NEW DELHI: The Indian Army is on the cusp of becoming the world’s first armed force to operationally deploy ramjet-powered artillery shells for its 155 mm guns. The advanced technology, developed in collaboration with the Indian Institute of Technology (IIT) Madras and with support of Army Technology Board (ATB), is now under trial.Ramjet propulsion is not new and has been used in missiles worldwide. However, applying the technology to artillery shells is a revolutionary step.Professors P A Ramakrishna and S Verma from IIT Madras’ Department of Aerospace Engineering co-developed a ramjet-powered artillery shell after years of research. The technology, developed under the Atmanirbhar Bharat initiative, is designed to significantly extend the reach of standard tube artillery.Prof Ramakrishna recently explained that a ramjet operates as an air-breathing engine that does not require turbines or compressors. It relies on the shell being launched to speeds of approx Mach 2 using an artillery gun. At this velocity, air entering the engine is naturally compressed, fuel is ignited and thrust is produced, which allows the shell to maintain propulsion and significantly extend its range.“Being an air-breathing engine, ramjet has higher specific impulse (ISP) (> 4000 N s/kg) compared to that of a solid rocket (~2500 N s/kg) and, therefore, provides much higher overall impulse to the shell for the same mass of propellant,” the IIT-M research paper said. One of the key challenges IIT-M team faced was using ramjet to have high combustion efficiency with restricted secondary combustor length. However, the team managed to overcome this obstacle.The technology promises to extend the range of conventional artillery shells by 30% to 50% while maintaining their destructive power. By integrating ramjet technology into 155 mm shells, the Army obtained the ability to strike deeper targets with greater effectiveness. Developmental trials are currently under way, with successful tests already conducted at the Pokhran field firing ranges. These trials have demonstrated the feasibility of retrofitting ramjet modules onto existing 155 mm shells, meaning the technology can be applied across the Army’s current inventory without requiring entirely new ammunition designs.Once the ramjet artillery shell technology is ready for induction, it can be used in any of the Army’s artillery systems, including on the US-imported M777 ultra-light howitzer.
