Trajano was built at the Arsenal de Marinha da Corte in Rio de Janeiro between 1872 and 1873. Its name was given by request of emperor Pedro II as a tribute to naval engineer, who was the ship's designer. It was laid down on 27 May 1872, with the presence of the emperor. It was launched on 12 July 1873, also with the presence of the emperor, the officership and about a thousand spectators, being incorporated into the navy a few days later on 17 July 1873.[1]
The ship was built of wood and steel, displacing a total of 1392 tonnes. It measured 200 ft in length, 31 ft of beam, 15 ft of draft and 19.5 ft in height. It was powered by John Penn and Sons steam engines and sails, which produced a total of 2400 HP propelling the ship to a maximum speed of 12 knots. Trajano was armed with three 70-pounder Whitworth guns and other smaller guns of unspecified caliber.
With the outbreak of the Navy Revolt, promoted by units of the Brazilian Navy against the government of the newly proclaimed Brazilian Republic after the 1889 Coup, Trajano was seized by the rebels, taking part in the revolt in 1893 and bombing fortified positions in Rio de Janeiro. In this period, it was temporarily renamed to Toneleiros. The ship was decommissioned in 1906 by Notice No. 499 of April 11.