Flakfortet

Flakfortet

Flakfortet island
Flakfortet
Geography
Coordinates	55°42′11″N 12°43′55″E / 55.703°N 12.732°E / 55.703; 12.732Coordinates: 55°42′11″N 12°43′55″E / 55.703°N 12.732°E / 55.703; 12.732
Area	0.3 km2 (0.12 sq mi)
Highest elevation	23 m (75 ft)
Administration
Denmark
Demographics
Population	None permanent

Flakfortet, meaning sand-shoal fortress, is a sea fort located on the artificially built island of Saltholmrev, in the Øresund between Copenhagen and Saltholm. The island and fort are simply known as Flakfortet; the name of the island; Saltholmrev, meaning the reef near Saltholm, is seldom used.

Flakfortet was the last of three artificial islands that the Danes created to defend the entrance to Copenhagen's harbor. (The other two are Trekroner Fort (the oldest) and Middelgrundsfortet.) Flakfortet's guns covered the Hollænderdybet channel between Middelgrundsfortet and Saltholm, and the Flinterenden channel between Sweden and Saltholm. Eventually Flakfortet became more of a site for anti-aircraft weapons than for coastal artillery. Its military functions ended in 1968.

Flakfortet is currently used for recreational purposes such as concerts, and the site has a restaurant and yacht moorings. During the summer, a ferry company, Spar Shipping, has five scheduled trips per day to the island, with the trip from Nyhavn taking about 40 minutes each way. There is an overnight hostel on the island too.

The fort was built in the years 1910–1914 as part of Copenhagen's sea-fortifications. The island is 23 meters high and covers 32,000 m2. Construction of the artificial island required the use of caissons of reinforced concrete, possibly the first use of such structures. The caissons were first cast at Lynetten quai on Refshale Island, though the last was cast at Flakfortet itself.

The fortifications extended over two floors and included a barracks that once housed the garrison of 550 men. Initially, the fort's armament consisted of four 29cm M1910 howitzers, six 21cm M1913 guns, and four 75mm quick-firing guns. Later, it received two 47mm ballonkanoner (anti-balloon guns), another 75mm, and 8mm machine guns. It also received one 90cm and four 150mm searchlights.