Motors: 600 metres below the ice

Jon Lawson

Anja Schütz presents a cool case study involving innovative motor technology

The kilometre thick ice of the Antarctic holds many secrets. For decades, scientists have researched the history of global climate by ice-core drilling.

One such team is the research organisation British Antarctic Survey (BAS). With a new technology the researchers can drill eight times faster in to the ice.

The British organisation has five research stations  in the Antarctic, five aircraft, two research ships and a multitude of scientists who do research in the perpetual ice. BAS is the world’s leading centre for polar research and expertise, addressing issues of global importance.

The Ice Dynamics and Palaeoclimate Team developed a new technology, rapid access isotope drill (RAID), for ice-core drilling. The technology makes it possible to penetrate much quicker into the ice. Conventional ice-core drilling takes a long time. For example, the 3.4km deep hole at Dome Concordia in the eastern Antarctic took five years to complete. 800,000 year-old ice was retrieved; until now the deepest insight into the history of the Earth’s atmosphere.

However, sometimes ice-cores from such deep holes do not produce good results, ie if the ice-core has been taken from the wrong place, according to Julius Rix, ice core drilling engineer at BAS.

Robert Mulvaney, scientific leader of the research team, states that before drilling a deep ice-core it will be possible to use the new technology to drill several small cores of approximately 600m depth, and bring them to the surface for analysis.

Drilling to this depth takes about seven days; with conventional drilling two months. The thickness of the ice and the geothermal heat indicate if it is worth drilling deeper. “It’s all very exciting as nobody before has tried to drill holes in the ice of the Antarctic so quickly,” declares Mulvaney enthusiastically.

Standard product in the Antarctic

“It proved difficult to find a powerful small motor for our application,” says Rix.

Therefore BAS asked maxon motor UK about a strong motor with high torque. It should be able to vary the speed of the drive at a constant torque.

One prerequisite was also the size – the smaller, the better – as the drive must fit into the relatively small drill, keeping in mind the harsh environmental conditions that the drive system has to withstand.

The maxon engineers recommended the maxon EC 45 with 250W and a GP 52 planetary gear. A standard product!

The first drilling tests showed that the standard product could withstand the high vibrations and low temperatures. Only some small modifications were required. “maxon really helped us with selecting the right motor and making test motors available to us in advance,” states Rix.  

Anja Schütz is with maxon.   

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