Littorio Class Battleship - Design - Armor

Armor

The ships' belt armor was designed to defeat 380 mm shells at ranges over 16,000 m (52,000 ft), and was inclined at 11 degrees. The belt was layered as follows: a 70 mm (2.8 in) hardened steel belt was used to de-cap armor-piercing projectiles. A 250 mm (9.8 in) wide gap separated the outer layer from the main belt armor, which was 280 mm (11 in) thick and was backed with 50 mm (2.0 in) of timber and 25 mm (0.98 in) skin plating. Another 140 mm (5.5 in) wide gap separated the main belt from a 36 mm (1.4 in) thick splinter screen. Another 25 mm thick screen was placed further inboard. The main section of the belt armor was closed on either end by 70 mm (2.8 in) thick transverse bulkheads. The bow was protected by a 60 mm (2.4 in) thick belt, while the stern was given 125 mm (4.9 in) of armor protection.

Horizontal protection over the magazine consisted of a 162 mm (6.4 in) thick armored deck. Over the machinery spaces, the deck was reduced in thickness to 110 mm (4.3 in), and on the outboard portions of the ships, the deck was reduced further to 90 mm (3.5 in). The aft steering rooms and auxiliary machinery spaces were protected by a 105 mm (4.1 in) thick deck. The main conning tower was protected by 50–130 mm thick side armor.

Above the deck, the main battery barbettes that housed the turret assemblies for the 381 mm guns were protected with 350 mm (14 in) thick armor, while below deck the thickness was reduced to 280 mm. The faces of the main battery turrets were 350 mm thick, with 200 mm (7.9 in) thick sides and roofs. The secondary gun turrets were housed in barbettes 150 mm (5.9 in) thick above deck and 100 mm (3.9 in) thick below deck. The turret faces were 350 mm thick, with 75 to 130 mm (3.0 to 5.1 in) thick sides and 150 mm thick roofs. Below the third deck, neither the primary nor secondary barbettes were protected by armor. The anti-aircraft guns were protected with gun shields ranging in thickness from 12 mm (0.47 in) to 40 mm (1.6 in).