In 1877 he left the Torpedo Depot and was sent with Tirpitz to the Whitehead Torpedo works (Torpedo-Fabrik von Robert Whitehead) at Fiume to further study the torpedo.[2]
In 1878 to 1880 he was posted to South America to protect the interests of Germany during the War of the Pacific. Here he also supervised the observance of the neutrality laws. In 1882 Heusner was Chief (Dezernent) of Section A1 (Military Utilization of Ships/Militärische Verwendung der Schiffe) of the Admiralty's Military Department (Militärische Abteilung), which was headed by Eduard von Knorr. In March, von Knorr put him to develop 'Plan-O' for naval operations against Russia in case of war. His plan called for an attempt at a quick and decisive battle to cripple the Russian fleet, followed by the mining of ports and blockade by a screen of light warships.[3] In 1883-87 he commanded the armored ships (Panzerschiffen) SMS Deutschland and SMS Oldenburg and then the squadrons off Australia and East Africa.
By order of the Kaiser: Otto von Diederichs and the rise of the Imperial German Navy, 1865-1902 by Terrell D. Gottschall; Institute Press, 2003, 337 pages.
Hans H. Hildebrand; Ernest Harriot, eds. (1989). H-O. Vol. II. pp. 87–88. {{cite book}}: |work= ignored (help)