This week at Mawson: 11 August 2017
This week we are learn about the machine that reigns supreme in Antarctica; and where every precious drop of our fresh water supply comes from…
For the love of Hägglunds
Here in Antarctica there is but one machine that reigns supreme. The Hägglunds BV206 (affectionately known as a Hägg).
First designed by Hägglunds in the late 1970s, with production commencing at the start of 1980, over 11,000 units have been made with most sold for military applications.
The Australian Antarctic Division has been utilising them for many decades now, they have stood the test of time and have come a long way since the days of the old 5 cylinder Mercedes models.
The Antarctic Division has invested thousands of hours over the years into refining, upgrading and modifying this workhorse into the sophisticated machine used today. This has only been possible by the very talented and dedicated mechanical team at Kingston.
The Hägglunds is one of the most versatile machines used on station, there are three main variants used: SAR, firefighting and general purpose.
Under the hood is a Cummins QSB4.5 Turbo Diesel mated to an Allison transmission. Steering is made possible by a very ingenious from of articulation between the front and rear cabs. With a range of up to 250 km between refuelling, a wide footprint and plenty of power, the Hägglunds is most at home down here in Antarctica.
The four occupants of a Hägg needn’t be worried about the freezing temperatures outside, with one very large top mounted heater and floor mounted heaters to keep the cab warm and toasty. Visibility is taken care of by two large LED flood lights, GPS navigation with radar and a heated windscreen.
Did I mention they are amphibious as well?? They have a top speed in water of 4 km/h – not bad for a machine that weighs over 4 tonne with no propeller. Häggs can be loaded with 2250 kg and tow 2000 kg!
The Hägglunds is a machine that cannot be praised enough. I wish I could take one home, but with a value of nearly $500,000 I don’t think that is going to happen anytime soon.
Anyway talk soon
Every precious drop
Antarctica holds 70% of the world’s fresh water and 90% of the world’s ice, so you’d think Mawson would have no problems with its water supply, but being on the driest continent on earth does raise some special challenges.
All of our water down here is in a solid form which is really only good for keeping your drinks cold. As a plumber on station one of our daily tasks is to make sure our water storage tanks are full and in liquid form. Our water down here is sourced from a melt well. To do this we use a Rodriguez Melt Bell. There would only be a few people in the world who would have any idea about what I’m talking about and even fewer who have ever used one.
The simple explanation is that the melt bell is a sealed metal tank that has an inlet and outlet on the top and a pump on the inside. The bell is placed in a small hole in the ice and hot water is circulated through it 24 hours a day which makes it hot and starts melting the ice around it. When there is enough melted water around the bell we pump it out to our water storage tanks.
The bell has hoses connected to it and is attached to pontoon with a winch so it doesn’t just disappear into the depths of Antarctica. As the bell melts it way down through the ice it creates a 'well' of water for us to draw from. Our current well is about 10 metres deep with a shaft about 2 metres wide which opens up to be a 5 metre wide cavern at the bottom.
Each day we are able to draw off enough melted water to keep the station running and keep us clean and hydrated. We need about 2000 litres per day.
The water tanks are kept in their own heated building so that our supply doesn’t freeze. The water is then pumped in a circuit around the whole station in heated, insulated pipes so it doesn’t freeze. So when we drink a glass of water down here or have a shower we are mindful of the how precious water is, even though we have most of the world’s supply right on our doorstep.
Until next time,