Application Technology

Expanite AS – the Danish pioneer of surface hardening of stainless steel and titanium – states that its ExpaniteHard-Ti solution has enabled the development of an autonomous underwater winch for the Alfred Wegener Institute.

The special winch is a key component and will help provide continuous physical and biogeochemical data from the surface of the Arctic Ocean in the Fram Strait area. The winch will hover at a depth of about 150m on a long, anchored rope that rises vertically in the water. From this position, once a day, a measuring unit with different sensors will rise to the water surface. The sensors will measure the water temperature, salt, oxygen, and carbon dioxide content, as well as the chlorophyll fluorescence in the different water layers, during the test run through the water column.

Accompanied by the designer of the underwater winch, Dipl Ing Normen Lochthofen, and the anchoring specialist of the deep sea group, Dr Eduard Bauerfeind, test runs took place at the Sven Lovén Centre for Marine Infrastructure in Tjärnö, Sweden, because only there, less than 15 minutes by boat from the research station, the water depth is up to 200m and deep enough for testing.

“The solution from Expanite® is an essential part of our special winch,” explains Lochthofen. “With the ExpaniteHard-Ti surface hardening, the stressed titanium components will withstand significant wear and thus prevent long-term use of the winch system. In addition to the increased surface hardening of up to 1,000 HV, the corrosion resistance of the material is improved at the same time, and use in seawater is made possible.”

In the late summer of 2019, the five week expedition took place in the Fram Strait between Spitsbergen and Greenland. “We launched two winch systems that will collect data over the next two years. Not an everyday project,” said Norms Lochthofen.