747400sp From United States, joined Aug 2003, 1700 posts, RR: 2 Posted (2 months 4 weeks 1 day 21 hours ago) and read 2694 times:
With all the bad feelings Japan has about having the GW being base in there port due to it's Nuclear propulsion, I wonder, could a carrier between a Kitty Hawk and Nimitz class carrier sizes or even bigger than a Nimitz class carrier, been design with 8 or more LM 2500 or LM 5000. Eight LM 5000 would be more than enough to keep a 110000 ton ship speed up with a Nimitz class ship. A gas turbine powered super carrier could have easily replaced the Kitty Hawk. I know Nuclear is a better option due to fuel saving, but could there have been a TG powered carrier to replace the Kitty Hawk?
Rwessel From United States, joined Jan 2007, 596 posts, RR: 0 Reply 1, posted (2 months 4 weeks 1 day 19 hours ago) and read 2649 times:
Sure you could. And four or five LM6000s would also be a heck of a lot smaller (and less trouble to live with) than a pair of A4Ws. It'd be a darn sight cheaper to build too.
But you give up a huge amount of range and time on station, since you're now having to lug fuel for the carrier as well as the (very fuel hungry) aircraft. Or accept that you've always got an oiler tagging along.
This was basically what happened with the Kennedy, which is basically a conventionally powered Kitty Hawk. Although the Kennedy used steam turbines instead of gas turbines (that ends up being rather bulkier than gas turbines, but somewhat more fuel efficient).
Given the amount of electricity generated in Japan by nuclear means (about a third now, planned to increase to over 40% by 2015), the opposition to nuclear propulsion is a bit puzzling. Although there's a fair bit of opposition to nuclear electricity generation as well.
DfwRevolution From United States, joined Mar 2004, 7691 posts, RR: 55 Reply 2, posted (2 months 4 weeks 1 day 18 hours ago) and read 2616 times:
Quoting Rwessel (Reply 1): Given the amount of electricity generated in Japan by nuclear means (about a third now, planned to increase to over 40% by 2015), the opposition to nuclear propulsion is a bit puzzling
Indeed. The U.S. Navy probably has the best safety record of anyone in the world when it comes to nuclear power, civilian utilities included. The Navy has operated over 150 nuclear-powered vessels since 1954 with zero nuclear incidents.
BladeLWS From United States, joined Dec 2005, 265 posts, RR: 0 Reply 3, posted (2 months 4 weeks 1 day 16 hours ago) and read 2582 times:
For a ship that size to be fueled by conventional means is no efficient for military use. You need to put all that fuel somewhere and they adds weight and takes of space for other stuff.
A super carrier needs to be able to have the range, on station time, and sustainable speed in a battle environment. Having to tag an an oiler behind makes that oiler a sitting duck for anyone wanting to stand a carrier in a hostile operations area.
Ken777 From United States, joined Mar 2004, 1958 posts, RR: 0 Reply 4, posted (2 months 4 weeks 1 day 15 hours ago) and read 2569 times:
I served on the USS Long Beach during her first two deployments to WestPac during the Vietnam War. When we left long Beach (out home port) we basically set our course and turned up the speed. It taught me a pretty powerful lesson - a nuclear powered ship can be deployed and can move great distances rather fast, without the burden of refueling.
The only tactical disadvantage is the need for long term planning. On our second deployment is was calculated that if we keep our speed down a bit and limit travel a bit it was possible to get another deployment out of her before re-coring the reactors. That didn't keep us from an R&R trip to Perth (where I met my wife), but it did show the need for long term planning.
Rwessel From United States, joined Jan 2007, 596 posts, RR: 0 Reply 5, posted (2 months 4 weeks 1 day 14 hours ago) and read 2562 times:
Quoting Rwessel (Reply 1): This was basically what happened with the Kennedy, which is basically a conventionally powered Kitty Hawk. Although the Kennedy used steam turbines instead of gas turbines (that ends up being rather bulkier than gas turbines, but somewhat more fuel efficient).
OK, I'd like to totally rewrite that... Other than a total brainfade, I have no explanation.
The Kennedy is basically an upgraded Kitty Hawk (some people consider it the same class, some not), but it was laid down as a nuke (the rest of the Kitty Hawks are conventionally powered), using four A3Ws. The cost of the Enterprise (and Long Beach) caused the Kennedy to be finished with a conventional steam power plant instead.
Moo From Falkland Islands (Malvinas), joined May 2007, 2610 posts, RR: 7 Reply 6, posted (2 months 4 weeks 1 day 7 hours ago) and read 2464 times:
The new Royal Navy carriers will be powered by Rolls-Royce Marine Trent MT30 36 MW gas turbines - two of them, I think.
Quoting DfwRevolution (Reply 2): The Navy has operated over 150 nuclear-powered vessels since 1954 with zero nuclear incidents.
Oooh, don't say that!
1972 - 500 gallons of radioactive coolant was accidentally released into the Thames river, near New London, Connecticut, while being transfered from USS Dace to the submarine tender USS Fulton.
