[custom_adv] A massive order was made by the Iranian government in an attempt to modernize the Iranian Imperial Navy and give it capability to patrol the Caspian Sea, Persian Gulf and Indian Ocean. The Iranian Navy had placed an order for 4 Kidd-class destroyers equipped with Standard missiles, Harpoon missiles, Phalanx CIWSs and Mark 46 torpedoes, 3 used retrofitted Tang-class submarines (these were transferred rather than sold to Iran from the American military) equipped with sub Harpoon missiles. In addition the navy sought to acquire 39 Lockheed P-3 Orion maritime reconnaissance planes for ocean surveillance and anti-submarine warfare. [custom_adv] Unlike the air force the Imperial Iranian Navy did not solely rely on American equipment and used a wide variety of suppliers. From Germany, Iran ordered 6 diesel type 209 submarines due to arrive in 1980 designed to protect Iran in the Indian Ocean. vicinity. [custom_adv] From Italy, Iran ordered 6 Lupo-class frigates, capable of anti-submarine warfare and outfitted with Otomat missiles. In 1978 Iran ordered 8 Kortenaer-class frigates from the Dutch, each one equipped with Mk. 46 torpedoes, Harpoon missiles and Sea Sparrow anti-aircraft missiles. In the same year Iran sought to order a further four Bremen-class frigates (similar in design to the Korteaer class). [custom_adv] Iran had entered discussions with Great Britain as early as the late 1960s to purchase a nuclear powered aircraft carrier that would give Iran amphibious attack capabilities in the Indian Ocean. While initially interested in purchasing one CVA-01 aircraft carrier, which was later on cancelled by the British, Iran expressed interest in the Invincible-class aircraft carriers. [custom_adv] Talks were in place for Iran to purchase 3 modified versions of these carriers however no official record stands to prove that such an order was placed. From France, Iran ordered 12 La Combattante IIa-class fast attack craft equipped with Harpoon missiles. Of this order, approximately 6 were delivered and the subsequent 6 cancelled. [custom_adv] During this same time-frame in the 1970s the Imperial Iranian Army was making several advancements and placing massive orders to keep up with other divisions of the military. [custom_adv] To reinforce the ground troops the Iranians ordered 500 M109 howitzer's, 455 M60 Patton A3 tanks were ordered from the Americans. The largest order was placed from the British for 2000 Chieftain tanks, which had been specifically designed for the Iranian Army. [custom_adv] Some other major equipment on order included hundreds of Russian BMP-1 outfitted with anti-tank missiles. A massive order was made by the Iranian government in an attempt to modernize the Iranian Imperial Navy and give it capability to patrol the Caspian Sea, Persian Gulf and Indian Ocean.