Since the other sub thread got locked, i'd just like to say we have the best diesel subs in the world these days :D

[radioouman]

Diesel?? Why not nuclear?

 

[techs]

Actually the AIPS subs are the best combination of stealth and endurance.
Air Independent Propulsion System.

 

[LeadMagnet]

Diesel is quieter (runs on batteries under water), Diesel is cheaper to build, staff, and maintain

but nukes can go for years submerged before refueling (humans are the weakest link)

 

[marvdmartian]

Originally posted by: Specop 007

Originally posted by: preslove

Originally posted by: dug777
Anyway, to drag the thread back on topic, we do have the best diesel subs going these days, and there is a view in the US military establishment that they erred in letting their diesel program die, diesel subs bring a lot to the ball game

Could someone explain the advantages of diesel propulsion? Is it that it allows for a smaller/faster sub?

Quieter systems. You can turn off EVERYTHING and just be a hole in the ocean. Nuke subs require a minimum of machinery to be running, namely the coolant pumps.

Each system has its positives and negatives. Nukes can leave harbor, go underwater and stay there for 3 months, 6 months, however long you want. They can travel anywhere on the globe until the crew runs out of food and starves.

Deisel electrics require air to run the diesels to charge the batteries, which means they have to occasionally come up for air. They need diesel fuel to keep the engines running as well, which means your range is limited by your fuel supply. But in electric mode, its the quietest thing in the water aside from a fish.

What you say is true, to a point. Comparitively speaking, a diesel boat under electric propulsion is quieter than a Los Angeles nuke, because of the propulsion machinery noise the LA class makes. That's a big part of the reason why the Ohio class boomers are designed to go up to 10% reactor power (basically, high enough to maintain steerage in the water) without reactor coolant pumps. Now would you like to compare quietness?? Cuz the US navy pretty much wrote the book on it, and I've heard it said that if the LA class attack boats are a shadow in the water, then the Ohio class boomers are a black hole with their coolant pumps turned off.

Now consider that the Seawolf class boats were made with the technology that the US Navy perfected with the LA and Ohio class boats. It just plain sucks that they've chopped the numbers so drastically on how many of those boats will be made, but I'd hate to go up against a Seawolf with anything......they're the shadow made by the black hole, ya know??

Oh yeah, and diesels have the weakest point of all.......when they have to surface to snorkel depth, in order to start up that noisy diesel engine, to recharge their batteries. Once you've done that, if there's a SOSUS network nearby (not to mention one of those "noisy" LA class boats), you're dead meat......even after you've shut down your diesel, cuz finding someone's tough, but keeping them in "sight" after they let you find them is a lot easier. At least, that's what the senior chief sonarman I worked for told me once.

 

[iamaelephant]

Wow this thread is a real pissing contest huh?

 

[AmphibSailor]

Ohio class boomers are designed to go up to 10% reactor power

You're seriously underestimating the power of natural circulation designed into the S8G reactor. I'm sure the numbers went up or were at least equal with their replacement, the S6W, too.

Qualified/Requalified SS on Pulaski*, Bancroft* and Tunny*.




*Neither diesel, Ohio, nor LA class but nonetheless SS.

 

[smack Down]

Originally posted by: dug777

Originally posted by: Specop 007

Originally posted by: dug777

Originally posted by: Acanthus
But uhh, our best subs arent diesel

Thats like saying we have the best go kart when it comes to racing.

Well, they appear to have bested your nukular subs and a carrier in combat situations, so...i can't really see your point actually

EDIT: not to mention that i don't think you actually have any modern diesel combat subs...

And considering wargames usually hamstring someone in one way or another it means very little. Let them play a "real" wargames scenario. No tied hands, no limits, no little playing field. THEN lets see what happens.

How exactly would you play a 'real' scenario? Let them shoot each other?

You are making baseless assumptions that 'you' were hamstrung because there is no possible way in your mind you could not be the best at everything :laugh:

If we weren't hamstrung then down under would be a parking lot.

 

[Whitecloak]

australia has a navy?

 

[dug777]

Originally posted by: Whitecloak
australia has a navy?

india has a cricket team?

 

[Whitecloak]

Originally posted by: dug777

Originally posted by: Whitecloak
australia has a navy?

india has a cricket team?

:laugh:

 

[dug777]

Originally posted by: Whitecloak

Originally posted by: dug777

Originally posted by: Whitecloak
australia has a navy?

india has a cricket team?

:laugh:

:beer: mate

 

[Calin]

Originally posted by: Specop 007

Originally posted by: preslove

Originally posted by: dug777
Anyway, to drag the thread back on topic, we do have the best diesel subs going these days, and there is a view in the US military establishment that they erred in letting their diesel program die, diesel subs bring a lot to the ball game

Could someone explain the advantages of diesel propulsion? Is it that it allows for a smaller/faster sub?

Quieter systems. You can turn off EVERYTHING and just be a hole in the ocean. Nuke subs require a minimum of machinery to be running, namely the coolant pumps.

