Niterói-class frigate

The Niterói-class frigates are a class of frigates of the Brazilian Navy.

History
The Niterói class were designed and built by the British shipyard Vosper Thornycroft (VT) in the 1970s. These frigates were designated the Mk 10 by Vosper Thornycroft and are the largest of a series of ships built by that shipyard for both foreign buyers and the Royal Navy.

All of them were extensively modernized between 1996 and 2005 under the 'ModFrag' program. The projected completion was 2001, but due to lack of funds and sea trials to verify the new software, the entire program had been slipped to 2005.

A total of six ships were built. Two of the anti submarine (ASW) and both of the general purpose (GP) version were built in England. The remaining two ASW ships were built at the Arsenal da Marinha in Rio de Janeiro with assistance from VT. The ASW ships had an Ikara missile launcher in Y position aft of the flight deck. This was removed as part of the modernisation programme. The GP ships had a second 4.5 in gun in "Y" position. A seventh ship was built as the navy's main training unit. The ship is identical to the other ships of the class, but is not fitted with weapons or sensors.