Preserving more than 100 years of floating history in Stockholm
Oct 5, 2026
In Stockholm harbor, next to the Vasa Museum, lies another important piece of Swedish history: The icebreaker Sankt Erik.
Built in 1914 at Finnboda shipyard in Stockholm, Sankt Erik was Sweden's first seagoing and only surviving icebreaker. For more than six decades, she helped keep vital sea routes open during harsh winters, ensuring that goods, mail, and passengers could reach Stockholm and other parts of Sweden when ice blocked the waterways.
The vessel played an important role in Sweden's economic and industrial development at a time when Stockholm was rapidly expanding. By keeping shipping routes open year-round, Sankt Erik helped maintain trade and communication with both the Swedish archipelago and the European continent.
Today, the historic vessel serves as a museum ship at the Maritime Museum's pier on Djurgården, where around 70,000 visitors come each year to experience Sweden's maritime heritage firsthand.
Preserving a museum ship of this size is no easy task, especially when it remains exposed to the elements year-round. Unlike museum objects kept in climate-controlled buildings, Sankt Erik sits in the water every day, constantly affected by changing temperatures and humidity levels.
"Humidity is a major challenge here because this is a ship that remains in the water year-round," says Ola Dahlqvist, Technical Manager for the museum ships. "Moisture comes from both above and below, so if we switch off the dehumidification, problems develop very quickly."
For the museum team, controlling humidity is not simply about maintenance. It is about protecting an irreplaceable part of Sweden's cultural heritage.
"When humidity is not controlled, we see rust, condensation, and mold appear very quickly," says Benjamin Hedlund, Senior Exhibition Technician, Historical Vessels Unit at Swedish National Maritime, Transport and Military Museums. "The problem is that many of the ship's components are original. Once they are damaged, they can be very difficult, and sometimes impossible, to replace."
Today, three Munters dehumidifiers protect the vessel's main machinery spaces. Installed in 2014, and fully commissioned in 2015, the units have operated almost continuously ever since. According to Dahlqvist, they are now approaching 100,000 operating hours.
"We have very good experience of their performance," he says. "Once a year, Munters service technicians come onboard to perform capacity checks and inspect the system. It works very well."
Before the dehumidification system was installed, moisture was a constant problem. Condensation formed on the inside of the hull, water collected in machinery spaces, and rust developed on metal surfaces. Mold growth appeared on wooden interiors, creating both preservation and maintenance challenges.
"The environment onboard was not good before we installed the dehumidifiers," Dahlqvist recalls.
Today, the difference is visible throughout the vessel. Metal surfaces remain clean and protected, original interiors stay dry, and visitors can experience the ship much as it appeared during her years in service.
For the team responsible for her preservation, the goal is simply to ensure future generations can continue to walk her decks, explore her machinery spaces, and experience an authentic piece of Swedish industrial history.
"As long as we keep the sea out, the rain out, and maintain the climate onboard, there is really no limit to how long the ship can survive," says Dahlqvist. "If we take care of her, she can remain here for generations to come."
