But, but, but . . . . the argument still stands. Why not generate electricity directly? Why put in the extra, costly, step?
Return of the battleship.
- Thread starter Tankcrewman2008
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Hydrogen (IMHO) really only makes sense when it is transported via ship. It makes a lot of sense in projects where energy is available in a remote location, putting it in a bottle and then taking bottle of energy to where its needed.
That (funnily enough) means it is good for wind where windy places are not normally heavily populated. i.e energy is there but no infrastructure, whether it be solar, wind or geothermal.
If you transport Hydrogen via ship, then what is to say you can't power the ship with it? Makes it easier to transport. If you are powering the ship with it, why don't you take a larger turbine and just plug the ship into the grid when you get to point 'B'
ahhhhhh, I just saved huge infrastructure costs in building a new powerplant.
The ideal market is not Virginia. In fact Virginia is one of the least favorable, but as the numbers worked out there, then that makes the numbers for a more favorable market look really good.... like Europe.
Hydrogen has its place, because if you regard it as energy in a bottle, it basically uses the same infrastructure and know how as the oil and gas industry, which means you save uber bucks on tech transfers and infrastructure costs, plus people "get it"....no loss of labor skill sets and/or experience. "... I've worked in oil and gas since I was knee high to a duck. Now I am working in Hydrogen and the wife is happy..." sort of thing.
and re the thread topic, yes that means creating a war fighting ship of large proportions, but I have argued that the CVN Nimitz and the CVN 21 are too small anyway. They are just big enough to have big ship maintenance costs but too small to get big ship benefits in capability. Make them 200,000 tons or 300,000 tons and they become way more efficient and you start getting into the fabled "sea base" concept.
Oh and armor? Just make it spaced armor or whack in a hydrogen tank and you are good to go.
cheers
w
peterAustralia
Member
I do not think this battleship idea is totally unsound, perhaps has merit if scaled down a bit though.
Some examples, HMS Tiger, 1959-1978, was reconfigured with a large helicopter deck and hangar, capable of carrying 4 Sea King helicopters. The 6 inch guns were capable of 20 rounds a minute each. A large ship at 12000 tonnes, but capable of 31.5 knots.
Could such a vessel serve as the basis of a new build ship? I think so. The large light deck and helicopter capability would certainly be useful in amphibious and humanitarian operations. A large ship could also more easily contain a hospital ward and davits and landing craft to assist in amphibious operations. A large ship with large flight-deck would permit flight operations in higher sea states.
Instead of 6 inch guns, perhaps a modern 8 inch gun could be developed that was highly automatic and carrying base bleed shells to improve range. Additionally with new technology these shells can now be aimed and steered via a small drone with a laser designator. Can the work of Gerard Bull be used to increase the range still further as it has been on land artillery?
As to armour larger ships can have a higher proportion of their structure devoted to armour. In the Falklands several ships were lost that possibly needed not to be. Example one ship was lost to an aircraft firing unguided 57mm rockets. A bigger ship would have the space to divide the superstructure into separate modules so as to better withstand blast effects.
Obviously the designers of these ships were working to the best of their ability but at that time armour was not such a big thing. Where to put armour? the logical places would be around the magazines, the command center, bridge, steering gear, electrical, hydraulic and computer conduits. A rough figure might be a thousand tonnes of armour on a 12 thousand tonne ship.
For larger areas perhaps a lighter armour might be used there, so possibly kevlar armour for engine room and the helicopter hangar. I am no expert on the cost/benefit weight issues and blast and projectile protection of traditional armour vs the modern kevlar equivalent.
If designed to carry a lot of helicopters from the outset, perhaps up to 5 or 6 NH90 class helicopters could be carried in a large hangar aft.
Without going to excess, a degree of armour could greatly assist the survivability of a ship, the ability to withstand a missile attack, withstand a bomb or unguided rocket would all be useful. Obviously a new build ship would be built with modern propulsion, be that gas turbines or diesel or both. Do not know anything about this hydrogen stuff. Automation can reduce the crew needed for a large gun as seen by modern automatic 5 inch guns. A larger ship has a naturally longer fatigue life
On cost, yes it would cost a bit, however most of the cost of modern ships is the electronics and weapon systems. If the ship was armed only with short range anti aircraft and missile protection systems, that would certainly assist
in lowering the price. I think a big battle would be to try and avoid getting items placed in the ship, to avoid the temptation to add an area defence SAM, Anti ship missiles, torpedo tubes, control and command facilities etc.
