File:GeschützDora2.jpg - Wikimedia Commons

Krupp 80 cm Kanone Schwerer Gustav (Dora) Railway Gun

Trivia: Gustav Max was based on Schwerer Gustav, the rail cannon made and used by the nazi germany, also considered the largest gun ever used in a war. : r/DuelLinks

File:DoraSchwererGustav.jpg - Wikimedia Commons

Solved 2. (5 points) According to Wikipedia, Schwerer

Artillery wagon - Factorio Wiki

Schwerer Mörserpanzer, The Wolfenstein Fanon Wiki

Karl-Gerät 040, Girls und Panzer Wiki

Krupp K5 - Wikipedia

Schwerer Gustav

HOI4 Dev Diary - Railway guns never tire, Page 10