And here it is, retrieved from the old Forum....
The Tonelero was a Brazilian Oberon class submarine, sister-boat to HMS Ocelot and was the last Oberon class boat to be completed for any navy.Tonelero was originally ordered from Vickers on 22nd May 1970 by the Brazilian Navy. She was laid down at Barrow-in-Furness on 18th November 1971 and was launched on 22nd November 1972.
The Chatham connection to this comes about now - During fitting out at Vickers, there was a serious fire aboard and the submarine was very badly damaged. So much so, that the decision was taken that the only way to salvage the boat would be to replace the damaged section of Pressure Hull completely. The only place in the country with the facilities, skills and tools to perform a repair on this scale was Chatham.
The Tonelero was towed to the naval base at Chatham. Once there, she was docked in No 5 dock. She was dismantled sufficiently to allow the centre 60ft section of her pressure hull to be cut out. The new Pressure Hull sections were built on No 7 slip and taken on low-loaders to No 5 Dock, where they were inserted into the hull. Once that was complete, the boat was completely rewired from scratch.
Repair sections leaving 7 slip

Repair sections arriving on site at 5 dock

Repair sections going into the hull

Tonelero left Chatham in April 1975 and returned to Barrow, where fitting out was completed and the boat was handed over to the Brazilian Navy.
As a result of this delay, Tonelero didn't commission into the Brazilian Navy until 8th September 1978, making her the final Oberon Class submarine to be built.
Tonelero went on to have a long career with the Brazilian Navy. She was given a mid-life upgrade in 1995 by HDW/Ferrostal. An unfortunate incident happened to the boat on Christmas Eve 2000, when she sank at her mooring in the Rio de Janiero naval base. All 9 crew members aboard at the time escaped safely. The boat was refloated on 8th January 2001. The cause of the sinking was put down to crew error. At the time, the boat was under repair, but has since been decommissioned.
Tonelero sunk:
