Pinnau was a 1,198 GRT cargo ship that was built in 1922 by Nobiskrug Werft GmbH, Rendsburg, Germany for German owners. She was seized by the Allies in May 1945, passed to the Ministry of War Transport (MoWT) and was renamed Empire Constructor. In 1947, she was sold into merchant service and renamed Estkon. She served until 1959 when she was scrapped.