Chinese supersonic submarine ...?

[InterCity]

This morning, I found this while randomly browsing the abyss known as the Internet and found a variation of this in my language on a quite trustworthy news server:

http://www.telegraph.co.uk/luxury/travel/44585/the-next-big-thing-launch-of-the-supersonic-submarine.html

Out of sheer curiosity, I clicked on the link and it sounded to me like sheer propaganda, or something as likely as, for instance, pigs flying - at least in near future for several reasons:

1. Water resistance - it's quite hard to reach supersonic in air, but doing it in water requires helluva lot more of thrust - especially when we're talking about a submarine. They said that they can spread exhaust fumes in front of the sub but still...
   
2. Steering - the only thing that has done this and worked so far, was the soviet Shkval torpedo - and that was about as controllable as a bucket of rusty nails flying at 200 kts.
   
3. Fuel - You can't pull off stunts like this with conventional water jet or a standard propeller. This requires heavy-duty rocket engine (especially underwater), and these are very thirsty. A sub this fast wouldn't have enough fuel to do anything meaningful.
   

Am I right that it's not going to happen (at least in near future) or did I miss something?

[Darnok]

here is more about "how" it is possible

http://www.smh.com.au/technology/technology-news/chinese-reportedly-working-on-superfast-submarine-that-would-fly-in-an-air-bubble-20140826-108tfw.html

[Rokker]

I think you would be much better off on the surface for such a high speed vehicle.

[YNM]

So... Somebody is going to proof this, no ?

[78stonewobble]

Yeah, I was thinking about the fuel/range as well... Does seem to make more sense for torpedoes.

[xenomorph555]

I remember seeing this a while ago, the technology is there but no it won't be built. Their more likely to do supersonic planes or trains.

[Darnok]

I remember seeing this a while ago, the technology is there but no it won't be built. Their more likely to do supersonic planes or trains.

I doubt it that military would use trains to reach targets over ocean

[K^2]

Soviets have built a torpedo that does much the same thing. So the technology for it is actually proven. Building it on larger scale and with any sort of significant range, however, is a colossal challenge.

VA-111 Shkval

[WestAir]

Soviets have built a torpedo that does much the same thing. So the technology for it is actually proven. Building it on larger scale and with any sort of significant range, however, is a colossal challenge.

VA-111 Shkval

An entire submarine, though? Given the direction modern naval combat is progressing, I wonder if the endeavor is even worth the effort?

[DAL59]

This is very dubious and has been debunked by CNN.  You see, they were not just claiming supersonic speeds, but orbital speeds! 6100 miles per hour!  

http://time.com/3182422/chinese-supersonic-submarine/

[DDE]

20 hours ago, DAL59 said:

This is very dubious and has been debunked by CNN.  You see, they were not just claiming supersonic speeds, but orbital speeds! 6100 miles per hour!  

http://time.com/3182422/chinese-supersonic-submarine/

Adding a few zeros FOR THE MOTHERLAND.

On ‎06‎.‎10‎.‎2015 at 12:26 AM, K^2 said:

Soviets have built a torpedo that does much the same thing. So the technology for it is actually proven. Building it on larger scale and with any sort of significant range, however, is a colossal challenge.

VA-111 Shkval

The Shkval lacks the insane speeds claimed, because it still touches water. Which is why I smell a rat: you'd need an insane level of gas production to maintain the bubble without having to push at the water ahead. You'd need to slice in an exert an insane force.

[Scotius]

And, aside from ridiculous power requirements, such submarine would be literally blind and deaf while moving. And it would broadcast its position, speed and course to EVERYONE. Very, very LOUDLY. That's not a thing submarines are built for

[kerbiloid]

Spoiler

Super Sonic Submarine

 

[DAL59]

1 hour ago, Scotius said:

And, aside from ridiculous power requirements, such submarine would be literally blind and deaf while moving. And it would broadcast its position, speed and course to EVERYONE. Very, very LOUDLY. That's not a thing submarines are built for

For orbital speed, it would be easier to have a rocket

[Niccolo]

On 1/10/2018 at 9:51 AM, DAL59 said:

This is very dubious and has been debunked by CNN.  You see, they were not just claiming supersonic speeds, but orbital speeds! 6100 miles per hour!  

http://time.com/3182422/chinese-supersonic-submarine/

Not quite - orbital velocity is well above 6000 mph. A circular orbit in LEO requires a velocity of 7-8 km/s, or 25-30,000 km/h (~ 15-19,000 mph).

It's still seriously damn fast though. I'm not entirely sure supercavitation would even be possible at such a speed. The sub would probably outpace any gas bubble that tries to form and what follows would be exactly what happens when a rocket plows into the ground, since at that speed there's not much difference between hitting water and hitting rock.

[Shpaget]

Evev with some conservative cross section of 75 m^2 (based on 10 m diameter) at 6000 mph (3000 m/s) it would need to push 225 000 cubic meters of water out of its way each second.

No.

[wumpus]

On 10/5/2015 at 5:26 PM, K^2 said:

Soviets have built a torpedo that does much the same thing. So the technology for it is actually proven. Building it on larger scale and with any sort of significant range, however, is a colossal challenge.