Such a large vessel would I think be quite complimentary to existing frigates and destroyers. Vittorio Veneto and some large Japanese destroyers show the viability of a large hull with a large helicopter hangar combines with a good gun armament.
Some examples, HMS Tiger, 1959-1978, was reconfigured with a large helicopter deck and hangar, capable of carrying 4 Sea King helicopters. The 6 inch guns were capable of 20 rounds a minute each. A large ship at 12000 tonnes, but capable of 31.5 knots.
Could such a vessel serve as the basis of a new build ship? I think so. The large light deck and helicopter capability would certainly be useful in amphibious and humanitarian operations. A large ship could also more easily contain a hospital ward and davits and landing craft to assist in amphibious operations. A large ship with large flight-deck would permit flight operations in higher sea states.
Instead of 6 inch guns, perhaps a modern 8 inch gun could be developed that was highly automatic and carrying base bleed shells to improve range. Additionally with new technology these shells can now be aimed and steered via a small drone with a laser designator. Can the work of Gerard Bull be used to increase the range still further as it has been on land artillery?
As to armour larger ships can have a higher proportion of their structure devoted to armour. In the Falklands several ships were lost that possibly needed not to be. Example one ship was lost to an aircraft firing unguided 57mm rockets. A bigger ship would have the space to divide the superstructure into separate modules so as to better withstand blast effects.
Obviously the designers of these ships were working to the best of their ability but at that time armour was not such a big thing. Where to put armour? the logical places would be around the magazines, the command center, bridge, steering gear, electrical, hydraulic and computer conduits. A rough figure might be a thousand tonnes of armour on a 12 thousand tonne ship.
For larger areas perhaps a lighter armour might be used there, so possibly kevlar armour for engine room and the helicopter hangar. I am no expert on the cost/benefit weight issues and blast and projectile protection of traditional armour vs the modern kevlar equivalent.
If designed to carry a lot of helicopters from the outset, perhaps up to 5 or 6 NH90 class helicopters could be carried in a large hangar aft.
Without going to excess, a degree of armour could greatly assist the survivability of a ship, the ability to withstand a missile attack, withstand a bomb or unguided rocket would all be useful. Obviously a new build ship would be built with modern propulsion, be that gas turbines or diesel or both. Do not know anything about this hydrogen stuff. Automation can reduce the crew needed for a large gun as seen by modern automatic 5 inch guns. A larger ship has a naturally longer fatigue life
On cost, yes it would cost a bit, however most of the cost of modern ships is the electronics and weapon systems. If the ship was armed only with short range anti aircraft and missile protection systems, that would certainly assist
in lowering the price. I think a big battle would be to try and avoid getting items placed in the ship, to avoid the temptation to add an area defence SAM, Anti ship missiles, torpedo tubes, control and command facilities etc.
Such a large vessel would I think be quite complimentary to existing frigates and destroyers. Vittorio Veneto and some large Japanese destroyers show the viability of a large hull with a large helicopter hangar combines with a good gun armament.
And that's ok for fuel storage on warships or what do you want to say? What storage principle are you talking about?
Well fine, we were looking at such models as well, mostly related to providing supply for fuel cell cars. If you're able to make them real, that's fine, give me a call.
Apart from that: What scale of H2 production are we talking about here? And what timeframe?
Because that's essential, you see. My impression was/is that most of these models are based on a lot of assumptions and a lot of "if"s and apart from the fact that I don't quite comprehend the relevance of Virginia being supplied with clean power in this context, it remains to be seen if these models are realistic. In addition to that most people that provide these clean power scenarios have a certain agenda and those who read those icelandic websites should take a little time and question some of the shiny, fancy stuff.
However, if you are to supply H2 for warship use these days it is bloody expensive. You're a little bit ahead of your time, aren't you.
