History

The Niterói Class Frigates were designed and built by the British shipyard Vosper Thornycroft in the 1970's. These ships were designated 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, also known as the Type 21 frigate

Type 21 frigate

The Type 21 frigate or Amazon-class frigate was a Royal Navy general-purpose escort designed in the late 1960s, built in the 1970s and that served throughout the 1980s into the 1990s.-History:...

, or Amazon class.

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, four of an anti submarine version built in England. These ships had an Ikara

Ikara (missile)

The Ikara missile was an Australian ship-launched anti-submarine missile, named after an Australian Aboriginal word for "throwing stick". It launched an acoustic torpedo to a range of , allowing fast-reaction attacks against submarines at ranges that would otherwise require the launching ship to...

missile launcher in Y position aft of the flight deck. This was removed as part of the modernisation programme. The remaining two general purpose ships were built at the Arsenal da Marinha no Rio de Janeiro with assistance from VT. These ships had a second 4.5 inch 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.

Ships

Pennant number	Name	Launched	Completed	Type	Current status
F40	Niterói	8/2/74	20/11/76	ASW	In service
F41	Defensora	27/3/75	5/3/77	ASW	In service
F42		15/4/76	31/3/78	ASW	In service
F43	Liberal	15/4/76	31/3/78	ASW	In service
F44	Independência	2/9/74	3/9/79	GP	In service
F45	União	14/3/75	17/9/80	GP	In service
U27	Brasil	23/9/83	21/8/86	Training	In service