Riachuelo[[url=en.wikipedia.org/w/index.php?title=South_American_dreadnought_race&action=edit§ion=10]edit[/url]]

After selling Rio de Janeiro, the Brazilian government asked Armstrong and Vickers to prepare designs for a new battleship, something strongly supported by the Navy League of Brazil (Liga Maritima).^[​124] Armstrong agreed to construct the ship without any further payments from Brazil. They replied with at least fourteen designs, six from Vickers (December 1913 through March 1914) and eight from Armstrong (February 1914). Vickers' designs varied between eight and ten 15-inch and eight 16-inch guns, with speeds between 22 and 25 knots (the lower-end ships having mixed firing, the higher using oil), and displacements between 26,000 tonnes (26,000 long tons) and 30,500 tonnes (30,000 long tons). Armstrong took two basic designs, one with eight and the other with ten 15-inch guns, and varied their speed and firing.^{[​125][​R]}


While most secondary sources do not mention that Brazil ordered a battleship,^[​126] with the ship's entry in the warship encyclopedia Conway's All the World's Fighting Ships even remarking that "Brazil had not selected from the four design variations,"^[​127] the Brazilian government chose what was labeled as Design 781, the first of the eight 15-inch designs tendered by Armstrong, which also shared characteristics with the Queen Elizabeth and Revenge classes then being built for the United Kingdom.^[​128] They placed an order for one ship of this design, to be named Riachuelo, at the Armstrong Whitworth shipyard in Elswick on 12 May 1914.^[​129] Some preliminary gathering of materials was completed for a planned keel laying date of 10 September, but the beginning of the First World War in August 1914 delayed plans. Riachuelo was officially suspended on 14 January 1915 and canceled on 13 May 1915.^[​130]