VA-111 Shkval

There is at least some point to having an extremely fast torpedo: to make it unavoidable.  The only reason to build a superfast submarine is if it were easier than building an equally fast, equally large surface ship or airplane.  The thing would stick out like a sore thumb (exactly the opposite of why most submarines are built/used) and still operate in a hazardous environment.  Presumably the "air bubble" might help for defense: like horseshoes and hand grenades, close counts with depth charges.  You might need a difficult shot with a VA-111 (or faster) torpedo to kill such a beast, but I doubt that is sufficient reason to build such a thing.  You're essentially betting that a carrier (or ground, I expect Chinese doctrine will be based on overwhelming numerical advantage on the ground for quite some time) launched aircraft can't kill an underwater craft with a well known position.  That is a bet I wouldn't take (at least not on the sub's side).

An ultra-fast sub is as dumb as an ultra-large sub.  The moment you give away its position it is useless.

I'd also expect that the Shkval is close to the limit for submerged speed, any claims to "supersonic" are absurd as noted above.

[kerbiloid]

Spoiler

Orion developers missed so great chance: a supersonic submarine with nuclear pulse propulsion. Crossing an ocean in several jumps.

According to wiki, Shkval velocity is 370 km/h. This is four times less than a sound speed even in air.

Edited January 11, 2018 by kerbiloid

[peadar1987]

On 11/01/2018 at 2:50 PM, wumpus said:

There is at least some point to having an extremely fast torpedo: to make it unavoidable.  The only reason to build a superfast submarine is if it were easier than building an equally fast, equally large surface ship or airplane.  The thing would stick out like a sore thumb (exactly the opposite of why most submarines are built/used) and still operate in a hazardous environment.  Presumably the "air bubble" might help for defense: like horseshoes and hand grenades, close counts with depth charges.  You might need a difficult shot with a VA-111 (or faster) torpedo to kill such a beast, but I doubt that is sufficient reason to build such a thing.  You're essentially betting that a carrier (or ground, I expect Chinese doctrine will be based on overwhelming numerical advantage on the ground for quite some time) launched aircraft can't kill an underwater craft with a well known position.  That is a bet I wouldn't take (at least not on the sub's side).

An ultra-fast sub is as dumb as an ultra-large sub.  The moment you give away its position it is useless.

I'd also expect that the Shkval is close to the limit for submerged speed, any claims to "supersonic" are absurd as noted above.

This. The only reason submarines are a thing is being difficult to detect. Once you do something like this you have defeated pretty much the entire point of the vessel.

[Hannu2]

I would think, that ability to run some distance at ridiculous speed would be practical if there were problems in naval fight. Especially if it would be impossible to follow the submarine with plane. If it got hundred kilometers of distance it would be able to continue slowly and silently to unknown direction and disappear before the enemy would get some units at latest known position. But achieving that kind of speeds in real world is not credible at all, in my opinion.

[kerbiloid]

16 minutes ago, Hannu2 said:

it would be impossible to follow the submarine with plane

It unlikely would be required. Just drop an anker chain on its way, it will crash her forehead herself.

[p1t1o]

*reads thread title*

*laughs for a century*

No. A most intense No. Warranting no discussion.

This is a gullible-people detector. Makes about as much sense as a dirigible fighter jet. Actually since a dirigible fighter jet would resemble a SAM-site in the sky and as such still have some tactical utility, the dirigible fighter jet is a far superior idea.

If you are thinking "Im a scientist/scientifically minded, I should give this idea a chance and look into it"

Save yourself some time, give something else a chance instead.

 

If you *must* have a reason, just calculate the mass of water that would need to move out of the way of a submarine of any size moving at 330m/s (Im ASSUMING [for sanity's sake] they werent talking about the speed of sound in water, ~1500m/s) and work out the kinetic energy expenditure required, then google the power output of nuclear reactors.)

 

Ok fine I'll do a back-of-the-napkin.

Lets assume a diameter of 10m

So thats [Pi*5^2]*330 cubic metres of water accelerated to [near enough, dependant on submarine geometry, amongst other things] 330m/s, per second.

Thats 25 thousand tons of water, accelerated to [near enough] 330m/s, per second. 

Do I need to continue? This calculation ignores many things, including drag and assumes 100% efficiency. Reality will be much, much worse.

 

You wanna calculate the dynamic pressure on the nose of the submarine and see if any known materials can withstand it? Because the fastest known submarine topped out at around 45kts and surfaced with severe damage, and it was also a pretty deep-diving (ie: solidly-built) vessel too. https://en.wikipedia.org/wiki/Soviet_submarine_K-222

 

This is not a case of "one day we might have the technology to build this", this is a case of "an in-atmosphere aircraft that travels at 0.9c is a similarly good idea".

Well, more accurately, its a case of "How do I get more clicks on my site?"

 

 

 

[kerbiloid]

It's a submersible satellite in underwater orbit.

[DAL59]

3 hours ago, p1t1o said:

If you *must* have a reason, just calculate the mass of water that would need to move out of the way of a submarine of any size moving at 330m/s (Im ASSUMING [for sanity's sake] they werent talking about the speed of sound in water, ~1500m/s) and work out the kinetic energy expenditure required, then google the power output of nuclear reactors.)

Actually, its even worse than that.  They said it would move 6 kilometers per second.  Underwater.   

There's something called a rocket you could use as well, and would be equally stealthy(that is to say, not at all.)