Minas Geraes Class Battleship - Specifications

Specifications

The two ships of the Minas Geraes class were 543 feet (166 m) overall, 530 feet (160 m) at the waterline, and 500 feet (150 m) between perpendiculars. They had a beam of 83 feet (25 m), a mean draft of 25 feet (7.6 m), a maximum draft of 28 feet (8.5 m), a normal displacement of 18,976 long tons (19,281 t), and a displacement of 20,900 long tons (21,200 t) at full load. At the beginning of their careers, the ships were crewed by about 900 men.

Minas Geraes and São Paulo were originally armed with twelve 12-inch/45 caliber, twenty-two 4.7-inch/50 caliber, and eight 3-pounder naval guns. The main battery was arranged with four superfiring turrets, two each fore and aft, and two placed en echelon. The 4.7-inch secondary guns were placed in casemates along the side of the ship.

The propulsion of the two ships was provided by Vickers vertical triple expansion engines instead of the steam turbines being used to power most contemporary dreadnoughts. Eighteen boilers provided power to the engines, which in turn rotated the two three-bladed propellers with 23,500 shaft horsepower. Their designed top speed was 21 knots (24 mph; 39 km/h), though this was frequently unattainable in their later careers owing to substandard maintenance and neglect. The ships could carry 2,350 tonnes (2,310 long tons) of coal and 400 tonnes (390 long tons) of oil, and their original endurance was 10,000 nautical miles (12,000 mi; 19,000 km) when traveling at 10 knots (12 mph; 19 km/h). During her trials, Minas Geraes was able to steam at 22.29 knots (25.65 mph; 41.28 km/h).

The main armor belt was nine inches (230 mm) thick, but narrowed to six and three inches (150 and 76 mm) closer to each end of the ships. The barbettes were protected by nine-inch armor, while the turret had a twelve-inch (300 mm) front, eight-inch (200 mm) sides, and a two- to three-inch (51 to 76 mm) top, and the conning tower had twelve-inch armor. The deck armor had multiple decks of one-and-a-half to two inches (38 to 51 mm), one inch (25 mm), and one inch.

South American dreadnoughts
From The Naval Annual (1915)
The Minas Geraes class was designed, constructed, and completed before the other South American dreadnoughts, but was smaller and not as well-armed. Two later dreadnoughts, Rio de Janeiro and Riachuelo, were planned to rectify this, but the former was sold to the Ottoman Empire amid falling government revenues, and the other was not laid down when the First World War broke out and all British shipbuilding for foreign countries was suspended.
The Rivadavia class were the second dreadnought class purchased by a South American country and the only ones to not be built by a British company. Ordered in response to the Minas Geraes class, they mounted the same-size main battery as the Brazilian ships (12-inch), but the Argentine ships were much larger and significantly better-armored.
Almirante Latorre was the last South American dreadnought built, and was larger and better armed than her counterparts. The more efficient arrangement of the five 14-inch turrets, with all mounted on the centerline rather than en echelon, allowed the main battery to fire on a single broadside without damaging the ship.

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