How were tanks originally classified?

As Landships. Armies had never utilized hatches, turrets, or internal cannons; consequently, armies had to turn to the Navy for technology. The first cannons (guns) installed in tanks were Naval guns. The nomenclature for tanks were adapted from Naval terms: hatches, turrets, sponson boxes, back decks, bow machine guns, and the hull, etc. The first tanks were designed by Naval architects.