Battle of the Tonelero Pass

The Passage of the Tonelero
Part of the Platine War
Brazilian warships passing the Tonelero defences
Date 17 December 1851 Location Paraná River, Argentina 33°26′01″S 60°03′28″W / 33.43361°S 60.05778°W / -33.43361; -60.05778 Result Brazilian victory
Belligerents
Empire of Brazil	Argentine Confederation
Commanders and leaders
John Pascoe Grenfell	Lucio N. Mansilla
Strength
4 steamships 3 corvettes 1 brig 60 guns	2,000 16 guns
Casualties and losses
4 killed 5 wounded Corvette Dona Francisca hit by 3 cannon balls Steamship Recife heavily damaged Steamship Dom Afonso damaged Brig Caliope heavily damaged	Brazilian accounts: 8 killed 20 wounded Argentine accounts: 1 killed[1]

The Battle of the Tonelero Pass, also known as Passage of the Tonelero, was fought near the cliff of Acevedo, in the west bank of the Paraná River, Argentina, on 17 December 1851, between the Argentine Confederation Army commanded by Lucio Norberto Mansilla and warships of the Brazilian Imperial Navy led by John Pascoe Grenfell.