Well , actually the real reason why we order in batches of 3 is coz
1:In case of frigates the reason was delay, Indian Shipyards take 10-12 yrs to deliver 3 frigates compared to 6 yrs taken by Russia and China
Let me give you the an example , Godavari class were sanctioned in 1971 , Construction began in 1973 and last frigate were delivered in 1988 , 17 yrs after the placing of order
Same was the case with Brahmaputra class where order were placed in 1988 , and last ship was inducted in 2004 , 16 yrs after placement of order, Infact by the time Brahmaputra class was inducted , the world had moved on to stealth frigates .
Foreseeing the change in technology , India ordered the Talwar class in 1996 , Which were inducted in 2002-04 , A record of within 8 yrs of placing the order
Things have improved in Indian Shipyards , by the time shivalik class was ordered in 2001
This class has completed induction in 11 yrs with induction of INS Sahyadri on 21 July 2012 , now compared to 16-17 yrs it took previously , so its a big improvement
But Indian Navy was again fearing a delay and uncertainty related to capability of Shivalik class , so they ordered another batch of Talwar class in 2006.
But with Shivalik having more than impressed the Indian Navy , and proving to be far more capable than envisioned , so they have placed an order for 7 P-17A frigates
But because of their fear of Delays by Indian Shipyards , they are again looking to hedge their bets by Placing the order for Kirvak IV Frigates which are an improvement over the TALWAR CLASS , This is also the reason why P-17A was trimmed from 9 to 7 , coz Navy feels that it can get 3 Kirvak IV Frigates out of the savings made by not ordering 2 more P-17A Frigates
Also going by the price of P-17A , it seems that the 2.6 Billion USD , IN will save by scraping 2 P-17A , can easily pay for the 3 , 4500 Ton Kirvak IV Frigates
