Electronics chilled to destruction in Arctic survey

'Make no mistake,' says Martin Hartley of the Catlin Arctic Survey 2010, 'if there's a fault in your equipment the cold will seek it out and find it.' By 'cold', Hartley means -40C and below, temperatures he's routinely battled with as part of the 'on ice' team of explorers with the survey, a scientific expedition that set out to collect data on causes of environmental concern such as ocean acidification.

'What you've got to understand is that the Arctic is one of the harshest testing environments for electronic equipment.' He tells me that some of the Survey's gear was tested in simulated Arctic environments at MIRA, the transport technology test facility. But it's not really until you get your kit out on the ice, putting it through its paces day in day out, packing it, unpacking it, throwing it over pressure ridges, that you get a feel for how much stress you're inflicting on it. Man-hauling even ruggedised kit to the North Pole is a destructive business.

Before discussing the kit, Hartley is keen to describe the effect the Arctic conditions has on humans. 'When you've immersed yourself into an environment that is, at times, colder than -40C for weeks, it has an effect on your psychology and your physical state. There's a lot of physiological pressure on you simply to survive, and the psychological pressure is enormous.' He stresses the importance of diet: 'If you don't throw enough fuel on the fire you get cold very quickly. And when you get cold quickly the first things to go are your fingers and toes. When that happens, you can't do your job properly.'

The reason why Hartley and his two fellow explorers - Ann Daniels and Charlie Paton put themselves through this on the Arctic ice, is to take measurements and transmit the data and associated imagery back to civilisation. This means that the survey carries with it a lot of electronic kit: from the sensors and instrumentation that collects the data to the specially adapted computers, modems and other telecoms gadgetry that transmit it. There are navigational devices, satellite phones and, of course, cameras.

Hartley has been on over 20 polar missions now and is regarded as one of the toughest, most experienced and unflappable of a new generation of explorers. He usually goes along as expedition photographer and filmmaker, and so he's used to relying on electronic equipment that works well in theory, but becomes temperamental when cold. In fact, on the 2009 Catlin Arctic Survey, a thermal trip switch in the power unit that refused to reset compromised the ice-penetrating radar - and so some of the key data sets. As Hartley says: 'Now that the post mortem on last year's expedition has been done, I can tell you that the radar was still working, but there was a problem with the batteries.'

The first problem affecting Hartley's equipment was simply that extreme cold affects the mechanical tolerances within the camera, making the lenses difficult to adjust. Don't even think about autofocus, he says, because that packed up ages ago. Focusing becomes a test of brute force where 'you hold the camera with one hand and yank the lens with the other'. Also the leaf shutters that slide over each other inside the lens to create the aperture become tight and jam. But this is just the mechanical side of things.

The arctic chill

The real problem is that at around -40C (or even a bit warmer than that) the electronics start to slow down, which creates shutter-lag. But that's only the start of it, because the LCD screens on the back of most cameras don't work below -25C - and even the so-called 'low temperature screens' shut down once you get below -35C. 'On one of my cameras,' says Hartley, 'the view finder is electronic, and so what you're looking at is the image on the chip, and they don't work in the cold either.'

In short, cameras don't like the Arctic chill, something that makes the life of a polar photographer a perpetual nightmare. But they don't respond at all well to humidity - either from your breath or from the continual boiling of water in the tent. The moisture gets inside the lens and forms ice crystals. Then it gets on the circuit boards, refreezes and can cause them to fail.

But the big deal is power. You have to warm batteries up to -10C 'otherwise they're very inefficient'. Hartley says that if you want to maintain battery life the trick is to keep them warm, which on an expedition like this is easier said than done. He explains that the best way to do this is to carry them as close to your body as possible.

Hartley's exploration suit has been adapted to include pockets for his batteries on both the front and the back of his legs, to be used depending on whether he's walking with or against the wind. Legs pump out lots of heat.

'The battery itself has to be kept in a plastic bag because along with the heat, I'm pumping out sweat, and when sweat gets on the battery contacts' well, they don't like that either.'

So it's a bit of an urban myth then that explorers sleep with their batteries in their armpits? 'I used to do that, because I used to think that batteries had to be kept warm all the time to preserve the power. But, in fact you can let a fully charged battery go as cold as you like. If you warm it up it will work.'

Battery power

He goes on to explain how in Antarctica research teams disconnect the batteries on their snowploughs and skidoos when they abandon them for the winter. Down south it can get as cold as -90C at Vostok, but when the batteries are reconnected at the start of the season six months later 'the engine will start first turn of the key'.

The 11.1V battery in Hartley's top-of-the-range Nikon D3X digital SLR will at room temperature (20C) produce 1,500 photographs. 'But at -40C I get 50 shots.' He admits this 'might be a bit conservative' but the fall-off in performance relative to decreasing temperature is colossal. It's also annoying for the photographer, who has no way of charging his batteries with solar panels in the Arctic.

Up north, at the start of an expedition there's only a couple of hours ambient light per day and no direct sunlight. When the Sun gets above the horizon and there's 24-hour daylight, there's too much fog to charge the batteries. He carried a total of 16 batteries to last 60 days, and with careful management and strategic periodic resupply he managed to bag 5,000 shots.

To transmit these images - along with audio blogs and video - back to expedition headquarters, two modified Iridium wireless-network modems were set up along with a flashcard reader and the expedition computer in a hermetically sealed box. On earlier expeditions, when Hartley sent pictures using standard equipment such as an a small personal digital assistant - a HP Ipaq - and one Iridium satellite telephone, it would take 45 minutes to send 200KB. 'With our set-up on the 2010 survey, I could send a highly-compressed JPEG at a transfer rate of 1MB per hour.'

The system was designed so that if the signal got lost the auto-redial and connect procedure allowed the transmission to pick up where it had left off, 'which saved a lot of time. I was successfully sending back 900KB files, which, when opened up and expanded properly, were getting on for 24MB - very tasty'.

When it comes to the expedition computer - designed to include a heater plate to keep its temperature at about -25C - the original plan was for it to be connected to the main battery for the duration of the survey. But in practice this caused problems, as it meant leaving the computer outside the tent at night. But Hartley made the improvised decision not to do this: first to conserve the battery, but more importantly there were issues with the connecting cable. 'Although it was a low temperature cable, it wasn't flexible enough when it was moving in the sledge, and so there was the risk of it simply snapping.'

Were there any nasty equipment failures? 'No, none at all.'

Hartley explains that this time everything had built-in power supply backups and that the computer had been designed specifically for one redundancy cable failure. There were two connectors on the computer and two on the battery. If one connecting device failed there was another way of connecting the computer to the battery. Likewise the 'Yeti box' - a modified beer cooler that was used to keep the water samples from freezing - had two heating elements in case one broke.

According to Hartley, the moral is this: if you want to conduct a scientific survey in the worst conditions the planet can throw at you, it all comes down to battery husbandry.

Hartley recalls how on the Catlin Arctic Survey 2009 for the first 10 days he was unable to take any photos. 'It was simply too cold. It felt like weeks.' Determined not to be in this position ever again, earlier this year he took with him the ultimate back up - a Leica MP. This is a purely mechanical rangefinder film camera that requires no power to operate it (although the onboard light meter requires power.) 'There are no batteries required to make the camera work,' says Hartley of his £3,000 piece of kit. 'If you want to be absolutely cold proof you need one of these. It was built in Germany and tested in a cold weather chamber before it came to me. But even then you've got to be careful because in these temperatures you can easily snap the film.'

To read about how the Catlin Arctic Survey was project managed by legendary explorer Pen Hadow turn to page 68