear. We could not see any greater number than the first time, however.

From our experience of beacons built of snow, we could see that if we built such beacons now, on our way south, they would be splendid marks for our return journey; we therefore decided to adopt this system of landmarks to the greatest possible extent.

We built in all 150 beacons, 6 feet high, and used in their construction 9,000 blocks, cut out of the snow with specially large snow-knives. In each of them was deposited a paper, giving the number and position of the beacon, and indicating the distance and the direction to be taken to reach the next beacon to the north.

It may appear that my prudence was exaggerated, but it always seemed to me that one could not be too careful on this endless, uniform surface. If we lost our way here, it would be difficult enough to reach home.”

From Amundsen, Chapter X: The Start for the Pole.

Natural navigators will notice many interesting things in the passage above.

Firstly, the technique of building these beacons may appear exotic in the context of a pioneering push for the Pole, but it is actually a common-sense technique from a wide family of such methods used since pre-history.

‘Blazing a trail’ or ‘way marking’ – for example: building stone cairns, lighting fires, cutting or bending trees, marking the ground, laying crumbs in the wood (possibly the most famous, but not the most reliable method 🙂 – is a way of ensuring that the journey home does not have to be as hard as the route out. Why struggle to retrace a route, when it can be made as easy as joining the dots?

It is also worth noting that, in the first paragraph, Amundsen is finely tuned to the importance of landmarks, even impermanent ones, like pressure ridges. He also uses these landmarks to assess visibility, which all polar travels are sensitive to, not least as everywhere on earth it can help predict deteriorating weather.