Naval power.

Evocative of eighteenth-century naval warehouses and ropewalks, this maritime museum in Karlskrona forms a dignified addition to a historically resonant setting.

For 400 years, Karlskrona has been the main base of the Swedish navy. A fortified port on the south-east coast of the country, it commands the southern Baltic from a series of interlocked islands and basins blasted out of the granite. The naval museum originated in the model collection established by the master shipwright Fredric Henric af Chapman in the middle of the eighteenth century, and even though part of his collection was moved to Stockholm in 1907, enough remains to merit a special exhibition building, particularly now that the models are supplemented by a collection of figureheads and by some real vessels including a minesweeper and a torpedo boat.

A competition was held when the local authority took over Stumholm (one of the islands of the group) and the winning scheme by Hederus Malmstrom took its tone from the austere eighteenth-century military warehouses and ropewalks of C. A. Ehrensvard. The island is dominated by the 1787 Sloop and Launch Shed which is still in use as a workshop for the creation of replica historical ships which are tested in the Baltic. The new building is on a 145m pier which juts out north-east into the sea towards the central island of Trosso next to the dock of the Sloop and Launch Shed. By using the pier, the small island could be preserved more or less intact, and the new museum could be brought into more intimate contact with the harbour and the whole naval complex. To the west, the long building is hard up against the sea, with a wooden quay separating it from the boats moored alongside. Here the long white rendered elevation is pierced only by small square windows, except at the ends where the concrete structure is exposed as an abstracted order round the two double-height glass volumes of the entrance hall (to the south) and the figurehead exhibition hall at the end of the pier. To the east, the building presents a very different appearance, breaking down into a series of irregular volumes clad in wood painted in tar and traditional Falu-red (the rich, red of Swedish country buildings made from by-products of the copper industry). In the east side's higgledy-piggledy picturesqueness the architects intended to evoke 'something Swedish and friendly, like an old wooden boatyard or a backyard workshop in a small town'.

Internally, the two storeys are formed into a series of exhibition galleries arranged in enfilade. The upper ones are largely top-lit while those on the lower floor have much more restricted daylight to preserve delicate objects. The sequence culminates in the extraordinary Baroque figureheads by the sculptor Johan Tornstrom which writhe toward the light and the heart of the military complex (at night their glass box becomes a beacon for the whole harbour). One extraordinary feature of the building (illustrated in the sections on p50 and p52) is the underwater gallery. In the course of building the new museum, the wreck of the early eighteenth-century battleship Gota Leijon (Gothic Lion) was discovered on the sea bed and, being a national treasure, it was not allowed to be disturbed. The architects devised a transparent waterproof tube which is suspended above the mud from the new structure. Reached by lifts and stairs, the gallery of glass reinforced plastic (made in the same yard as the Gota Leijon) allows visitors to see the old ship as it has lain for centuries. The super aquatic galleries are very simple and workmanlike, with white walls and plank floors like a ropewalk. They are appropriate spaces in which to exhibit the naval artefacts, and though one may have a few reservations about the abstracted Doricism of the ends (and occasionally rather basic detailing like the balustrades), the whole building is an excellent addition to its historically resonant setting.

Architect Hederus Malmstrom arkitekter, Stockholm

Project team Per Hederus, Bjorn Malmstrom, Asa Conradsson, Peter Grodinger, Palle Widegren, Sanna Hederus, Ebba Hogstrom, Andreas Jonasson, Olle Jureen, Ake Axelsson

Landscape Landskapslaget AB: Tomas Saxgard

Structural engineer J & W; Tyrens

Services Scandiaconsult

Lighting Per Sundstedt

Acoustics Tunemalm Akustik

Photographs Jens Lindhe