The history behind the installations on Hemsön

From the late 19th century, there were thoughts about the need for a fortress at the deep estuary of the Ångerman River to support the movements of the navy in these waters. The 1914 defense decision meant the establishment of Hemsön Fortress and the establishment of Hemsön Coastal Artillery Corps. This was done with the aim of protecting the economically and militarily important inlet to the Ångerman River. A naval depot was to be located in Ådalen, and a dock was built in Gustafsvik. It was not until the 1920s that plans began to be realized.

In 1916, construction work began on Hemsön. Work on Battery Dalom on the northern part of Hemsön continued, and the battery was completed in 1922. The battery, which was blasted into the mountain, consisted of two 15 cm cannons and two searchlights. The decommissioning of this battery began when the battery at Storråberget was built.

The 1925 defense decision meant that Hemsö Fortress was placed in the reserve, as was the naval depot.

At the outbreak of World War II in 1939, rearmament began, and the 1942 defense decision meant significant reinforcements to the coastal defense. In 1939, Hemsö Fortress was manned again, mainly from Vaxholm. According to the 1942 defense decision, Hemsö Fortress was to be developed into Sweden’s largest fortress ever. The decision also meant reinforcement of the coastal artillery at the northern Swedish ports, and several mine lines were added in the waters at the mouth of the Ångerman River.

The threat during the Cold War also led to a significant expansion of defense along the Norrland coast with modern facilities in the mountains, which began in the early 1950s. Between 1953 and 1957, the battery at Storråberget was built, and between 1961 and 1963, the light battery at Havstoudd was built. Between 1967 and 1968, the measurement station on Kläffsön was built.

Gustavsviks Naval Depot, now called Gustavsviks Shipyard, was established between 1916 and 1922 under the auspices of the navy. The location was chosen for its geographical conditions, including several outlets to open water, hilly terrain, deep water levels, and favorable ice conditions. The depot was also well protected by Hemsön Fortress.

The dry dock is still in use today.