From 1920s to 1950s
In 1922, after World War I, the Finnish State took over control of Harakka in accordance with the Dorpat Peace Treaty. The imposing main building on the island, the Finnish Defence Forces’ chemical test facility, seems to have taken over from the rapidly fading traces of the nineteenth century. The building, designed by the architect Oiva Kallio, was completed in 1929 and is a well-preserved specimen of the 1920s classical style.
The construction and operations of the chemical test facility is described by Erkki Päiväläinen in his book Kemian Vuodet Harakassa, published in 1988. In 1927, an open architectural competition was launched for the chemical facility. Later that year, Hilding Ekelund and H. Holmberg, as well as Oiva Kallio, were invited to submit plans. Oiva Kallio’s proposal won the competition and, based on his submission, architectural plans for the facility were drawn up in 1928. The military look of the project is likely to have pleased the judges but in the final version of the plan Kallio rejected the empire style, although in most respects he retained the original profile of the façade. In the 1929 building plan, the arched portals are retained, although due to shortage of funds this feature was dropped from the plan for the wings. When the building was finally erected, the portals had been omitted.
In World War II, year 1944, during the bombardment of Helsinki in World War II, Harakka was hit by 13 bombs, which damaged the Nikolai batteries and the building’s main façade facing the sea. The latest building work at Harakka, undertaken in the 1950s, included a concrete bunker, which was used mainly to decommission military equipment.