Climate change, its effect on CO2, on the world's weather and the future of our planet, is a subject of great discussion; but how do you measure the atmosphere from thousands of years ago? Using Maxon Motors British Antarctic Survey plans to look further than ever before.
Scientists at British Antarctic Survey (BAS) have been working on discovering how the climate has changed over many thousands of years by drilling holes in one of the most untouched landscapes on the planet. The Cambridge-based scientific research centre has a long history of research in Antarctica, and is preparing for a project to attempt to collect, for the first time, climate data from a million years ago. By drilling down to great depths they are able to extract ice formed many years ago. Analysis of the ice allows the scientists to look back through history at the various ice age cycles and the effect of human CO2 pollution.
BAS have typically used large 5-inch drills with a hollow core to collect ice core samples. It can take many months to drill down to depths of up to 3km and, as this work is only able to be carried out during the Antarctica summer months, it can take many years to complete. The correct selection of the drilling site is essential. Six test sites have now been identified and, in November 2015, BAS will spend 6 weeks drilling test bores, down to 650m, to select the next location most suitable to find million-year-old ice. They will be using a new drill with a smaller diameter (3 inch) that will speed up the process, as they will collect drill chippings rather than an ice core for analysis. The climate modellers can then determine the best location.
BAS contacted Maxon Motor UK with a requirement for a powerful motor with high torque in a small diameter to fit in the drill. They needed to be able to vary the speed and get constant torque even at a slow speed, yet still be able to get the maximum torque. Paul Williams, Senior Sales Engineer, from Maxon Motor comments: "For the prototype I suggested a standard off-the-shelf maxon brushless DC 45mm 250 W motor - we changed the casing (from square to round) in order for it to fit into the tube - and a GP52 planetary gearhead. My expectation was to modify this for use in the field with a product from our Heavy Duty range to manage the high vibration, low temperature and high efficiency required for this type of application; but the off-the-shelf combination has proved to be more than capable. We have not even needed to change the lubricant even at the extreme temperatures the drill is exposed to".
The frozen continent presents an extremely harsh environment especially on the high plateau in the interior where BAS are intending to drill. In these locations the average annual surface temperature is close to -55degC. Research teams visit during the polar summer when temperatures barely rise above -20degC. As the drilling commences the temperature rises; at 600m deep it is -50degC and at 3km down it is at -5degC, which is melting temperature. Unfortunately, once the ice at the bottom of the core has melted the data is lost, which is what happened at Dome C over a decade ago and that limited the data age to 800,000 years.
Julius Rix, a drilling engineer with BAS, states: "Maxon Motors do what they say on the tin. They have good specifications and are reliable in tough conditions so we were quickly able to test what we needed. From sediment records we know that in the past it was warmer and we think that the planet will get warmer in the future. With this research we can be more confident of what the effects of climate change are and how to react to them".
To learn more about motors from the company, please visit www.maxonmotor.co.uk.