 By mid-1869, the ironclads that the navy had begun to acquire under Jachmann's direction had started to enter service, permitting the formation of an ironclad squadron.At the start of the Franco-Prussian War in July 1870, Jachmann left Berlin to take command of the ironclad squadron based in Wilhelmshaven.At the time, Jachmann had under his control the ironclads , , , and .