Visakhapatnam-class destroyer

The Visakhapatnam class (Project 15B) is a class of stealth guided missile destroyers currently being built for the Indian Navy. Based on the design, the Visakhapatnam class will be an extensively improved version. Ordered in 2011, the first ship is expected to be completed in 2018. Project 15B destroyers will feature enhanced stealth characteristics as well as incorporate state of the art weaponry and sensors including the long range Barak 8 surface-to-air missile. The keel of the first P-15B ship was laid in October 2013.

Design and construction
In January 2011, the Cabinet Committee on Security gave approval for a follow-on order of four more destroyers under Project 15B. Project 15B will retain the same hull as 15A Kolkata-class destroyers, but there will be significant changes in the superstructure that will improve the ship's stealth characteristics, it will incorporate a flush deck, include better acoustic signature and infrared signature reduction systems and more sophisticated weaponry such as: Nirbhay land-attack cruise missiles, supersonic anti-ship BrahMos and Barak 8-ER SAMs. They will also be capable of operating two helicopters simultaneously. Russia's Baltic Shipyard has been contracted to provide four sets of line shafts by 2017. Saint Petersburg's Northern Design Bureau was consulted during the design phase.

The Indian Navy has reported the ships will have a displacement of 7,300 tons (or 7,400 tonnes), however, other sources have stated 8,000 tonnes.

The total cost of the project is expected to be inr 300000000000. Build-time for Project 15B is expected to be shorter than the Kolkata class, as no major re-designing was to be done and would require only the time of ship building. Due to this, each warship is expected to save US$1 billion in costs. The design was finalized and the first destroyer, INS Visakhapatnam was launched on 20 April 2015 and is expected to join the Indian Navy by 2018, with the follow on ships being delivered biennially (every 2 years).

The P15-B stealth destroyers have been designed by Indian Navy's in-house unit Directorate of Naval Design. The ship's air defence capability, designed to counter the threat of enemy aircraft and anti-ship cruise missiles, will revolve around the vertical launch and long range supersonic surface-to-surface, air missile system. The system enables the ship to engage shore based and naval surface targets at long range, making it a lethal platform for strike against enemy targets. Four 30 mm rapid-fire guns will provide the ship with close-in-defence capability, while an MR gun will enable her to provide effective naval gunfire support. Indigenously developed twin tube torpedo launchers and rocket launchers will add punch to the ship's, anti-submarine warfare capability.

Project 15B vs Project 15A
The key difference between the Project 15A Kolkata-class destroyer and the Project 15B Visakhapatnam-class destroyer are not much since they both share the same hull design. Its however in the internal fitments that separates the 2 destroyer class.

1. The Visakhapatnam class will be armed with a 127 mm main gun while the Kolkata class are armed with 76mm Super Rapid Gun Mount (SRGM). Both classes share the AK-630 close-in anti-missile gun system. 2. The sonar of the Visakhapatnam class will be bow mounted and will feature a revised bridge layout. 3. The design of the mast, which features the main radar has been revised. The Visakhapatnam class will have a full-fledged Total Atmosphere Control System (TAC) to provide its crew greater protection in a nuclear, chemical or biological warfare scenario. 4. The new Visakhapatnam class also features a rail-less helicopter traversing system to secure the helicopter they carry in heavy sea conditions. 5. Central to the Visakhapatnam class is a network-centric layout. They are equipped with a Ship Data Network (SDN), an Automatic Power Management System and a Combat Management System. Essentially, all information critical for the operation of the warships during all operations is available to key officers through the SDN which the Navy describes as a data information highway. 6. The Project 15B Visakhapatnam-class destroyers maintain the same hull and propulsion package as the Project 15A Kolkata class. But Russia firm Northern Design Bureau, has been enlisted as design consultant to reduce the size of design's superstructure.