POLARSTERN – A ship unlike any other
The German research vessel POLARSTERN has been sailing through the polar regions of our planet in the service of science for nearly 30 years. Many a conventional vessel would already have gone to the ship’s graveyard by this time. The POLARSTERN, however, defies age thanks to good care and keeps pace with the times as far as technology is concerned. In an interview Captain Uwe Pahl and Engineer Ralf Krocker talk about the capabilities of the ship and what innovations can be found on board.
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.
Up to what ice thickness can POLARSTERN make its way through sea ice?
Captain Pahl: It’s difficult to set a limit because sea ice is always different. Winds, surface currents, tidal movements and snow cover change it constantly. As an illustrative reference figure, POLARSTERN can move through homogeneous, smooth ice having a thickness of 1.2 metres at a speed of around 4 knots (nautical miles per hour). If the ice cover is thicker or the ice floes pile up to form ice ridges that are metres thick, careful tactical navigation is the only thing that helps. Then we utilise cracks and other weak points in the ice to make our way through. If that’s not possible, the last recourse is so-called ice ramming. This means repeatedly running into the ice at full speed and with frequent run-up.
Ralf Krocker: Such a ramming operation is extremely strenuous. I’ve experienced it personally before. On that occasion we wanted to get to Neumayer Station in Antarctica. Due to the wind, however, a lot of pack ice had been pushed into Atka Bay so we had to ram. That cost us a whole week and plenty of fuel. In such situations the ship runs on all four engines, which is normally avoided as far as possible for cost reasons. The expenses for fuel now account for more than 50 percent of the operating costs.
POLARSTERN celebrates the 30th anniversary of its launch this year. Is the ship an old steamer?
Ralf Krocker: Theoretically yes. However, scientific vessels are always well maintained. POLARSTERN, for instance, was completely overhauled for the first time after 15 years. Now, after 30 years, it is time for the next overhaul. You see that age-related damage is gradually appearing everywhere.
Kapitän Pahl: Mariners tend to endearingly personify their ship and thus one could say in this context that a person can remain enormously productive even at an advanced age through activity and a healthy lifestyle. In the figurative sense this means for our ship that continuous maintenance and modernisation of POLARSTERN have contributed to enabling it to perform its operational tasks without restriction and without any reduction in performance.
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.
What innovations are there on board the POLARSTERN in terms of research technology?
CaptainPahl: Currently the multibeam echo sounders of the ship are going through extensive maintenance and calibration tests. Extensive sections of the Arctic and Antarctic have not been surveyed at all yet or only to an inadequate degree. Deployment of our equipment can make a major contribution to precise coverage of the still unknown marine areas in this context. In addition, the international community is currently drawing up shipping regulations for Arctic and Antarctic marine areas that will lead to a Polar Code in the near future. The consultations will also involve a description of the specific risks for shipping in these regions that primarily include inadequate surveying. Deployment of the POLARSTERN with its modern surveying capabilities is certainly regarded as a key contribution in this connection.
Ralf Krocker: Another new development is WAMOS – a radar system that measures wave height and direction. The procedure up to now has been that an experienced meteorologist looks at the sea every three hours and records both wave characteristics. WAMOS is designed to support these observations and perhaps even replace them in the long run. This system is still in the test phase, however.
Thank you very much for this interview.