Yes, I know, you're a defence pro and so on, but during my studies I've worked for 2 years on fuel cell car related topics and this time I know well what I'm talking about. Please respect that.
If you're misunderstanding or have the impression that I have no idea what I'm talking about due to my poor english skilld or have questions, you're invited to ask for clarification via posting or PM, I'll be glad to answer and add information. As you don't know my technical background, please do not make statements like the following:
No, it's not. And it really angers me you're talking like that because obviously you're not in the position to call this grossly incorrect.
To start with, how many years do you think will it take until we'll see production ready SOFCs that will generate the amount of power we're talking about here ("on a large scale"
)? This really is future technology. And still, what's your efficiency factor? Around 50%.
Again, we're talking about one or several fuel cells that provide 60-100 MWs or more for a battleship sized vessel with loads of equipment in it.
Aw man, I know some guys at the thermodynamics institute who would slap you right in the face if you said this to them. Waste heat is a good thing. Ok, if you think so.
Or have there been some breakthroughs in heat recuperation that I didn't hear of that allow you to install the required machinery in a ship with limited space? Around fuel cells that need to deliever 60 or probably more MWs? Do you know how much volume these things need? And what are you then going to use the heat for? To reform natural gas or what? Or use it with a steam turbine or drive a stirling engine?
Again, you're probably talking future technology.
Again, what storage principle are you talking about? In the paragraph I was talking simple storage under pressure, as e.g. for welding application, which would be the simplest possibility I can think of. Essentially, compressed H2. Nothing else, apart from any cavernous, inert filling material. And if you have a leak you have a problem. Period.
I totally lose you here. Hydrogen peroxide? What are you talking about? Well, for the sake of it, let's talk about it. You know what can happen if there are impurities? Or if there is a leak and hydrogen peroxide gets in contact with e.g. copper? Apart from that I'd rather have some litres of diesel over my skin than your H2O2.
And I said chemically bound storage, which perhaps is the wrong term in english. There are ways to store hydrogen safely, yes, but you deal energy density and/or procedural simplicity for that. Period.
My observation is that you're an impertinent person. You're putting together some apples and oranges, believes and future stuff and on this basis you're challenging me in quite a harsh way.
Again, if you have any questions or want to discuss this in a more detailed, factual way, you're welcome. After all, this is not a thread about fuel cell powered ships.
Now for conclusion, you are suggesting that a battleship sized vessel could well be powered by SOFCs generating about let's say 100 MWs of power (that don't exist), fed with H2 produced stored in a way that needs about 3 times the volume than conventional fuel and boosted in their efficiency by heat recuperation small and light enough (which doesn't exist)? And the costs of this roughly equalling a coal powered ship. Did I get it right?
This is OT, but the following remark has to be made: Lately it seems to me that is has become a very common thing here that def pros are acting as if other members didn't know anything, yelling idiot at everyone. That's not correct behaviour!
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Molecular Embedding perhaps?
(i.e. H2 molecules embedded in either a metallic structure or between "sheets" of a carbon-based nanostructure - about the only two ways to store H2 in a chemical structure without binding it straight to another molecule)
Yeah, that's more like it. Thanks.
Agreed. Splitting seawater using solar power on a sunny desert coast, or wind power somewhere wet & windy & desolate, then shipping it far away to use it, does make sense. It was the idea of doing it in a populated area that baffled me.
But we digress . . .
Falstaff, you are the one who unloaded both barrels at the thread starter. I felt it appropriate to call you on some gross assumptions you appeared to have made. If my comments regarding technology have shaken your foundations in education (as it appears to have given you a case of future shock) then I can't really apologize, change and innovation are the nature of the beast. You will come across it sooner, or later.And that's ok for fuel storage on warships or what do you want to say? What storage principle are you talking about?
Well fine, we were looking at such models as well, mostly related to providing supply for fuel cell cars. If you're able to make them real, that's fine, give me a call.
Apart from that: What scale of H2 production are we talking about here? And what timeframe?
