NationStates Jolt Archive

For all the defense-tech/submarine afficionados out there...a question.

Would it be feasible to incoroprate a fuel-cell propulsion system, such as that found in the German Type 212, with a large cruise missile platform, such as the US's converted Ohio SSGNs?

From what I understand, the actual power of the fuel-cells themselves is fairly low, and I'm wondering if putting them in such a large platform is possible while still maintaining a respectable speed.

A nearly silent sub capable of launching over 150 cruise missiles...but can it be done?

For all the defense-tech/submarine afficionados out there...a question.

Would it be feasible to incoroprate a fuel-cell propulsion system, such as that found in the German Type 212, with a large cruise missile platform, such as the US's converted Ohio SSGNs?

From what I understand, the actual power of the fuel-cells themselves is fairly low, and I'm wondering if putting them in such a large platform is possible while still maintaining a respectable speed.

A nearly silent sub capable of launching over 150 cruise missiles...but can it be done?
The problem with the solution is the need for hydrogen or other catalyst (hydrogen being the most common)

With as large as the Ohio Class are the advantage of a strategic missile platform as they currently exist is the crazy amount of time they can be deployed as a deterrent

Tying them down to some place to provide fuel will neutralize many of the long deployment missile platforms advantages, regardless of the ability to run them like that , having to bring them in for refueling will just add to the ability to track them.

But that's with a SSBN...which plays a far different role from a SSGN, which is more of a tactical role against enemy fleets or ground positions. It doesn't necessarly need to remain on standing patrol for long periods of time.

And I'm also not necessarily applying this to the US armed forces...I'm just wondering if it would be possible, not necessarily practical.

But that's with a SSBN...which plays a far different role from a SSGN, which is more of a tactical role against enemy fleets or ground positions. It doesn't necessarly need to remain on standing patrol for long periods of time.

And I'm also not necessarily applying this to the US armed forces...I'm just wondering if it would be possible, not necessarily practical.
From what I have seen of fuel cell technology it would be possible but more bulky then the current systems. … would the sound difference be that much of an advantage?

Depends on how you use it...

...if most of your surface fleet is off somewhere, a few of those along your coast would be a nice safety blanket from enemy naval action.

If it's too slow a platform though, it becomes extra vulnerable after launch due to it's inability to vanish at a decent rate. Would the weight to power ratio give it a decent enough speed versus its increased bulk?

Depends on how you use it...

...if most of your surface fleet is off somewhere, a few of those along your coast would be a nice safety blanket from enemy naval action.
But you have to remember their reduced cruze time and extra propulsion bulk.. I just dont see it as efficent

If it's too slow a platform though, it becomes extra vulnerable after launch due to it's inability to vanish at a decent rate. Would the weight to power ratio give it a decent enough speed versus its increased bulk?
Agreed you are going to be sacrificing possibly range, speed, bulk and space for sound performance

Nuke boats are already supposed to be pretty damned quite, aren't they? As I understand it, a large portion of th enoise from a sub comes from the props. Quieter props would probably be more useful than a new, slower, bulkier power sytem.

Nuke boats ARE quiet, but nuclear reactors simply create noise that can't be eliminated...it can be reduced significantly, but not eliminated.

Reduced range is already a given, but would a fuel-cell propulsion system for this large of a platform necessarily be larger or bulkier than a nuclear reactor? Espcecially if a decent top speed is desired?

According to this (http://www.fuelcelltoday.com/FuelCellToday/IndustryInformation/IndustryInformationExternal/IndustryInformationDisplayArticle/0,1588,471,00.html), every one of the upgraded modules used in the Type 214 produces 120kW. The exact size of them would be good to know, I'll have a look.

As you can see on this picture (http://www.naval-technology.com/projects/type_212/images/type212_3.jpg), I don't think they have to be particularly bulky (the 212 is only 56m long). But they can't be used as the only system. For normal cruising and the like the German ones use a diesel.

I think that compared to a nuclear-powered sub the advantage wouldn't so much lie with noise, but perhaps moreso with heat. Nuclear engines tend to run pretty hot, which might be easier to detect than a fuel cell which produces virtually no heat at all.

EDIT:
I couldn't find info on their exact dimensions, but here is what I found anyways:
http://www.industry.siemens.com/broschueren/pdf/Marine/Sinavy/en/SINAVY_PEM_Fuel_Cell.pdf
http://www.industry.siemens.com/marine/en/solution/pma_detail.htm?id=853&family=SINAVY&PIdent=&SIdent=

Fuel cells have the advantage of being silent – but the noise produced from the reactor is minimal. Sound is not a major issue in the hydrogen fuel cell vs nuclear reactor debate as it is such an insignificant contribution – the gears and props produce the majority of the noise in the propulsion system – not the power generation itself.

Range is likewise not an issue because the subs can take their hydrogen straight from the water around them. A couple years ago the navy wanted to look into using a hydrogen fuel cell system with surface vessels. They were pushing all sorts of developments toward the goal of having even small surface vessels able to stay deployed indefinitely, and a fuel cell refueled from water around it was a way to accomplish this.

Basically what was developed was a series of panels to be placed along the hull which would absorb some hydrogen from the water. It would supply enough hydrogen to power the ship without difficulty, but was prohibitively expensive to build. While it did not make sense for surface vessels, it might for submarines.

So if you do not have to worry about fuel, and the noise difference would not be all that important (you still have the same propulsion system just with a different power source), the only real concern will be the bulk of the system. I have no idea just how large a power system would have to be in comparison to a reactor, but I suspect (just an unsubstantiated shot in the dark) that a reactor can provide significantly more power per cubic foot than using an array of fuel cells.

Is there any shipyard in the U.S with the experience and expertise to maintain this type of fuel cell propulsion system? Probably hard to find. The USN is never going to live it down having a Ohio being stripped down in a foreign shipyard - a number of quietness features are still considered secrets.

Besides, where will the funding come from?

Nuke boats ARE quiet, but nuclear reactors simply create noise that can't be eliminated...it can be reduced significantly, but not eliminated.

Yes you can. It's called shutting off the reactor. Or SCRAMing it :p


Reduced range is already a given, but would a fuel-cell propulsion system for this large of a platform necessarily be larger or bulkier than a nuclear reactor? Espcecially if a decent top speed is desired?

Well, fuel cells aren't exactly the most efficient power sources aren't they? Quiet yes, but not that energetic as a nuclear reaction. To get comparable amounts of power, it's likely that you'd either have to bulk up the submarine or sacrifice some compartments.

Is there any shipyard in the U.S with the experience and expertise to maintain this type of fuel cell propulsion system? Probably hard to find. The USN is never going to live it down having a Ohio being stripped down in a foreign shipyard - a number of quietness features are still considered secrets.

Besides, where will the funding come from?

As I stated before, this is not necessarily a US-oriented question...simply a hypothetical using the largest tactical undersea platform currently in use as an example.

And as far as I know, only the Germans currently have the facilities to construct fuel-cell submarines...they're making them for the Italians, the Greeks and the South Koreans as well as themselves.

Yes you can. It's called shutting off the reactor. Or SCRAMing it :p



Well, fuel cells aren't exactly the most efficient power sources aren't they? Quiet yes, but not that energetic as a nuclear reaction. To get comparable amounts of power, it's likely that you'd either have to bulk up the submarine or sacrifice some compartments.


I seem to recall that Ivan had something like 40% of his Typhoons filled up with batteries. Ivan had a preference for dual drives when it came to boomers.

Yes you can. It's called shutting off the reactor. Or SCRAMing it :p
LOL. Scramming a reactor is most definitely not quiet.

EDIT (Semantics): And U.S. Navy reactors aren't "shut off," they're "shut down." ;)

LOL. Scramming a reactor is most definitely not quiet.

Don't bluff. It's plenty quiet after it's scrammed. :p

I seem to recall that Ivan had something like 40% of his Typhoons filled up with batteries. Ivan had a preference for dual drives when it came to boomers.

If I remember the construction schematics correctly, those batteries were right next to the hull. Makes it extra durable I suppose. But not sure how much more durable since the days of depth charges were long since gone when they made those boomers.

And batteries =/= fuel cells.

Don't bluff. It's plenty quiet after it's scrammed. :p



If I remember the construction schematics correctly, those batteries were right next to the hull. Makes it extra durable I suppose. But not sure how much more durable since the days of depth charges were long since gone when they made those boomers.

And batteries =/= fuel cells.


I know they aren't the same - but I keep thinking that making the boats bigger to give 'em better legs makes good sense.
Another era, but it is the Agamemnon-clas vz Dreadnought thing.

Those extra batteries did also serve as added protection, though it is hard to measure.
( same Another era: the Rodney/Nelson-class with 3500 tons of 'reserve feed water' aka liquid bulge. )

Don't bluff. It's plenty quiet after it's scrammed. :p
No bluff, I speak from personal experience. It's plenty loud. Then it gets real quiet until the Eng and Captain come in screaming about who caused the fucking scram and critique and so on. Then it gets really loud.

If I remember the construction schematics correctly, those batteries were right next to the hull.
True.

Makes it extra durable I suppose.
No, makes it easy to keep the battery cool, with it being next to seawater and all. Electrolyte gets really hot in the rare event of excessive discharge (like during a casualty) or excessive charge.

But not sure how much more durable since the days of depth charges were long since gone when they made those boomers.
There is still a depth charge casualty procedure though. ;)

And batteries =/= fuel cells.
Agreed.

V/R, the EM1(SS)
EDIT: That's Electrician's Mate, 1st Class, Submarine Qualified

No bluff, I speak from personal experience. It's plenty loud. Then it gets real quiet until the Eng and Captain come in screaming about who caused the fucking scram and critique and so on. Then it gets really loud.

LOL! That's not the sub's fault or the reactors fault.



No, makes it easy to keep the battery cool, with it being next to seawater and all. Electrolyte gets really hot in the rare event of excessive discharge (like during a casualty) or excessive charge.

But doesn't it also serve as an added layer of protection in the event of attacks?


There is still a depth charge casualty procedure though. ;)


Bah, who still uses those things anyways?