He was Married and He was father of 6 Kids and lived With his Family in Duisburg(Germany).
U-111 was sunk on 4 October 1941 by HMS Lady Shirley, a Royal Navy anti-submarine trawler.
In 1937 he was promoted to Oberleutnant zur See (Lieutenant) and he then commanded a boat of the 1st MTB Flotilla.
Kleinschmidt is said to have been promoted to Kapitänleutnant (Lieutenant-Commander) at the outbreak of war.
He is described as having been a cautious U-boat captain who had never before attacked so small a ship as the Lady Shirley.