South American Treaty Fast Battleships Armour Scheme (In Quick Detail)

## Introduction

South American Treaty Fast Battleships "Chaco Austral, Diamantina, Mesopotamia and Costa Rica Classes" follows an all or nothing armour scheme with 54% of the ship's length being relatively unarmoured while the 46% being armoured. The South American Fast Battleships have 3 sections of importance of value in South American Navy Designs which are.

## **Armour Scheme**

1.1: The Citadel of a South American Treaty Fast Battleships follows a armoured box deep in the ship which only protects the machinery and magazines with a exterior belt with decks above the armoured box only having splinter protection. "The armoured box thickness depends on which class it is with the Chaco Austral Class being only 6 inches while it's 9.4 Inches maximum on the Costa Rica Class while Diamantina's and Mesopotamia's are somewhere in middle with Diamantina's being 7.1 while  Mesopotamia's being 8 inches respectfully. While the splinter protection above is around 1.25 inches." Unique thing about armoured box on South American Fast Battleships they are only accessible from the top from second deck this was done intentionally to prevent flooding from accessing the machinery and magazine spaces from being flooded from a nearby compartments. "The Armoured Box itself only has two access points which are stairs on both edges of the Armoured box on the portside and starboard major disadvantage is the damage control effectiveness goes down drastically due to complexity of the access and also problemed by the extreme subdivide nature of the armoured box." The Armour Belts on Treaty South American Battleships varied on classes with Chaco Austral having lowest being 13.5 Inches while Mesopotamia's being second highest at 15.1 Inches while Diamantina's are 14.8 Inches the highest is the Costa Rica Class with 16.8 Inches"

1.2: Torpedo defence On South American Treaty Fast Battleships depends on which class the Diamantina, Mesopotamia and Costa Rica Classes have torpedo defence which consist seven layers of depth with total depth around 6 meters. While Chaco Austral Class is around 5.5 Meters Deep which consist six layers of depth with total depth. The main belt dose extends down to waterline but it's last layer of the torpedo defence but the Armoured Box is last line if a torpedo managed to defeat the seven layers around the magazines and Machinery spaces but it's six layers not around those spaces. South American Torpedo Defence is made of series of liquid and non liquid filled void spaces. "South American Torpedo Defence dose not extend past turret 1 or 3 which turret 1 is A while 3 is X. The bulkhead thickness on all South American Treaty Battleships is 13.8 Inches."

1.3 Superstructure: The superstructure on all Treaty Battleships that South American Navy built is lightly built with only 1.25 Inches at best with the conning tower only having 3 inch face while back of the Conning tower is 1.5 inches. "The Conning tower protection is only there stop destroyer calibre shells and not designed to stop anything larger."

## South American Armour Plate

### **Class SA/R**

#### **History**

Class SA/R Armour is South American Navy classification of Rolled Homogenous Armour that is greater than 3 inches in thickness. It's Generally used in ship construction of Bulkheads, Barbettes, Turret Face Plate, Heavy Deck Armour as Turret Roof. South American Navy's Class SA/R Armor still manufactured by the same single steel maker (Gerdau.), but now all armor of a given type was made by the same manufacturer on a given single, with no more mix-and-match. Significantly improved steel, but only a slight improvement in ballistic protection, since this form of armor had always had plenty of toughness and very little yield strength. The main advantage of this new armor was its ability to absorb shock loads without cracking or breaking apart. This was accomplished through the use of two layers of metal instead of one, which were then riveted together at right angles. This was called "Double Thick" armour because it consisted of two layers of metal, each layer being 1 inch thick. The first layer was 2 inches thick, while the second layer was 1 inch thick. Thus the 3 inch which often limited Class SA-2 Steel which is high-tensile steel. But Class SA/R is required to make the 13.8 Inch Bulkheads commonly as well the armoured decks greater than 3 inches thick. As well expected to absorb a torpedo warhead detonation without failing or glancing hit from a naval shell. "As well the Armoured Boxes" The primary disadvantage of double-thick armour was its weight, which increased the total mass of the ship. This meant less speed for the same power output, and thus a slower acceleration and deceleration rate. The problem was solved by using lighter materials for the outer hull, such as using 1.25 Inches of SA-1 or SA-2 Class of armour plate at 1.25 Inches in areas that not vital for the ships survival.

#### Table

* TENSILE: 92-118
* YIELD: 68-96
* Y/T: .74-.83
* % EL: 23
* % RA: 62
* BRINELL: 200-240

#### Parts made from SA/R Class Armour

* - Armoured Box around the machinery and magazines
* - Lower Section of the Main Belt
* - Face Turret of Primary Gun Turrets
* - Torpedo and Normal Bulkheads
* - Armoured Decks

### **Class SA/H**

#### **History**

SA/H Armour is South American Navy classification of Krupp Cemented Armour of Cruiser and Battleship Grade Armour Plate. SA/H Armour has 35% Harden Face while 65% softer back face. It was developed by the South America Navy in the early 1927 for use on their Battleships and Cruisers. The first ship to be protected with SA/H armour was the South American Navy Heavy Cruiser El Alto HC-127 launched in 1929; she had a maximum thickness of 4 inches (102 mm) at her belt. Her sister ships were all built with SA/H armour as well. The first battleship to receive SA/H armour protection was the South American Navy's Fast Battleship Chaco Austral FB-4z, launched in mid 1938; she had a maximum thickness of 13.5 inches (342.9 mm) at her belt. Her sisters were all completed with SA/H armour as well. SA/H Armour like Class SA/R is often greater than 3 inches but the use of SA/H Armour is different they mainly use them for certain parts of the barbettes as well the main belt armour and main battery turret sides. This is because SA/H Armour is much harder but comes at cost it more brittle than SA/R Armour largely due the 35% harden face which SA/R Armour dose not contain. The only other difference between the two types of armour is that SA/H Armour is much lighter then SA/R Armour. The most common method of mounting SA/H Armour is through the use of "tubs" or "plates". A tub is a large alloy box filled with molten metal, which is poured into a mould to form an ingot. The ingots are then cut up and used for various purposes including the manufacture of armour plates. Plates are usually cast from ingots rather than being made directly from molten metal. But SA/R Armour is prone to have cracks in cooling process it went to worse extant than other nations comparable armour plate expect Japan. South American Navy Studies shown SA/R Armour have an around 35-76% likeability of receiving cracks in forging process but it's not structural it's just for cosmetic appearance. SA/R Armour at end of WW2 was phased out while SA/R continued to be developed and forged for post-world ships.

#### **Table**

* TENSILE: 100-114
* YIELD: 73-92
* Y/T: .66-.81
* % EL: 23-29
* % RA: 62-72
* BRINELL: 650/220