Brazilian Battleship Minas Geraes - Inter-war Period

Inter-war Period

São Paulo's refit was finished on 17 January 1920 and she returned to Brazil; on 15 July Minas Geraes departed for New York for her own refit. Beginning on 22 August, the day she arrived, and finishing on 4 October 1921, the battleship was dramatically modernized, with Sperry fire-control equipment and Bausch and Lomb range-finders for the two superfiring turrets fore and aft. A vertical armor bulkhead was fitted inside the main turrets, and the secondary battery of 4.7 in (120 mm) guns was reduced from 22 to 12; five guns in casemates were removed from each side. A few modern AA guns were fitted: two 3"/50 caliber guns from Bethlehem Steel were added on the aft superstructure, 37 mm (1.5 in) guns were added near each turret, and 3-pounder guns were removed from the tops of turrets.

In July 1922, Minas Geraes joined São Paulo in helping to quash the first of the Revolução Tenentista (English: Tenente revolts), in which the garrison of Rio de Janeiro's Fort Copacabana rebelled and began bombarding the city. São Paulo shelled the fort, and the rebels surrendered shortly thereafter; Minas Geraes did not fire her guns.

In 1924, Minas Geraes was involved in another mutiny, but remained on the side of the government. First Lieutenant Hercolino Cascardo, seven second lieutenants and others commandeered São Paulo in Rio de Janeiro's harbor on 4 November 1924. Their goal was to force the government to release prisoners who had participated in the 1922 Tenente revolts from confinement aboard the prison ship Cuibaba; the mutineers' demands were not met. São Paulo's boilers were then fired, and she "steamed menacingly" around Minas Geraes in an attempt to entice her and other ships to join the rebellion. São Paulo was only able to sway the crew of one old torpedo boat to her cause. Her crew, angry that Minas Geraes would not join them, shot a six-pounder at Minas Geraes, wounding a cook. The mutineers then sailed out of the harbor, exchanging shots with forts at the entrance along the way, and set course for Montevideo, Uruguay. The condensers failed along the way, and they reached Montevideo on 10 November making only 9 knots (10 mph; 17 km/h). The rebellious members of the crew disembarked and were granted asylum, while the remainder re-hoisted the colors of Brazil.

Between June 1931 and April 1938, Minas Geraes was totally reconstructed and modernized at the Rio de Janeiro Naval Yard. She was converted from her old coal–oil combination to all-oil firing. All eighteen of the original Babcock and Wilcox boilers were removed in favor of six new John I. Thornycroft & Company boilers. The former No. 1 boiler room and all twelve of the side coal bunkers were converted to fuel oil storage tanks; the upper coal bunkers were removed. In addition, Minas Geraes' dynamos were replaced with new turbogenerators. The most striking aesthetic change was the trunking of the boiler uptakes into a single funnel. The fire-control systems that had been fitted after the First World War were also modernized in favor of Zeiss range-finders. The guns were overhauled; two extra 4.7 in (120 mm) guns were added (making 14 total), and six 20 mm (0.79 in) Madsen guns were installed, including two on the top of 'X' turret. The maximum elevation of the 12-inch guns was upped from 13° to 18°.