Zeppelins

It is late afternoon in the Kalahari Desert. In the distance, silhouetted against a National Geographic sunset is an airship. It is the length of a football field and it is cruising a few hundred feet above the parched soil. Below: giraffe and antelope scatter. But this is not a scene from an Indiana Jones movie. De Beers, the diamond company, is using a new generation of Zeppelins right now to prospect for diamonds in southern Africa.

The latest Zeppelin NT airship made its maiden flight in 1997. (Don’t say blimp – airships have a skeleton under their skin.) Since then Zeppelin have built two more in Friedrichshafen in south Germany, where the first ever Zeppelin took flight in 1900. One is being used by De Beers, another is in Japan, and the third is used for sight-seeing flights around Lake Constance near the factory, and was recently employed by the German authorities to police the soccer World Cup. A fourth airship is currently under construction.

It is possible to buy your own Zeppelin. The list price is €8.5 million, plus the cost of ground equipment such as mast trucks. “It’s like operating any aircraft,” says Thomas Brandt, the manufacturer’s CEO, “you need maintenance, certification, pilots but it is normal aerospace business.” Once ordered, a new airship takes about 18 months to build – plenty of time to get the pilots trained up.

This isn’t your grandparent’s airship. The Zeppelin uses three engines to reach a maximum speed of 125km/h. It can hover like a helicopter and dock and undock under its own power – no need for dozens of men with ropes anymore. The company has also dispensed with explosive hydrogen as a lifting gas in favor of inert helium. No more Hindenburgs.

The airship’s gondola can carry 12 people plus two pilots. BMW hired one to tour ten German towns. The aircraft carried the carmaker’s logo across Germany and it took nearly 2,000 VIP passengers for short flights. This is an eye-catching form of publicity.

Life for most of Zeppelin’s aircraft is a mix of pleasure flights, airborne surveillance and BMW-like charters. Brandt reckons it is possible for a well-managed Zeppelin to pay its way like this. De Beers, however, shipped one to Africa and use it for something altogether more serious: hunting diamonds. They removed all the club class seats and replaced them with sensors and instrumentation.

It is an ideal survey platform because it has less vibration than a light aircraft and can stay aloft for up to 24 hours. Advanced instruments, including one originally developed for the US Navy to hunt Russian submarines, scan the geology beneath the Earth’s surface for Kimberlite. These buried volcanic pipes hint at the presence of diamonds.

The De Beers Zeppelin is based in Botswana at the Jwaneng diamond mine because the best place to look for new diamonds is near an existing field and the gravimetric sensors are particularly effective in areas that are known to be promising.

It operates a few hundred feet above the ground flying up and down track lines like a grounds keeper mowing a football field. The slow speed and low vibration generate high quality data. David Hatch, a De Beers geophysicist, says: “As well as being fun – you get to fly around in an airship – it’s also been a huge technical success.”