Captain Pahl, Mr. Krocker: The research vessel POLARSTERN is regarded as the flagship of the German research fleet. What distinguishes this ship from the other research vessels?

Captain Pahl: POLARSTERN’s special features are already expressed in its operational designation, i.e. Germany polar research and supply vessel. With a length of 118 metres POLARSTERN is not only the largest Germany research ship. It can also load considerable volumes of cargo for supply tasks in comparison to the other vessels. We not only use POLARSTERN to supply the Antarctic research station Neumayer Station III, but also stations of partner nations, such as the British Rothera station. The loaded supply goods may be general cargo lots, 20-foot containers, refrigerated lots or liquid cargo like aircraft fuel or Arctic diesel.

Ralf Krocker: POLARSTERN is additionally Germany’s only icegoing research vessel without any restrictions. It was built for the high ice class ARC 3 and its hull is reinforced with steel plates, its front section even has a double hull construction. The weight of this ice protection is the reason why POLARSTERN has an enormous draught of 11.20 metres.

Captain Pahl: Then there is also the relatively large transport capacity. The ship can hold a total of 124 persons, of whom a maximum of 44 persons are crew members. Scientists who undertake expeditions with POLARSTERN experience the ship as a universal research platform. There are, for example, laboratories, 16 winches, four cranes, shipboard-based helicopters for scientific and logistics missions, complete fishery gear for bottom trawl and pelagic fishing as well as instruments for seismic research. In addition, a high-pressure compressor for 200 bar air pressure and multibeam systems are available. The latter are used to survey the deep sea and investigate the sediment layers of the seafloor. This list is by no means exhaustive, however.

In 30 years technology in particular has made enormous advances. What innovations have taken place on board during this time?

Ralf Krocker: Particularly noteworthy in this connection are our further improvements in the IT sector. A computer room with computers, printers and plotters has been set up. In 2008 we installed a dedicated Internet line. Until that time the crew and scientists were only able to send their measurement data and e-mails three times a day via satellite connection. That means the e-mails were sent en bloc in the morning, at midday and in the evening. Now this can be done at any time.

POLARSTERN just returned from a long voyage in Antarctica. What parts of the ship have suffered from the extreme environmental conditions the most?

Captain Pahl: Sailing through ice places stress on the hull in particular. Because of the vessel’s solid design, however, no major damage has occurred thus far. The ship’s propellers are subjected to stress due to ice contact, this also applies to the helm. In the sections above water level extreme minus temperatures influence the operation of all winches and cranes. We always clear snow and any ice that forms very quickly for safety reasons – especially to ensure that we can walk on the decks without risk.

Ralf Krocker: If the ship goes into dry dock after such a long voyage, a dock inspection takes place. This means all responsible experts walk around the vessel once to see whether there are any dents in the hull – which, as a matter of fact, is always the case. The last time we discovered small holes. They never went completely through the steel plates, but were big enough in diameter that you could stick a pen through them. The rest consists of general signs of wear, such as rust, which for the most part is only superficial, however. In such cases it is sufficient to grind and repaint these areas once. Otherwise POLARSTERN is operated very sensibly. The nautical officers and captains deserve great praise. They guide the ship very smoothly through the ice.