New Fast-Attack Nuclear Submarines to be Named Arizona and Oklahoma

[Bob DBF]

So the spinning propeller makes no sound?

Obviously depth has input, as does thermo/haloclines, but a spinning prop makes a racket.

Spinning props are for airplanes and skimmers

 

[HalcyonDaze]

So the spinning propeller makes no sound?

Obviously depth has input, as does thermo/haloclines, but a spinning prop makes a racket.

That's added noise, yes, but the typical drawback to most nuke boats is that they aren't totally silent sitting still either as there's still mechanical noise from the reactor pumps. On the Ohio-class subs (and the one-of USS Narwhal) the reactors were designed so that at cruising speeds coolant can be recirculated without using the pumps, which at least cuts that sound source out.

As for the screws, one area where the Soviets managed to catch up in the 1980s was when they managed to import nine-axis milling machines and computer control equipment from Japanese and Norwegian vendors; that allowed them to manufacture quieter propellers for their new sub designs. More modern boats tend to have either shrouded props/pumpjets or other noise reduction features: German Type 212 Sub Has This 'Propeller Boss Vortex Diffuser' To Reduce Its Acoustic Signature

In the fictional tale, the Victor was using the wreck to hide its reactor signature as the "currents whistled through the wreck". Having dove on several dozen individual wrecks they've all been dead silent...

Unlike the Thresher, the crew was alive for a day or two and their government failed them. National Geographic made a lost subs documentary that is about the only thing on the Kursk that is palatable to watch.

The bit from Red Storm Rising goes back to my comment about having to sort out the sub from everything else - you might have a passive sonar array that can literally hear shrimp ****ing; problem is now you're hearing every little noise in the ocean and trying to pick out which one is a sub trying to be sneaky - like trying to listen to one person's footsteps in a noisy bar which may have weird acoustics.

As for the craptacular French "documentary" on the Kursk, oy. For starters, it claims two 688s were trailing the Kursk to listen in on a torpedo test (which it claims were for Chinese representatives onboard); that's plainly ridiculous. There's a reason subs typically work alone; friendly fire and collisions are a real concern when multiple boats are trying to remain stealthy and can't communicate with each other. It goes on to claim that not only did one of the 688s collide with Kursk (for bonus points, I've seen some accounts claiming the exact boat was docked in Scotland on that day) and survive, but as it was retreating the second 688 fired a torpedo (sounds smart, fire a torpedo at an enemy sub that one of your own boats just collided with, I'm sure it'll hit the right one) which punched through Kursk's double hull (uh, modern torpedoes do not work like armor-piercing shells) and caused an explosion in her torpedo compartment. After that highly improbable chain of events, the Russians were somehow charitable enough to completely cover it up by producing a 133-volume report detailing how the sub was blown up by one of its own torpedoes (which supposedly said "documentary" claims were taken out of sevice 10 years earlier; in fact the Type 65-76 was only removed from service after it was identified as the most likely cause of the accident, and a number of years later a Russian admiral was pushing to have them returned to service). For the record, that description comes from collating the summaries I've seen of it; besides not being fluent in French I would need large volumes of wine in order to sit through something that ludicrous.

 

[Akimbo]

There is a lot of machinery besides reactor circ pumps to consider. Generators, motors, refrigeration, environmental cooling, ventilation, flushing the head, food prep, and just working and living. Sure many of these can be shut down when you know you are actively being tracked, but you can't continuously operate that way.

The design challenge is making them as quiet as possible all the time.

 

[HalcyonDaze]

Welp, USS Connecticut made an unannounced stop in San Diego rather than heading straight to Bremerton ... and it looks like the speculation about the bow sonar dome being missing is correct. It'll be interesting to see how that gets addressed.

Damaged Submarine USS Connecticut Appears In San Diego After Secret Journey From Guam (Updated)

The damaged USS Connecticut's covert journey across the Pacific must have been an arduous and complex affair.

www.thedrive.com

 

[Jared0425]

Welp, USS Connecticut made an unannounced stop in San Diego rather than heading straight to Bremerton ... and it looks like the speculation about the bow sonar dome being missing is correct. It'll be interesting to see how that gets addressed.

Damaged Submarine USS Connecticut Appears In San Diego After Secret Journey From Guam (Updated)

The damaged USS Connecticut's covert journey across the Pacific must have been an arduous and complex affair.

www.thedrive.com

I am quite a fan of "The Drive". An excellent open sourced publication that leaves out political nonsense for the most part.

 

[HalcyonDaze]

I am quite a fan of "The Drive". An excellent open sourced publication that leaves out political nonsense for the most part.

I've been following "The War Zone" for years; the articles are generally well informed although sometimes a bit of "armchair expert" opinion kicks in (a frequent one is the old "US should buy this foreign weapons system," e.g. diesel-electric/AIP subs, which doesn't consider that the requirements of the USN may be much different than say, Japan). The comments section is often Russian roulette at times though (literally, as there are more than a few obvious troll farm accounts); I almost joined in this week solely to drop a hammer on one particularly easy target but decided I'd rather not roll in the mud.

 

[HalcyonDaze]

Apparently San Diego was just a quick pit stop: Damaged Submarine USS Connecticut Has Left San Diego On Its Voyage Home (Updated)

Makes sense. Guam to San Diego is a slightly longer transit, but would avoid more weather and make it easier to divert to Pearl Harbor if necessary, followed by a transit hugging the west coast. Just hope they don't run into high winds in the Southern California Bight; one November over a decade ago my advisor and I tried running his 38' sailboat down from Long Beach without really checking the weather. "Ate ****" would be a good description of the experience when the 40-knot Santa Ana winds kicked in.

Also, hopefully they've used up their bad luck on navigational mishaps coming out of the Santa Barbara Channel:

 

[Jared0425]

Apparently San Diego was just a quick pit stop: Damaged Submarine USS Connecticut Has Left San Diego On Its Voyage Home (Updated)

Makes sense. Guam to San Diego is a slightly longer transit, but would avoid more weather and make it easier to divert to Pearl Harbor if necessary, followed by a transit hugging the west coast. Just hope they don't run into high winds in the Southern California Bight; one November over a decade ago my advisor and I tried running his 38' sailboat down from Long Beach without really checking the weather. "Ate ****" would be a good description of the experience when the 40-knot Santa Ana winds kicked in.

Also, hopefully they've used up their bad luck on navigational mishaps coming out of the Santa Barbara Channel:

Now hopefully they can avoid the cameras and media and be able to work on the boat without our adversaries dissecting the pictures.

 

[Jared0425]

 

[HalcyonDaze]

Connecticut appears to have made it back to Kitsap on the 19th; it appears that the 2022 National Defense Authorization Act includes a $10 million line item for a "spare Seawolf-class bow dome" and another $40 million line item for "USS Connecticut emergent repairs." Wonder if that will cover everything or just the initial stuff; I would think that after having six weeks to look the boat over in Guam they have an idea on what the total amount of repairs needed are. She was actually supposed to start a 2-year maintenance period last year which was put off; apparently one of the problems with getting her in for repairs will be the drydock at Bremerton is currently occupied by the decommissioned 688-class boats Olympia (SSN-717) and Louisville (SSN-724) which are undergoing inactivation.

Congress Has Already Allocated Tens Of Millions For USS Connecticut Repairs

Congress has approved $50 million in total to help fix the USS Connecticut, but the repair bill could grow to be significantly larger.

www.thedrive.com