India-made 'Surat' and 'Udaygiri' warships

Context

Recently, two indigenous warships of the Indian Navy, Surat, a Project 15B Destroyer and Udaygiri, a Project 17A Frigate, were launched concurrently at Mazgaon Docks Limited, Mumbai.

About Surat

• INS Surat is the fourth and the last ship of the 7,400-tonne Project 15B Indian Navy Destroyers. 
• These are called the Visakhapatnam class after the lead vessel INS Visakhapatnam. 
• The Destroyer has been named after Gujarat's commercial capital- Surat, which has a rich maritime and ship-building history. 
• The Indian Naval Destroyers are named after Indian cities as per the naval tradition. It began with Project 15, under which three destroyers were built: INS Delhi in 1997, INS Mysore in 1999 and INS Mumbai in 2001.
• Project 15 was followed by the three-destroyer Project 15A, under which INS Kolkata was commissioned in 2014, INS Kochi in 2015 and INS Chennai in 2016.
• ‘Surat’ is the fourth ship of Project 15B Destroyers which heralds a significant makeover of the P15A (Kolkata Class) Destroyers and is named after the commercial capital of the state of Gujarat and also the second largest commercial hub of western India after Mumbai.
• Project 15B: The Project 15B class of ships are the next generation stealth guided missile destroyers of the Indian Navy being built at the Mazgaon Docks Ltd, Mumbai.
• Under project 15-B, the first destroyer of the project INS Visakhapatnam was commissioned in November 2021, while the second INS Morm­ugao and third INS Imphal have been launched; they are at different stages of trials.
• INS Surat has been built using Block construction methodology that involves hull construction in two different locations and then joint together at one hub. 
• While INS Morm­ugao will be commissioned in 2022, INS Imphal will be commissioned in 2023 and INS Surat is likely to be commissioned in 2024, all at one-year intervals. 
• Project 15B is expected to cost a total of Rs 35,800 crore, Rs 8,950 crore per vessel.

About Udaygiri

• ‘Udaygiri’, named after a mountain range in the state of Andhra Pradesh, is the third ship of Project 17A Frigates.
• It is named after a mountain range in Andhra Pradesh, India. 
• The INS Udaygiri frigate will be more advanced than the P17 Shivalik Class Frigates with advanced weapons, improved stealth features, sensors and platform management system.
• Under the P17A program, a total of seven ships, with 04 at MDL and 03 at GRSE are under construction.
• Both 15B and P17A ships have been designed in-house by the Directorate of Naval Design (DND). 
• The Project 17 has yielded three frigates so far, INS Shivalik in 2010, INS Satpura in 2011 and INS Sahyadri in 2012.
• A total of seven ships will be launched under the P17A programe, out of which O3 and O4 are under construction. 
• These frigates are reincarnations of the six-ship Leander-class or the Nilgiri-class, which included -INS Nilgiri (1972- 1996), INS Himgiri (1974-2005), INS Udaygiri (1976-2007), INS Dunagiri (1977-2010, INS Taragiri (1980-2013) and INS Vindhyagiri (1981-2012).