Indian Institute of Technology Madras (IIT Madras) has developed a ramjet-assisted artillery shell that can extend the firing range of existing 155 millimetre gun systems by nearly 50 percent without reducing lethality. The technology integrates a ramjet engine into a standard artillery shell, enabling sustained propulsion after the projectile exits the gun barrel.
The new design replaces the conventional base-bleed unit with an embedded ramjet, allowing the shell to maintain thrust during flight. This approach increases strike depth and operational flexibility while remaining compatible with current artillery platforms, avoiding the need for new gun systems or missile-based alternatives.
Trials conducted across multiple Indian Army artillery platforms demonstrated substantial range improvements. The Advanced Towed Artillery Gun System (ATAGS) showed an increase in range from about 40 kilometres to approximately 70 kilometres, while the K9 Vajra self-propelled howitzer’s range rose from around 36 kilometres to about 62 kilometres. The Dhanush artillery gun recorded an improvement from roughly 30 kilometres to close to 55 kilometres during trials.
The project was initiated in 2020 and carried out in collaboration with the Indian Army. It was led by Prof. P. A. Ramakrishna of IIT Madras, along with a multidisciplinary team comprising serving and retired military officers and academic researchers. The development programme included extensive gun and field trials to validate the concept under operational conditions.
The development team included Lt Gen P R Shankar (retd), Prof. H. S. N. Murthy, Prof. G. Rajesh, Prof. M. Ramakrishna, Prof. Murugaiyan, Lt Gen Hari Mohan Iyer (retd), Prof. Lazar C, Dr Yogesh Kumar Velari, Maj. Gen. Rajiv Narayanan and Prof. V R Lalithambika, bringing together academic expertise and operational experience.
Testing was conducted at the Deolali and Pokhran ranges, where the shell successfully demonstrated clean gun exit, stable flight characteristics and reliable ramjet ignition after launch. Officials involved in the programme said the trials confirmed that the additional propulsion did not adversely affect ballistic stability or safety during firing.
The developers said the ramjet-assisted shell is intended as an upgrade to existing artillery inventories, offering a means to significantly enhance range and effectiveness without changes to deployed platforms. Such upgrades could improve survivability by allowing artillery units to operate from greater stand-off distances while retaining conventional ammunition handling and logistics.
Manufacturing Perspective
From a manufacturing perspective, the ramjet-assisted artillery shell differs substantially from a conventional base-bleed round despite retaining the same external 155 millimetre form factor. A base-bleed shell uses a relatively simple rear-mounted unit that reduces aerodynamic drag and can be manufactured using established forging and machining processes with standard artillery-grade materials.
In contrast, the ramjet-assisted shell requires a more complex internal architecture to accommodate an air intake, combustion chamber and exhaust nozzle within the projectile body. This necessitates tighter machining tolerances, more advanced internal profiling and additional assembly stages compared with conventional shells.
Material requirements also differ, as sections of the ramjet shell must withstand higher thermal loads during sustained in-flight propulsion. This introduces the use of heat-resistant materials or coatings in specific internal components, along with enhanced quality assurance and non-destructive testing to ensure structural integrity, balance and reliable ignition after launch.
Despite the added complexity, the external dimensions of the ramjet-assisted shell remain unchanged, allowing it to be produced using existing artillery manufacturing infrastructure with targeted upgrades to internal processes rather than entirely new production lines.
Indian Institute of Technology Madras is one of India’s premier engineering and research institutions, with ongoing work across aerospace, defence, energy and advanced manufacturing technologies, often in collaboration with government agencies and industry partners.
