Date: 2024-08-16 Page is: DBtxt003.php txt00017999
Military
US Navy
How did the US Navy's Iowa-class battleships from World War 2 carry nine cannons that were each larger than the 8 cannons on a Bismarck-class battleship even though the Iowa was only a slightly larger ship?
Peter Burgess
Updated Dec 12 · Upvoted by Anthony Spellman, Masters Geospatial Information Science & Military History and Wars , National Geospatial-Intelligen… and Luke Kaul, Nuclear Electronics Technician 3rd Class at United States Navy (2018-present) Because Iowa was a newer, much more advanced and better design.
Bismark had to use 2-gun turrets, because germany did not have technology to load the guns if they are packed tightly in a turret. They could put 3 280mm guns to a turret but the guns in those turrets were positioned quite sparsely and the turrets were very wide, and 280 guns were much lighter and smaller than 380mm guns which Bismarck used. Having 3 turrets instead of 4 turrets saved a lot of weight for Iowa, also especially on the armour belt which did not have to be so long.
Here is an image of the turret of Scharnhorst or Gneisenau. See how much there is empty space between the guns
Here is a picture of the turret of Iowa-class battleship. There is much less empty space between the guns.
Bismarck had separate guns for the secondary battery and heavy AA guns. Iowa used same 5″ guns for both purposes. saving the weight of the secondary battery.
Bismarck secondary battery of 150mm guns shown here, 105mm anti-aircraft guns shown between and behind them.
Iowas 5″ dual-purpose turrets shown here:
Bismarck tried to have armour on everywhere. There was lots places with medium-thick armour. Iowa had “all or nothing” armour scheme meaning that the armour was practically always either very thick, or pratically non-existing; All the critical places of the ship had very heavy armour, but non-critical parts either no armour or very light armor. The huge amount of medium-thickness armour all around the ship made Bismarck much heavier, without increasing the survivability against heavy shells. Because of these three things, they could afford to have much more powerful engines and more powerful main guns in Iowa, while weighing only slightly more.