Alvand-class frigate

The Alvand class was originally a class of four frigates known as the Saam Class built for the pre-revolutionary Iranian Navy. They were renamed the Alvand Class after the revolution.

Three remain in service since the fourth was sunk by the US Navy in 1988 during the Iran-Iraq War.

Development & Building
The ships were built in the UK by Vosper Ltd and based on their Mark 5 design with the following arms & equipment:-


 * ASuW - 1 x quintiple Sea Killer Mk2 surface to surface missile
 * AAW - 1 x triple Sea Cat surface to air missile launcher
 * ASW 1x 3 barrelled Anti Submarine Mortar Mark 10 Limbo launcher
 * Guns - 1 x Mark 8 Mod 0 4.5 inch general purpose & 1 x twin 35mm Oerlikon AA
 * Electronics - Plessey AWS 1 air surveillance radar with on-mounted IFF; 2 x Contravenes Seahunter systems (For use with Sea cat, Sea Killer & the 35mm mount); Decca RDL 1 passive direction finding equipment

They were refitted in the UK shortly before the 1979 Iranian Revolution.

History
The ships were originally named after characters from Ferdowsi's Shahnameh, but after the Islamic Revolution they were renamed after mountains in Iran.

They saw action during the "Tanker War" phase of the Iran–Iraq War and proved effective against Iraqi forces. However after one was sunk, and other significant loses taken, during Operation Praying Mantis they saw little further use as the Iranian Navy proved no match for the US Navy.

Upgrades
The Sea Killer missiles were replaced by Chinese made C-802s in the 1990s, and the Sea Cats replaced by the addition of a 20mm AA gun leaving remaining ships with practically no effective anti-aircraft ability.

2 x triple 12.75 in torpedo tubes, 2 x 81 mm mortars & 2 x 0.50 cal machine guns were also fitted.

Successors
The Moudge class frigate is a modified Iranian-built version of the Alvand, with five either in service or building.