|Performance||Speed (max)||32 knots|
|Speed (cruising)||16 knots|
|Endurance||7,500 nm @ 16 knots|
|Armament||Guns||4 4.5 inch L50 Mark 6*, 16 37mm|
|Missiles||96 Jabiru Anti-aircraft, 64 MOG Anti-aircraft|
It was apparent that while the Indian Navy's surface action groups were potent anti-ship units, their air defense left much to be desired. The quadruple 37mm guns were essentially useless. Short-ranged and low-velocity they offered a defense against only the lowest-performance aircraft. Fortunately the Australian Navy had developed a family of anti-aircraft missiles called Jabiru. The basic Jabiru (Jabiru-I) was a medium-range weapon, effective out to about 40 miles. Equipped with a booster, it became Jabiru-II and had a range of over 100 miles. A third version was promised, Jabiru-III that would have anti-ballistic missile capability. The Indian Navy jumped in and bought the system. Another Australian system purchased at the same time was MOG, a short-range anti-aircraft missile. Together, the two Jabirus and MOG offered a fully-integrated, multi-layered area air defense system. This would be the heart of the Project 21 Godavari class air warfare destroyers
The Project 21 class destroyers were the largest of the Indian destroyers to date, displacing 5,250 tons Standard. The big, obvious, change was the installation of a large air search radar. The gun armament was reduced to four 4.5 Mark 6* in two twin turrets, while the 16 37mm guns in four quadruple mounts were retained as space and weight reservation with the intention that they would later be replaced by four twin 35mm BOER guns. The ship's real main armament was her missile battery. There were two twin Jabiru launchers, one forward, one aft, with 48 rounds (usually Jabiru I) in each magazine and two quadruple MOGs. The torpedo tubes were deleted but a helicopter hangar was built in aft. This was an innovative design with the launch pad being an elevator forming the roof of the hangar when in the extended position, the hangar being "sealed" by a roller door when the elevator was lowered.
Internally, the ship was revolutionary in another respect, she was diesel-gas turbine powered. Partly this was a result of the design being cramped and CODAG being less space-consuming but the real reason was political. The Indians were simply tired of importing ship machinery and wanted their own solution. India had already established a large-diesel industry for its civilian sector and a couple of big diesels made a very attractive powerplant. There are two problems; diesels like running at continuous speed, they dont like throttling up and down. Also, they didn't really deliver enough power to drive the ships at the required speed. At that point somebody has a brainwave; the Indians were already building industrial gas turbines for shore use and the same engines were also suited for naval applications so two gas turbines were added for boost. The old, early gas turbines were horribly expensive on fuel but they were only used for maximum speed at rare intervals. Mostly, the Project 21s cruised on their diesels. This had an interesting tactical implication; they were much more economical than steam turbine ships at cruising speed and much less economical at maximum speed so that caused tactical integration problems.
The first of the Project 21s was commissioned in 1964 but spent two years running missile and machinery trials before being accepted by the Navy. In 1966, both she and the Jabiru missile system were declared operational and with them, the Indian Navy finally came of age. The Indian Navy was now producing effective and capable ships of its own. It was set on its own design style and fashion and would follow its own path. Some of its future designs would be great successes, others embarrassing failures, but whatever else they would be, they were Indian designs.
Following the Pescadores Incident, the Godavari class were modernized. The 37mm quads were removed and replaced by quadruple MOG launchers while the deck carrying the original MOGs were enlarged and the MOG launcher there replaced by two twin 35mm BOER guns.