In the Battle of Denmark Strait, was hit repeatedly by 15 in (38 cm) AP shells, causing damage without seriously endangering the ship, however one 15" shell about a foot above the starboard bilge keel did not explode. A 8" shell from Prinz Eugen cruiser penetrated on the starboard side of the stern below the waterline. Splinter damage from this hit caused some flooding in the interior. Another 8" shell eventually penetrated 5.25" gun P3's casemate but did not detonate. The fact a cruiser shell could make their way in to those places shows the weakness of "all or nothing" armor scheme. , built using the earlier concept of banded armor, was most likely lost when an AP shell from "Bismarck" passed through a thinner upper belt or a thinly armored deck into a magazine, Though also built using the older banded armor design, vessels of the Kriegsmarine's proved difficult to sink, largely because they were well-built and highly compartmentalized. "Bismarck" withstood tremendous punishment during her last battle. Though an expedition verified that few if any British heavy shells penetrated the "Bismarck's" citadel, some main-turret barbettes were penetrated, and the ship was virtually destroyed above the armored deck by AP shells detonated by a medium thickness upper belt that did not prevent them from penetrating. "Bismarck's" sister ship "Tirpitz" suffered extensive topside damage from Royal Navy aerial strikes during Operation Tungsten but her vitals were relatively unharmed. "Tirpitz" was ultimately sunk by a high-altitude bombing attack involving massive Tallboy bombs that no practical amount of armor could have ameliorated; in particular, the Tallboy hit amidships between the aircraft catapult and the funnel blew a very large hole into the ship's side and bottom while completely destroying the entire section of belt armor abreast of the bomb impact, which contributed to the battleship's rapid capsizing.