Indian Navy ‘Prioritizes’ Electric Propulsion For Large Warships Before Nuke Propulsion For Aircraft Carriers

The Indian and UK Defense Ministries signed a Statement of Intent (SoI) on November 28 in Portsmouth regarding Cooperation on the Design and development of Integrated Electric Propulsion (IEP) Systems.

According to an Indian MoD press release, “The SoI would serve as a broader framework intended for cooperation in the co-design, co-creation, and co-production of Electric Propulsion capability for future naval ships. The Landing Platform Docks, planned to be built at an Indian Shipyard, are envisaged to have a Full Electric Propulsion System.”

IEP has been described as the “direction of future naval propulsion” for surface ships.

Several nations have deployed IEP warships. These include the Royal Navy’s Type 45 destroyers and Queen Elizabeth-class Aircraft Carriers, the US Navy’s Zumwalt-class Destroyers and America-class Amphibious Assault Ships, China’s Type 055 Destroyers, and the French Navy’s Horizon-class Frigates and Mistral-class Amphibious Assault Ships.

Most current-generation Indian warships use traditional propulsion systems, such as gas turbines, diesel engines, or combined gas turbine and diesel engines.

Ministries of Defence of India and UK in Portsmouth on November 28, 2024. Credits PIB.

The Indian Navy’s indigenously built aircraft carrier INS Vikrant uses a diesel-electric IEP system for propulsion, while the Visakhapatnam-class (P-15B) stealth destroyers employ hybrid propulsion systems.

However, the propulsion systems fitted on the above ships were imported.

The Indian Navy is keen to use indigenously built IEP for its next-generation warships because IEP offers better stealth due to significant noise reduction, increased maneuverability, lower fuel consumption, higher speed, and reduced environmental risks.

In 2019, it was reported that the Indian Navy had set up a 5 MW electric propulsion system from Siemens of Germany at the onshore training establishment INS Valsura at Jamnagar in Gujarat to train naval engineers to operate electric-drive ships.

British Collaboration

In October 2019, the UK offered India IEP systems under the Make-in-India program.

In November 2019, the Royal Navy’s Type 45 destroyer HMS Defender made a port call at Mormugao Port Trust in Goa. It was reported that at least 15 officers from the Indian Navy visited HMS Defender and interacted with officials from the foreign defense manufacturers who were present on the vessel.

In April 2022, Bharat Heavy Electricals (BHEL) and GE Power Conversion signed a memorandum of understanding (MoU) to assist BHEL in developing an IEP System to power Indian Navy warships.

France-based GE Power Conversion is a world leader in electric propulsion. Its equipment is installed on some of the latest US Navy and Royal Navy platforms, including the Queen Elizabeth class of aircraft carriers.

A British-French consortium has reportedly offered India an IEP based on Rolls-Royce gas turbines, GE Energy alternators, and Rolls-Royce propellers. The alliance between GE Power Conversion and BHEL is expected to build the alternator in India.

Electric Propulsion

Warships are increasingly equipped with IEPs instead of traditional gas turbines because IEP offers several key advantages. These include:

  1. Improved Fuel Efficiency

  2. Flexibility in Power Distribution

  3. Reduced Acoustic Signature

  4. Enhanced Reliability and Maintenance

  5. Design Flexibility

Unlike traditional propulsion systems, which use mechanical energy directly to drive shafts and propellers that power a ship, IEP systems use traditional propulsion systems to generate electrical energy. In turn, the generated electrical power is used to power ship sensors and systems and drive shafts and propellers that power a ship.

IEP systems typically comprise diesel engines, gas turbines or nuclear reactors to run electric power generators. The electric power generated goes through power conversion systems such as transformers, rectifiers, and inverters into a Power distribution system that distributes the power to propulsion, weapon systems, and other ship functions.

Electric power diverted to propulsion drives electric motors that convert electrical energy back into mechanical energy to drive the ship’s propellers.

Advantages Of IEP

IEP allows engines to operate optimally regardless of the ship’s speed. This improves fuel economy, especially at lower speeds, compared to gas turbines, which are less efficient at lower loads.

IEP facilitates better power distribution between propulsion and onboard systems, such as radars, weapons, and sensors. This is particularly critical for future warships equipped with power-hungry systems like railguns and laser weapons.

IEPs are quieter than gas turbines. They have fewer mechanical components, like reduction gears, which are prone to wear and maintenance. This increases system reliability and reduces long-term operational costs.

IEP allows greater freedom in ship design. Propulsion systems are no longer constrained by the need to align engines with propellers, enabling better utilization of internal space.

For example, in the Royal Navy’s Type 45 destroyer HMS Defender, power generation is installed on upper decks, not at the same level and near the gearbox and the propeller. This system saves space, is easier to upgrade, and is flexible.

Indian Navy Plans

Starting with Landing Platform Dock (LPD) amphibious warships – which can operate helicopters and drones and carry amphibious vessels, troops, and land vehicles – the Indian Navy wants to use IEP on its next generation of P-18 destroyers and aircraft carriers of the future.

In August 2021, the Indian Navy issued a Request for Information (RFI) from Indian shipyards to procure 4 Landing Platform Docks (LPDs) from Indian Shipyards.

The LPDs feature a flight deck for operating aircraft, a dock well at the lower level to carry amphibious vessels, and space for land vehicles like battle tanks and armored vehicles. The ships can partially submerge the well dock by ballasting the stern of the ship to facilitate the docking and undocking of amphibious vessels.

India currently operates one LPD, the INS Jalashwa, an Austin-class amphibious transport dock procured from the United States.

The RFI stipulates a maximum length of 200 meters, a maximum draught of 8 meters, and IEP.

The LPDs must be able to sustain a speed of 20 knots or above and should cruise at 14 to 16 knots. They should also be able to provide logistical support to the troops for 60 days.

  • Vijainder K Thakur is a retired IAF Jaguar pilot, author, software architect, entrepreneur, and military analyst. 
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