Each system has its positives and negatives. Nukes can leave harbor, go underwater and stay there for 3 months, 6 months, however long you want. They can travel anywhere on the globe until the crew runs out of food and starves.

Deisel electrics require air to run the diesels to charge the batteries, which means they have to occasionally come up for air. They need diesel fuel to keep the engines running as well, which means your range is limited by your fuel supply. But in electric mode, its the quietest thing in the water aside from a fish.

There might be "low power" settings on a nuclear reactor so it runs without pumps - but the boiling of water still makes some noise (you can't completely shut down the nuclear power plant). Also, a nuclear sub has batteries (as backups) - but these will only allow it some hours of movement (unlike days for a diesel)

 

[Slikkster]

You can bet that Putin wishes Tom Clancy's caterpillar drive boomer from Red October really came into existence. Of course, Jonesy would have sniffed out at some point, Sea-Man Beaumont.

 

[Acanthus]

Originally posted by: Calin

Originally posted by: Specop 007

Originally posted by: preslove

Originally posted by: dug777
Anyway, to drag the thread back on topic, we do have the best diesel subs going these days, and there is a view in the US military establishment that they erred in letting their diesel program die, diesel subs bring a lot to the ball game

Could someone explain the advantages of diesel propulsion? Is it that it allows for a smaller/faster sub?

Quieter systems. You can turn off EVERYTHING and just be a hole in the ocean. Nuke subs require a minimum of machinery to be running, namely the coolant pumps.

Each system has its positives and negatives. Nukes can leave harbor, go underwater and stay there for 3 months, 6 months, however long you want. They can travel anywhere on the globe until the crew runs out of food and starves.

Deisel electrics require air to run the diesels to charge the batteries, which means they have to occasionally come up for air. They need diesel fuel to keep the engines running as well, which means your range is limited by your fuel supply. But in electric mode, its the quietest thing in the water aside from a fish.

There might be "low power" settings on a nuclear reactor so it runs without pumps - but the boiling of water still makes some noise (you can't completely shut down the nuclear power plant). Also, a nuclear sub has batteries (as backups) - but these will only allow it some hours of movement (unlike days for a diesel)

The thing i saw on TV about the swedish powerplant for the subs measured the battery life in hours, not days.

 

[EvilYoda]

Kind of related tidbit: my friend works for the Navy on noise and vibration and has to take a week-long "trip" on a sub in a few weeks, but he's done it before...gets flown down to San Diego he says, since they don't have a permanent N&V team down there or something.

I wish I knew more about what he does, sounded cool.

 

[AndrewR]

It's probably a toss up between the Swedes and the Germans for the best diesel-electric boat. Remember, the Germans wrote the book on them.

You know that massively powerful sonar that kills whales and everything else within several miles when it's used by the USN? The eco-terrorists can thank diesel-electric boats for that. Now, beach some whales and find those subs!

 

[miniMUNCH]

Well...what not to believe. I mean, it was on wikipedia, quoted from a news paper who quoted a skipper who's probably looking to justify a sub program and maybe get a promotion. Come on... that is Colbert rock-solid, baby.

 

[miniMUNCH]

Dug777, dude... the wiki info about your sub dustin our sub twice comes from a five sentence aussie article. I'm not implying that the article is lying...just that it does not contain all the facts of the excercises.

A number of points:

- in a couple of weeks of war games...they would have run way more than two or three exercises...more like 10-20. What happened in all the other situations?
- The LA class sub is 25+ year old technology. Virginia class subs are ridiculously quiet and SONAR / other sensory equipment is state of the art (Read - better than anything else out there.
- as others have pointed out... the LA class subs probably hamstrung themselves. Just by virtue of so much intel on LA class subs being "freely" available the LA class subs were at a serious disadvantage.

All that being said... those aussie subs are probably really, really sneaky.

Edit: and that exercise was 3 years ago.

 

[Calin]

Originally posted by: Acanthus

The thing i saw on TV about the swedish powerplant for the subs measured the battery life in hours, not days.

The Tambor class submarines (US, built in 1939) had a submerged endurance of 48 hours at 2 knots
Tench class (last WW2 american design) had the same endurance (two days at slow speed)

The Kilo class has 400 miles at 3 knots endurance - this means 133 hours submerged, or 5 days.
Diesel subs are made to wait in an area, not to patrol it - they are noisy when their diesel engines run, and a day of going at 6-7 knots will probably drain their batteries.

 

[AmphibSailor]

There might be "low power" settings on a nuclear reactor so it runs without pumps - but the boiling of water still makes some noise (you can't completely shut down the nuclear power plant).

I guess it all depends on what you mean by "low power." I really don't think you have any idea. These reactor cores are designed for and are capable of operating at a significant fraction of full power without the use of their main coolant pumps. They are quiet reactor plants.

And YES you are right...boiling water makes noise. However, these systems are closed loop(s) with steam bubbles theoretically only in the pressurizer(s). More noise would be generated by someone banging a stall door in the head (we didn't use doors) which creates transients that are much easier to pick up through background noise.

