In 1756, the Swedish Archipelago Fleet was created alongside the regular navy and placed under the command of the army. One of its two squadrons was stationed in Stockholm and the other in Viapor. Augustin Ehrensvärd was appointed commander of the island fleet and, at his suggestion, it was officially named the Army Fleet.

during the war, Augustin Ehrensvärd met Fredrik Henrik af Chapman, a master shipbuilder in Pomerania, who was commissioned to design and build a new type of ship for the difficult waters of the Baltic Sea. The ships were named after the Finnish provinces. The Viapor shipyard was completed in 1764 and under af Chapman's direction some of the ships of the Viapor escadrille and a number of other vessels were built there.

the scale models of the ship types designed by F. H. af Chapman were made by Frans Rosell in the 1930s.