P-77 SSN: Indian Nuclear Attack Submarine Project

[Fatalis]

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Just an observation of mine. The older S5 model looks similar to the Type 094 SSBNs of PLAN, specifically the hump and transition from hump - upper hull. Any opinions?

I also feel like the number of missiles might have gone up from 12 to 16 just from looking at the sheer length of the compartment.

 

[Gessler]

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Just an observation of mine. The older S5 model looks similar to the Type 094 SSBNs of PLAN, specifically the hump and transition from hump - upper hull. Any opinions?

It's what @SwordOfDarkness said.

That's the only way to fit large missiles into a hull this size.

The Chinese weren't the first to do it either. You can find similar, large humps on the Soviet Delta-class SSBNs as well.

IN seems to have accepted the cost of larger sub to have better performance in S5.

Personally, I don't think so. Going for a larger beam (diameter of hull) would mean essentially going back to the drawing board & starting from square one. That would induce years of delay.

I think the reason why we largely eliminated the hump is because of advancements in missile technology i.e. we're able to reach the same range with same payload as before, but with a shorter missile. Which in turn must have informed submarine design.

The beam of Ohio and Delta IV is not that different (13.0m vs 12.3m = 0.7m diff), but the Ohio's Trident-II missile is much shorter than R29RMU Sineva (13.6m vs 14.8m = 1.2m diff). The difference amount of 0.5m is largely the reason why Delta (pic above) needs the huge hump while Ohio's hump is comparatively more streamlined:

Missile dimensions are key to determining the hump. Where the missile is even shorter (like France's M51 which is only 12.0m) the hump on Triomphant is totally non-existent:

When we compare the original Agni-V tested 12 years ago to the new MIRVed version you'll see that it's actually shorter (even accounting for the blunt nose, look at the height of the upper black interstage):

This is despite the fact that if anything, the MIRVed version actually has to carry heavier payloads. There's no doubt that India's solid-fuel propulsion tech has advanced considerably over the last decade. Not to mention progress in composite stages, which reduce weight & in turn reduce amount of fuel needed.

What we're seeing in the S5's design evolution is likely a result of that progress actually.