When JC was talking of the Tirpitz and comparing shell weights he also mentioned the thickness of her armour. I think he made a slip in units when talking on the thickness of her armour.
Her main belt protecting the machinery spaces etc was 13 inches and that on the main turrets was 14 inches. Her weakest spot was her main deck between 3.9 and 4.7 inches.
Now it was a truism at the time that you needed an armour piercing shell of greater diameter than the thickness of the armour. It follows that only plunging shot from the 6 inch gunned cruisers would have been effective against the main deck.
Last edited by Pontius Navigator; 4th Jan 2014 at 13:08.