All info out about Indian rail gun developments are scattered & dis-organized. So let's summarize what we know so far about :
In the initial post I made an assumption that the EMALS related R&D work has kicked off the work in the rail gun department. That was a wrong assumption. Some files declassified in 2017 says work on rail gun have been ongoing since the late 80s & early 90s. In fact in 1994, a railgun with a 240 KJ capacitor fired 3.5 gm projectiles at 2 km/s. The gun had a square bore of unknown size.
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In 2018, DRDO in their Annual Report stated that 8 projectiles were fired from a railgun with 1.6 MJ capacitor. The capacitor bank was set up by combining four 400 KJ capacitor modules. The rail gun had a 12mm square bore, it could fire 8 gm projectiles at 1.5 km/s.
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Then DRDO decided to scale up. They developed a 30mm round bore railgun. This gun was officially named the Electromagnetic Rail Gun(EMRG). The other 2 guns had no official designations. Those were lab experiments conducted without much official budgets being put out for the experiments. The naming is important as it suggests official budgetary sanctions.
The EMRG in simulations :
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And the real thing :
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The eventual project goal is to fire a 1 kg projectile at 2 km/s from a 10 MJ capacity rail gun.
The 1 kg projectile probably wont be fired from a 30mm gun. That would make the projectile excessively long, thus reducing speed. A larger gun with a bigger bore dia would be needed.
This is where this recent simulation picture comes in. This talks about the R&D into design optimisation of a single & multi-turn rail gun :
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A single turn rail gun is the traditional rail gun we are familiar with. A multi-turn rail gun is a cross between a rail gun & a coil gun. The working principle of a multi-turn rail gun is that of a single turn rail gun & a coil gun combined. Since there are 2 different mechanisms for propelling the projectile working together, reaching any targeted speed takes a smaller barrel length than with one mechanism. This means the overall barrel length of a multi-turn rail gun will be smaller while providing the same performance as a single turn rail gun. This could make rail gun more practical to replace the traditional explosive driven guns in some applications. Naval main guns for example.
Here is a Russian research paper on multi-turn rail gun:
PDF | The multi-rail concept of railguns, the so-called multi-turn railguns, has been considered and dependences of their main parameters such as... | Find, read and cite all the research you need on ResearchGate
www.researchgate.net
Then comes the problem of power. If we have developed a 1.6 MJ capacitor bank we could simply bundle 10 of them & have a 16 MJ capacitor bank. That's more than the targeted 10 MJ capacity. Typical Indian "juggad" mindset. This is not the most efficient option but this will work.
If the Navy is the primary customer, we have to remember that on ships space is a luxury. Can't afford to carry a rail gun if it needs a massive space for capacitor banks. Luckily there has been some breakthroughs in super-capacitor tech in India.
Remember the Navy asking the NMRL to develop Air-Independent Propulsion(AIP) for the Kalvari class(P-75) submarines ?
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Well that R&D work had some spin-offs. NMRL managed to develop naval grade super-capacitors. A capacitor bank built with these super-capacitors might allow us to reduce the size of the bank.
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DRDO is also sponsoring academic institutes to do more R&D work in super-capacitors in hopes of further improvement of the tech. Some are already bearing fruits. Check post #2.
DRDO is taking a practical approach to weaponization of the tech. This is better than making a massive gun that's powerful but completely unpractical for real world use. I don't know how long before we have a practical working prototype. All the info here are at least a couple of years old.