As an aside, an S8G produces about 60,000 shaft horsepower (ballpark) and the S6W about 50,000 on Ohio class and Seawolf class submarines, respectively. So at 745.7 watts per hp...that means between 37 and 44.7 megawatts.

Anyhow...just thought I'd pass some trivia on...I really didn't mean to flame...just that subs were an important part of my early career.

 

[dxkj]

Originally posted by: Specop 007

Originally posted by: preslove

Originally posted by: dug777
Anyway, to drag the thread back on topic, we do have the best diesel subs going these days, and there is a view in the US military establishment that they erred in letting their diesel program die, diesel subs bring a lot to the ball game

Could someone explain the advantages of diesel propulsion? Is it that it allows for a smaller/faster sub?

Quieter systems. You can turn off EVERYTHING and just be a hole in the ocean. Nuke subs require a minimum of machinery to be running, namely the coolant pumps.

Each system has its positives and negatives. Nukes can leave harbor, go underwater and stay there for 3 months, 6 months, however long you want. They can travel anywhere on the globe until the crew runs out of food and starves.

Deisel electrics require air to run the diesels to charge the batteries, which means they have to occasionally come up for air. They need diesel fuel to keep the engines running as well, which means your range is limited by your fuel supply. But in electric mode, its the quietest thing in the water aside from a fish.

So why dont we design some nuclear/electrics? Or is it that even if we charge up enough juice, we can never shut the nuke stuff down (not a nuke person)

 

[K1052]

When fitted out with US control and weapons systems.

The Germans make some really nice stuff too.

 

[nCred]

http://www.naval-technology.com/projects/gotland/

"PROPULSION SYSTEMS

The submarine is equipped with two MTU diesel engines and two Kockums V4-275R Stirling Air Independent Propulsion (AIP) units.

The Stirling engines are mounted in elastic, soundproof modules and each provide up to 75kW. The submarine has the capacity for two weeks of air independent propulsion at a speed of 5kt without snorting.

The AIP uses liquid oxygen and diesel fuel in a controlled inert (helium) environment. The AIP liquid oxygen tanks are located on the deck below the engines. The propulsion system provides a speed of 11kt surfaced and 20kt dived. "

 

[Exterous]

Originally posted by: dxkj

Originally posted by: Specop 007

Originally posted by: preslove

Originally posted by: dug777
Anyway, to drag the thread back on topic, we do have the best diesel subs going these days, and there is a view in the US military establishment that they erred in letting their diesel program die, diesel subs bring a lot to the ball game

Could someone explain the advantages of diesel propulsion? Is it that it allows for a smaller/faster sub?

Quieter systems. You can turn off EVERYTHING and just be a hole in the ocean. Nuke subs require a minimum of machinery to be running, namely the coolant pumps.

Each system has its positives and negatives. Nukes can leave harbor, go underwater and stay there for 3 months, 6 months, however long you want. They can travel anywhere on the globe until the crew runs out of food and starves.

Deisel electrics require air to run the diesels to charge the batteries, which means they have to occasionally come up for air. They need diesel fuel to keep the engines running as well, which means your range is limited by your fuel supply. But in electric mode, its the quietest thing in the water aside from a fish.

So why dont we design some nuclear/electrics? Or is it that even if we charge up enough juice, we can never shut the nuke stuff down (not a nuke person)

IIRC you can shut down the reactor but you can't really start it up in a timely manner. (I don't remember if this requires a drydock or not). Its not the best tacticle option more of an emergency safety procedure to keep you from glowing in the dark.

 

[Gibsons]

Originally posted by: Exterous

Originally posted by: dxkj

Originally posted by: Specop 007

Originally posted by: preslove

Originally posted by: dug777
Anyway, to drag the thread back on topic, we do have the best diesel subs going these days, and there is a view in the US military establishment that they erred in letting their diesel program die, diesel subs bring a lot to the ball game

Could someone explain the advantages of diesel propulsion? Is it that it allows for a smaller/faster sub?

Quieter systems. You can turn off EVERYTHING and just be a hole in the ocean. Nuke subs require a minimum of machinery to be running, namely the coolant pumps.

Each system has its positives and negatives. Nukes can leave harbor, go underwater and stay there for 3 months, 6 months, however long you want. They can travel anywhere on the globe until the crew runs out of food and starves.

Deisel electrics require air to run the diesels to charge the batteries, which means they have to occasionally come up for air. They need diesel fuel to keep the engines running as well, which means your range is limited by your fuel supply. But in electric mode, its the quietest thing in the water aside from a fish.

So why dont we design some nuclear/electrics? Or is it that even if we charge up enough juice, we can never shut the nuke stuff down (not a nuke person)

IIRC you can shut down the reactor but you can't really start it up in a timely manner. (I don't remember if this requires a drydock or not). Its not the best tacticle option more of an emergency safety procedure to keep you from glowing in the dark.

I think that's basically right. Shutting down a reactor can be done quickly, but starting them back up isn't a trivial process and takes some time. There's also the question of space, which is very precious on a sub.

Hopefully AmphibSailor can fill in some details and/or correct us.