Open doors left behind by men abandoning ship allowed flooding to spread through an already damaged hull. Shell damage had opened the ship, and torpedo hits added to the flooding. Protecting the upper command positions against close-range sixteen-inch salvos would have required substantial armour. That protection would also have added weight high in the ship.
Notable Point · 4:16:13-4:16:44
Flooding and upper command protection during Bismarck's final action
Open internal doors worsened flooding, while armour sufficient to resist Rodney's heavy shells would have imposed a large weight penalty high in the ship.