PLAN Type 035/039/091/092 Submarine Thread

[Ambivalent]

Re: PLAN submarines Thread II

I'm not so sure about the drainage hole problem. Other, modern western subs have them too, its just that they positioned differently so they're less visible on pictures. Japanese Oyashio subs have them positioned lower, so they're mostly underwater and not noticable when the sub is not in dry dock. Newest british attack subs, astute class, also have them alongside whole body - here they're even somewhat high up and could be noticed even when sub is in the water.

Limber holes as they are properly called create noise through what is known as Helmholtz Resonance. Blow across the top of a soda bottle and you hear a noise. The same property of fluids causes water flowing across an opening in a submarine hull to make noise. This is why you do not see free flooding spaces and their associated limber holes on US attack subs.

 

[Skywatcher]

Re: PLAN submarines Thread II

Limber holes as they are properly called create noise through what is known as Helmholtz Resonance. Blow across the top of a soda bottle and you hear a noise. The same property of fluids causes water flowing across an opening in a submarine hull to make noise. This is why you do not see free flooding spaces and their associated limber holes on US attack subs.

On the other hand, isn't that problem resolved if you just close off the limber holes?

 

[montyp165]

Re: PLAN submarines Thread II

Limber holes as they are properly called create noise through what is known as Helmholtz Resonance. Blow across the top of a soda bottle and you hear a noise. The same property of fluids causes water flowing across an opening in a submarine hull to make noise. This is why you do not see free flooding spaces and their associated limber holes on US attack subs.

The Russians have already managed that well enough to match USN subs in quietness, so that in itself is not a big issue.

 

[Pointblank]

Re: PLAN submarines Thread II

The Russians have already managed that well enough to match USN subs in quietness, so that in itself is not a big issue.

Not exactly; they only matched the performance of a early LA boat, while the later LA boats, then the Ohio, Seawolf, and Virgina's are even more quiet. The Russians are still behind us by a good decade.

 

[Ambivalent]

Re: PLAN submarines Thread II

On the other hand, isn't that problem resolved if you just close off the limber holes?

Which is why American boats don't have them. US sub designers put the ballast tanks at either end of the boat, not along the flanks as most other navies do, eliminating free flooding spaces and the need for limber holes. Since the boats don't need to submerge from the surface quickly like diesel boats often do, but stay deeply submerged, there is only a single vent per ballast tank.

 

[Skywatcher]

Re: PLAN submarines Thread II

Which is why American boats don't have them. US sub designers put the ballast tanks at either end of the boat, not along the flanks as most other navies do, eliminating free flooding spaces and the need for limber holes. Since the boats don't need to submerge from the surface quickly like diesel boats often do, but stay deeply submerged, there is only a single vent per ballast tank.

You can't go down too deeply in Chinese coastal waters.

 

[Ambivalent]

Re: PLAN submarines Thread II

Not exactly; they only matched the performance of a early LA boat, while the later LA boats, then the Ohio, Seawolf, and Virgina's are even more quiet. The Russians are still behind us by a good decade.

A Virginia class boat at 20 kts is quieter than an LA class boat tied to the pier with it's reactor lit off.

 

[A.Man]

Re: PLAN submarines Thread II

A New Photo Of 094 Sub In A Chinese Website.

 

[snake65]

Re: PLAN submarines Thread II

A New Photo Of 094 Sub In A Chinese Website.

I don't see limber holes on the hump. Are they just in the shadow or what we have seen before has been a photoshop?

 

[Infra_Man99]

Re: PLAN submarines Thread II

A Virginia class boat at 20 kts is quieter than an LA class boat tied to the pier with it's reactor lit off.

I don't doubt the superior stealth of a Virginia class over an LA class, but I don't think this is a fair comparison. I'm not an expert on this stuff, so correct me if I'm wrong.

Isn't it true that a submarine parked next to a regular pier or parked in VERY shallow waters is easier to detect than the same submarine in deep waters? Isn't it true that any ship is easier to detect when it is parked in a regular pier/very shallow waters than when it is out in the ocean?