Heusner was born in Perl (today in the German state of Saarland). He entered the Prussian Navy in 1857, and in 1859–1862 he took part in on an expedition to the Far East on the frigate Thetis. In 1864 during the Second Schleswig War he commanded the Prussian gunboat the Wespe, and then was in the following years stationed in the Mediterranean and the West Indies. In 1872 he did survey work in the Baltic Sea and in 1873 and was chairman of the Torpedo Examination Board or Torpedo Depot at Kiel-Friedrichsort where he and Otto von Diederichs worked on the Whitehead torpedo.By order of the Kaiser, p. 48
