this post was submitted on 14 Aug 2023
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Showerthoughts

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Watching TV shows or movies that display Russia as a military superpower is almost surreal nowadays. (self.showerthoughts)
submitted 1 year ago by ramble81 to c/showerthoughts
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Was just watching Jack Ryan Season 3 and seeing the display of force and their movements causes some interesting dissonance given what we know now.

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[–] [email protected] 7 points 1 year ago* (last edited 1 year ago) (1 children)

the countries that still use those just don’t have enough money to maintain a nuclear sub fleet

IRC the French have at least one diesel sub, the SMX-Ocean Range 30,000km.

They also have modern battery tech, the money and the tech to maintain/build nuclear subs. They have existing nuclear subs. The SMX-Ocean is actually quite modern. 2017 I think. Certainly more modern than most existing nuclear subs.

it’s cost efficiency not “better”.

Here's an article which explains why modern diesel subs can be quieter than nuclear subs:

https://navalpost.com/nuclear-submarines-diesel-electric-submarines-noise-level/

they are slow compared to nuclear subs

I googled. 20 knots for the SMX-Ocean. 25 for France's nuclear subs. Not a huge difference.

[–] DigitalTraveler42 0 points 1 year ago* (last edited 1 year ago) (1 children)

IRC the French have at least one diesel sub, the SMX-Ocean Range 30,000km.

Wait so you honestly think they're going 30,000 km on battery power?

Do you not get that submarine combustion engines are just like car combustion engines? You generate power through the engines and that power is stored on battery to power the electrical systems and serve as a backup, battery power is not going to power the whole entire sub and magically move the sub quietly through the water, that's not how these things work, that's how nuclear subs work.

My point is, you're not going to be able to move your sub at all on battery power, at some point you will have to turn on those loud ass engines in order to move your sub, which will absolutely alert every modern sub to your location.

[–] [email protected] 6 points 1 year ago* (last edited 1 year ago) (1 children)

Wait so you honestly think they’re going 30,000 km on battery power

Obviously not, as the article I linked to mentions the range is limited in electric mode.

battery power is not going to power the whole entire sub and magically move the sub quietly through the water,

It will, but the range is limited. Electricity and batteries aren't magic. We also use them to move cars.

that’s how nuclear subs work.

You should read the article I linked to above. Current nuclear submarines often aren't perfectly silent. In fact, they can be louder than a modern diesel sub running in battery only mode.

Which is likely why the French, who do have nuclear subs, chose to build a diesel sub anyway while simultaneously also working on quieter nuclear subs.

[–] DigitalTraveler42 1 points 1 year ago (1 children)

From your article:

Diesel Electric Submarines Diesel generator machinery can cause a great deal of noise. Diesel electrics are only quiet when operating in electric mode.

In fact, diesel boats must raise a snorkel to have intake fresh air for combustion when operating the diesel recharging the batteries and is then visible to the world.

u212a todaro class submarine pietro venuti U212A Todaro class submarine Pietro Venuti You cannot run silently with the diesels running and charging the electrics, you can only run silently in the electric-only mode, submerged. And because that’s off batteries, your submerged endurance is limited.

Diesel electric submarines only use diesel mode when travelling on surface, or snorkeling. However, there is the Stirling engine submarine, that can run its two propulsion systems totally submerged.

The works on making nuclear boats quieter

[–] [email protected] 2 points 1 year ago (1 children)

So you agree that diesel submarines can be quieter than nuclear subs when operating in electric mode, although their range is limited.

That's good.

I thought this was turning into one of those reddit level discussions, where people refuse to accept they were wrong, because they'd rather 'win' an argument by misrepresenting what the person they're debating actually said, than have a nuanced discussion

[–] DigitalTraveler42 2 points 1 year ago (1 children)

Bro I just copied and pasted a literal quote from your own article saying otherwise, you are your own Reddit moment rn.

[–] [email protected] 1 points 1 year ago* (last edited 1 year ago)

This is one of the things you quoted:

can only run silently in the electric-only mode, submerged. And because that’s off batteries, your submerged endurance is limited.

Also in the article:

So, unique to nukes, are a bunch of pumps, turbines, and reduction gears, which a diesel boat in battery mode doesn’t have at all.

Ie. a diesel sub is quiet in electric mode, potentially quieter than nuclear subs because in battery mode there aren't turbines or pumps whining away, even though that is for a limited time.

Another example:

Stirling engine is particularly well suited for a submarine because the engine is nearly silent and can use the surrounding sea water as a heat sink to increase efficiency. Submerged endurance is dependent on the amount of liquid oxygen stored on-board and is described as "weeks". The class is characterized by its low acoustic signatures, extreme shock resistance, and a competent combat system. .... The class has many features that enhance stealth, helping it to remain undetected. All shipboard machinery is isolated and mounted on rubber dampeners to reduce vibrations and noises; a hydrodynamic hull design reduces noise, infrared signature, and active sonar response. Its magnetic signature is counteracted by 27 independent electromagnets, short circuiting extremely low frequency (ELF) electrical fields. Various hull coatings reduce active sonar response, and the mast is coated with radar-absorbent material. Combined with the near-silent operation of the Stirling generator and slow-turning propeller to prevent cavitation, the boats are very difficult to detect under water, especially in their normal area of operations, the Baltic Sea

https://en.wikipedia.org/wiki/Gotland-class_submarine

The article goes on to say:

In 2005, HSwMS Gotland managed to snap several pictures of USS Ronald Reagan during a wargaming exercise in the Pacific Ocean, demonstrating that it was in a position to sink the aircraft carrier.[11] The exercise was conducted to evaluate the effectiveness of the US fleet against diesel-electric submarines, which some have noted as severely lacking.

TLDR: an advanced/modern diesel submarine is louder than a nuclear submarine in normal operation. Chugachugachugachuga. Then it goes into battery mode. It goes near silent, quieter than many nuclear submarines which still have turbines, pumps, etc. The diesel sub dissapears like a ghost. Torpedo away, too late.

And that's a relatively old sub. The French sub I mentioned is something like a decade newer, with newer and better batteries.