The Brazilians broke through the river defences at Curupaity during daylight on 15 August 1867 with "Barroso", "Tamanadaré", and eight other ironclads. The ships were hit 256 times, but not seriously damaged, and only suffered 10 killed and 22 wounded. They repeated the operation again on 9 September. On 19 February 1868 six Brazilian ironclads, including "Barroso", steamed past Humaitá at night. Three river monitors, , and were lashed to the larger ironclads in case any engines were disabled by the Paraguayan guns. "Barroso" led with "Rio Grande", followed by "Bahia" with "Alagoas" and "Tamandaré" with "Pará". "Barroso" continued upstream with the other undamaged ships and they bombarded Asunción on 24 February. On 23 March "Rio Grande" and "Barroso" sank the steamer "Igurey" and both ships were boarded by Paraguayan soldiers on the evening of 9 July, although they managed to repel the boarders.