Rolls-Royce offers electric propulsion to Indian Navy
MT30 gas turbines on the HMS Queen Elizabeth are the core of electric pitch

After going from sail to coal and steam and to oil, navies around the world are increasingly embracing the inevitable next big transition: electric propulsion, something that enables a wider-ranging, more reliable and efficient footprint with greater endurance and without a loss in firepower.

And like the transition from sail to steam, which went through a hybrid-model period in the mid-19th century out of necessity, where steam supplemented sail simply because it couldn’t yet beat its endurance, propulsion today has seen the emergence of another hybrid model, where oil-based fuels generate power to turn electric motors, power the ship and charge batteries. Again, batteries of acceptable weight and volume today simply do not have the endurance required for maritime voyages without being constantly recharged by diesel generators and gas turbines. But the leap in efficiency and power density make this hybrid model the inevitable propulsion around which navies such as India’s will look to design their future warships.

The United Kingdom’s Rolls-Royce, a standard for elegance in automobiles through the 20th century, took the opportunity during the visit of the HMS Queen Elizabeth Carrier Strike Group in Mumbai to demonstrate their MT30 engine to the Indian Navy. Based on the Rolls-Royce Trent 800 aero engine that powers the Boeing 777, the MT30 is a marine gas turbine engine, two of which propel the HMS Queen Elizabeth aircraft carrier, forming part of its Integrated Full Electric Propulsion (IFEP) along with four Wärtsilä diesel engines coupled to GE motors.

This IFEP reduces the requirement for clutches and gearboxes, feeding energy into the electric motor, resulting in more efficient and cleaner power generation, savings in space and weight and importantly, making warships much quieter than those powered by traditional engines.

The HMS Queen Elizabeth is propelled by the IFEP system incorporating ‘two MT30 marine gas turbine alternators per ship, rated at 36MW, with the power to propel these vessels beyond 25knots’, according to Rolls-Royce. Their elevator pitch emphasises the MT30’s power density, ‘significantly reducing the number of gas turbines required to power advanced naval platforms’, guaranteeing ‘its power throughout the 50-year service life expectancy of the ship’.

And although this isn’t something that can be done overnight, or even in a couple of years — beginning such a transition alone could be a decade-long prospect, given the service life of naval vessels and the long lead time for warship construction — president of Rolls-Royce for India and South Asia, Kishore Jayaraman, thinks there is strong interest from the Indian Navy in IFEP.

“The enthusiasm and the passion that they have displayed in terms of wanting to know more to figure out how this can be implemented and taken forward, shows there’s a lot of interest. Now for converting that interest into a project — there is a little bit of a distance because of a multitude of things. But at the end of the day, no one has ever not wanted to talk about electric in any of these meetings. Even if we do gas propulsion concepts – they ask: ‘what is your positioning in terms of electrification and hybrid solutions’,” he said.

Pointing to elements of recent Indian Navy Requests for Information (RFIs), senior vice president for Rolls-Royce’s defence business in India and South East Asia, Abhishek Singh said, “You’ll see that there is this element of — if not full electric, at least a hybrid electric solution being considered and it seems to be aligned to the aspirations that we see with the Indian Navy.”

Singh thinks the opportunity for Rolls-Royce ranges from the MT30 and MT10 gas turbines to the the AG9140 and AG9160 generators, propellers and a low voltage electric power distribution system (the one on the HMS Queen Elizabeth can power 5,000 homes). These, he said, ‘could be potential offerings that could be put on the next generation destroyers, frigates or even IAC2 (Indigenous Aircraft Carrier 2)’.

Two MT30 gas turbines and RR4500 generators also power the U.S. Zumwalt-class stealth, guided missile destroyers with a total output of 78MW.

Rolls-Royce has already signed a Memorandum of Understanding with India’s Hindustan Aeronautics Limited (HAL). “We signed an MoU with HAL as well at the beginning of this year to work with them on the package for integration and after-market support for anything that we do with MT30 in India,” said Singh.

Rolls-Royce is already looking for options to localise the engine.

“We have looked at how we can provide the after-market support, beginning with a transfer of technology package in India. We want to allocate a significant workshare to package the complete MT30 engine in India and install and integrate it,” said Singh, adding they were also looking for potential components suppliers for after-market requirements, as well as potential exports.

Jayaraman thinks that any Indian interest in IFEP into a project would have to happen right at the beginning. “It happens from Day Zero,” he said.

“It is going to happen at the conceptual stages. When they decide I want this ship — they’re going to say: ‘this is the kind of propulsion I want’. And that’s when the conversation will happen with the propulsion designers and manufacturers. We’ve already shared ideas about the possibilities with the Indian Navy,” said Jayaraman, explaining that IFEP isn’t something that is an optional plug-and-play propulsion set and has to be integral early in the design phase at the stage of concept and definition.

“There would be significant design differences. Propulsion is propulsion, for which you have to create the necessary thrust to move the vessel forward — that’s the basic concept. But then from the concept stage when you start building on it, all your components will be different. Because the thrust is going to be different which says the capability, the mechanical components, the bearings, the load — everything is going to be different. So there are a lot of design components that will have to go into it right from the beginning,” he said.

But while Jayaraman knows such a transition will ultimately depend on Indian strategic priorities, he’s confident IFEP will find power Indian warships. “It all depends on India’s future naval strategy. We’ve heard of plans for a second aircraft carrier, more frigates, destroyers and submarines. The exact numbers will depend on the navy but I think there’s a sizeable proposition and a lot of opportunity in India,” he said.