Because that's essential, you see. My impression was/is that most of these models are based on a lot of assumptions and a lot of "if"s and apart from the fact that I don't quite comprehend the relevance of Virginia being supplied with clean power in this context, it remains to be seen if these models are realistic. In addition to that most people that provide these clean power scenarios have a certain agenda and those who read those icelandic websites should take a little time and question some of the shiny, fancy stuff.
However, if you are to supply H2 for warship use these days it is bloody expensive. You're a little bit ahead of your time, aren't you.
Yes, I know, you're a defence pro and so on, but during my studies I've worked for 2 years on fuel cell car related topics and this time I know well what I'm talking about. Please respect that.
If you're misunderstanding or have the impression that I have no idea what I'm talking about due to my poor english skilld or have questions, you're invited to ask for clarification via posting or PM, I'll be glad to answer and add information. As you don't know my technical background, please do not make statements like the following:
No, it's not. And it really angers me you're talking like that because obviously you're not in the position to call this grossly incorrect.
To start with, how many years do you think will it take until we'll see production ready SOFCs that will generate the amount of power we're talking about here ("on a large scale"
And still, what's your efficiency factor? Around 50%.
Again, we're talking about one or several fuel cells that provide 60-100 MWs or more for a battleship sized vessel with loads of equipment in it.
Aw man, I know some guys at the thermodynamics institute who would slap you right in the face if you said this to them. Waste heat is a good thing. Ok, if you think so.
Or have there been some breakthroughs in heat recuperation that I didn't hear of that allow you to install the required machinery in a ship with limited space? Around fuel cells that need to deliever 60 or probably more MWs? Do you know how much volume these things need? And what are you then going to use the heat for? To reform natural gas or what? Or use it with a steam turbine or drive a stirling engine?
Again, you're probably talking future technology.
Again, what storage principle are you talking about? In the paragraph I was talking simple storage under pressure, as e.g. for welding application, which would be the simplest possibility I can think of. Essentially, compressed H2. Nothing else, apart from any cavernous, inert filling material. And if you have a leak you have a problem. Period.
I totally lose you here. Hydrogen peroxide? What are you talking about? Well, for the sake of it, let's talk about it. You know what can happen if there are impurities? Or if there is a leak and hydrogen peroxide gets in contact with e.g. copper? Apart from that I'd rather have some litres of diesel over my skin than your H2O2.
And I said chemically bound storage, which perhaps is the wrong term in english. There are ways to store hydrogen safely, yes, but you deal energy density and/or procedural simplicity for that. Period.
My observation is that you're an impertinent person. You're putting together some apples and oranges, believes and future stuff and on this basis you're challenging me in quite a harsh way.
Again, if you have any questions or want to discuss this in a more detailed, factual way, you're welcome. After all, this is not a thread about fuel cell powered ships.
Now for conclusion, you are suggesting that a battleship sized vessel could well be powered by SOFCs generating about let's say 100 MWs of power (that don't exist), fed with H2 produced stored in a way that needs about 3 times the volume than conventional fuel and boosted in their efficiency by heat recuperation small and light enough (which doesn't exist)? And the costs of this roughly equalling a coal powered ship. Did I get it right?
This is OT, but the following remark has to be made: Lately it seems to me that is has become a very common thing here that def pros are acting as if other members didn't know anything, yelling idiot at everyone. That's not correct behaviour!
And for the record, no, I don't think you are an "idiot". If anything your English is good enough that I didn't realize you were a non native speaker, and I replied in kind to your post.
cheers
w
All, Feel free to take the Hydrogen discussion into a new post in the Tech section - but it would be appropriate to stay on topic in here as much as possible.
Again, there's a need to watch how people conduct themselves when discussing things of close importance.
Again, there's a need to watch how people conduct themselves when discussing things of close importance.
it would be too expensive to build a battleship considering the fact that carrier with planes can project their power so much further than battleships can with missiles.
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These seems to be a suggestion the Hydrogen will not explode and is less dangerous than hydrocarbons. This is nonsense. Hydrogen by it nature has a very wide explosive range (4% to 75%) and is lighter than air and has a flash point of -259 degree C and a boiling point 252 degrees C. A number of merchant ships have had hatch covers blown off and been lost (with loss of life) when hydrogen generated as a result of oxidisaton of the cargo (we are not talking large volume here) found a source of ignition (this can be as simple as steel on steel contact with hatch covers). Hydrogen escaping into any space poses a serious risk. Teh attached report is a sobering reminder of the risk.
http://www.register-iri.com/content/artspeeche/IntercargoAsia-B.cfm
Diesel on the other hand as a flash point of greater than 60 degrees C (closed cup) and is not even considered a class 3 dangerous good (it comes in at about 62 degrees C). HFO is even less combustable.
As an aside there are currently no ships designed to carry H2 in bulk and it must be shipped as a refrigerated liquid (See UN1966) when shipped in tank/packaged form. There are compressed gas carriers being considered but these are being designed around natural gas.
200000 to 300000 tonnes will be an interesting design challenge. Assuming a low block coefficient necessary for high speed it will be a very long ship and there will be significant hull strength issues, particualry in a seaway. By way of an example look at the Emma Maersk. This ships DWT is only 157000 tonnes and the ships is 400m long. Noting cargo ships tend to be heavier than warships and the CVN21 is 100000 tonnes dispalcement on 333m the extrapletion to 200000 to 300000 tonnes is daunting.
http://www.shipgaz.com/magazine/issues/2006/16/1606_article.php
I don't really see any use for a ship of such dimensions - even as a carrier.
Despite the large size, you'd run into arrangement problems in carrier operations, unless you keep the embarked aircraft at present numbers - but that would be uneconomical to the max. Think about it - where do you place extra catapults? Elevators? Multiple angled flight decks - because other than that there's pretty much no solution for such problems? Also think for example about the scale of propulsion equipment to bring this carrier to proper aircraft operations speed. Or think of the crew scale.
A battleship of such dimensions runs into similar problems. The size of capital ships has traditionally been driven by two factors weighing in heavily - armament and armor. What kind of modern armament would you envision - a battery of 1000+ VLS cells? Because other than that, there's pretty much zero reason nowadays to go to large scales in ship dimensions. Once you start figuring in the protection package for such a ship though - radar/AAW pickets, ASW ships trailing the seas around it and such - this becomes a moot question; building a handful SSGNs is simply cheaper.
As a seabase - i.e. an integrated package for support of littoral, amphibious and land operations essentially? What for? Sure, i could see MPF ships of such sizes acting in such roles. But, again, there's an economic turnpoint reached - bigger ships always means less ships, and the MPF/Seabase ships are essentially tailored to support a specific externally given force size. Anything beyond that would be excess, and would reduce the possible number of concurrent deployments as well.
The size provides you with a bigger flight deck. The only reason carriers have catapults, wind over deck and angled flight decks is because of size limitations even on a 100,000 tonne carrier. The bigger a ship is the more efficient propulsion power can be and crew size.
The 300,000 tonne carrier could have a flight deck 500m long and 150m wide. This is 1.5 times longer and twice as wide as the Nimitz flight deck. Such a carrier could have two parallel runways and a large central deck park and deck edge elevators.
There have been quite a few serious engineering studies of such large carriers. The biggest problems with them are the same problems that face supertankers, that is the deep draft and problems with docking and navigating shallow waters.
A 150m wide carrier would have to spend its lifetime in deep seas. And not fit into any canals of course. A 3.5-to-1 length to beam ratio with overhangs? Horrible on the likely block factor (or very susceptible to tipping over), and probably damn near immobile.
Oh, and a F-18 has a minimum safe runway length of around 1800 ft for conventional takeoff on land (official requirement: 2300 ft at min takeoff weight). 1400 ft would be "doable", but not safely so without wind over deck. F-35C has similar requirements. Unless we go with the requisite 800m minimum standards that land airfields for conventional-aircraft STOL operations have, we'll need catapults. And at least turning into the wind. And arresting gear. Read: a carrier - not a floating airfield.
Oh, and a F-18 has a minimum safe runway length of around 1800 ft for conventional takeoff on land (official requirement: 2300 ft at min takeoff weight). 1400 ft would be "doable", but not safely so without wind over deck. F-35C has similar requirements. Unless we go with the requisite 800m minimum standards that land airfields for conventional-aircraft STOL operations have, we'll need catapults. And at least turning into the wind. And arresting gear. Read: a carrier - not a floating airfield.
Sure but if anyone was to build such a large carrier they wouldn't be doing so in order to have something nimble for sailing around Danish islands but for sitting 200km offshore with an airwing of 200 aircraft and enough ordnance and fuel to fly them for weeks.
I never suggested the megacarrier could do away with catapults but tried to place some context into your problems with a big ship. With a 500m long deck why not have 250m long catapults? Who needs an extra 30 knots of wind over deck when the catapult can do it?
I find it really strange that someone can think that size is a hindrance to flight deck operations. Lack of size has always been why flight deck operations have been difficult. The USN went to a supercarrier size (USS Forrestal) in order to have a carrier able to operate for more than 66% of the time in rough waters like Arctic waters.
But - the operative question - is there space for a higher number of catapults?
Realistically, carrier operations isn't about whether you have to turn the ship into the wind, but how quick you can get how many aircraft off the deck and into the air afterwards. Larger catapults do not increase sortie rate. Longer runways do not increase sortie rate (unless you can actually use them to take off CTOL at sub-minute launch rates).
Of course there is still some growth margin to achieve perfect operations with the current 4-catapult supercarrier. But beyond that growth margin (pushing a supercarrier by say about 10-20% in all three dimensions) there's simply no reason to grow further.
While you could transport a larger air group, it's not worth it operationally unless you can get a certain number of aircraft into the air within a certain time frame. 200 aircraft on a carrier - well, that's one wing for defensive CAP, three wings on operational rotation for strikes and other offensive operations between maintenance cycles. Questions that immediately pop up are: How long do you need to get 50 aircraft into the air for your strike/escort package (with four EMALS cats, proper wind condition and perfect taxiing it's between 10 and 30 minutes btw)? Do you need 50 aircraft with at a 250% surge rate simultaneously for the assigned tasks (which percentage of strike operations need it and for which percentage in duration of these operations)? Would it be more flexible and cost-effective to have two carriers with 100 aircraft?
Yeah sure. You could easily fit eight catapults alongside each other for a 150m wide flight deck. I don't know how you can think that a huge megacarrier would somehow be a laid out in the same pattern as a current supercarrier or somehow limited in flight deck.
Nice to see you've now gone from 'could never be done' to 'why would you' which of course is a good question and why no one has bothered to grow the size of a super carrier (there is no reason). But if for some operational reason you needed all your air wing eggs in one basket then it would be feasible.
If you look at the new EM cats which are now on final land based evals - I'd say yes at the physical imposition level. They are taking up less space - and that also means that there then becomes a positive for extra available space on issues of bunkerage.
As indicated though - the issue is the volley rate - EM cats will enable faster cycliing, and hence faster launch rates.
Faster smaller cats (real estate) mean nominally:
- bunkerage opportunity
- corresponding impact on weapons lifts
- corresponding impact on fuel storage
- corresponding impact on stowage and maint of aircraft below deck
- an impact on overall lift issues - it does mean that larger lifts can also be used. That would mean a change in basic aircraft foldaway engineering, but it could also mean lifting multiple UCAV/UAVs at a time
- corresponding impact on taxi queues
- corresponding impact on recovery rates as aircraft can be parked off deck without effecting launch and recovery rates
Personally, I'm not a fan of sea-basing sized platforms, but thats neither here nor there anyway.
And they "only" needed to switch to a completely new reactor/turbine design to power that, as they can't use the steam directly any more and instead now need to draw 11 MW extra in electric power just for EMALS... (the steam turbines on the two reactors of a Nimitz produce 64 MW total).
The new super conducting engines (and they're already commercial) have 1/3rd the equivalent weight, almost 1/3rd less volumetric mass and close to double the output.
These engines are seriously in consideration for future submarines due to some inherent advantages.
again, one of the huge plusses for the SC engines is a bunkerage release. More real estate means more warfighting space and greater ability to stay and fight longer as more aviation fuel, more weapons and more sophisticated energy intensive ewarfare/sig management systems can be employed.
These are "here and now" engines, so not a buck rogers scenario.....
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