1975 - Sturgeon-class submarine USS Guardfish was contaminated with radioactive coolant residue after dumping it overside and having the wind blow it back. This had happened several times before and the dumping of coolant at sea was discontinued.
1975 - Submarine tender USS Proteus discharges radioactive coolant into Apra Harbour, Guam.
1978 - USS Puffer accidentally released 500 gallons of radioactive water into Peuget Sound.
Now, they aren't huge accidents, but they are accidents.
KiwiRob From New Zealand, joined Jun 2005, 218 posts, RR: 0 Reply 10, posted (2 months 4 weeks 22 hours ago) and read 2295 times:
Think Queen Mary 2, it's 50% heavier than a Nimitz, tops out at 30 knots if you dropped it's proplusion system into a lighter hull it should easily be able to propel it to CVN like speeds. I was told the CVF designers in the UK looked at using the same system as Queen Mary but for some reason decided against it.
747400sp From United States, joined Aug 2003, 1700 posts, RR: 2 Reply 11, posted (2 months 4 weeks 14 hours ago) and read 2194 times:
Quoting KiwiRob (Reply 10): Think Queen Mary 2, it's 50% heavier than a Nimitz, tops out at 30 knots if you dropped it's proplusion system into a lighter hull it should easily be able to propel it to CVN like speeds. I was told the CVF designers in the UK looked at using the same system as Queen Mary but for some reason decided against it.
They should gone with it. The CVF much lighter than the QM2, so if the QM2 can reach 30 knots, imagine how fast a ship that is more than two times lighter, could cruise on the QM2 engines.
Alien From Afghanistan, joined Mar 2008, 362 posts, RR: 0 Reply 12, posted (2 months 4 weeks 13 hours ago) and read 2176 times:
Quoting KiwiRob (Reply 10): Think Queen Mary 2, it's 50% heavier than a Nimitz,
No it is not. QM2 Displacement apx. 76,000 tons, Nimitz clas apx 95,000 tons.
Quoting KiwiRob (Reply 10): I was told the CVF designers in the UK looked at using the same system as Queen Mary but for some reason decided against it.
It was dropped for two very good reasons. Much reduced resilience to battle damage and relatively unproven design.
Quoting Rwessel (Reply 5): but it was laid down as a nuke
No, Congress debated whether it should be a nuke prior to construction. They decided to burn dead dinosaurs rather than split atoms before the JFK was laid down.You don't just plunk boilers into a hull on a whim.
Say it. There has never been an incident of any consequence.
Quoting 747400sp (Thread starter): I wonder, could a carrier between a Kitty Hawk and Nimitz class carrier sizes or even bigger than a Nimitz class carrier, been design with 8 or more LM 2500 or LM 5000. Eight LM 5000 would be more than enough to keep a 110000 ton ship speed up with a Nimitz class ship.
With enough money and enough compromise anything is possible. This is one that you don't to do. If the Japanese don't like it you can always base the fleet, the Marines and the money they pump into the local economy at Guam.
It's not just range. Where do you get the steam to run the catapults? How do you trunk the uptakes, exhausts, insulation and attendant exhaust chillers through the hanger deck and vent it without interfering with flight operations?
StealthZ From Australia, joined Feb 2005, 3473 posts, RR: 32 Reply 13, posted (2 months 4 weeks 10 hours ago) and read 2128 times:
Quoting Alien (Reply 12): No it is not. QM2 Displacement apx. 76,000 tons, Nimitz clas apx 95,000 tons.
Difference is not so great, QM2 is 76,000 Tonnes and Nimitz class approx 95,000 short tons or aprox 88,000 Tonnes
But other points are valid.
Despite what some think QM2 is not turbine powered but is of a CODAG-Electric design. Combined Diesel and Gas turbines driving electric systems.
The turbines are only used to provide the extra power for high speeds and do not run all the time.
Further to Alien's point of where do you put all the uptakes, exhausts etc for the turbines, this is an issue in liners as well. QM2 solves this in a way not especially convenient to carrier opps, the turbine engines are housed on the top deck at the foot of the funnel.
The proposed RN CVF also use a CODAG-Electric system but they will not have the steam plant requirements that current USN CV ops require.
Cheers
Of course old planes are safe, how do you think they got to be old?
Moo From Falkland Islands (Malvinas), joined May 2007, 2610 posts, RR: 7 Reply 14, posted (2 months 4 weeks 1 hour ago) and read 2038 times:
Quoting Alien (Reply 12): Say it. There has never been an incident of any consequence.
I certainly disagree with this, every single one of the incidents I highlighted were 'of consequence' because there were high levels of radioactivity released during each and every one of them.
Now, in the context of this thread, each and every one of those incidents strengthens Japans position, especially considering the latest incident may have resulted in radioactivity being released in their own port.
I'd love to hear what you think would constitute an 'incident of consequence' if releasing high levels of radioactivity isn't...
Quoting Alien (Reply 12): It's not just range. Where do you get the steam to run the catapults?
You boil it. Its not rocket science.
Or you stop using steam - the Royal Navy CVF program has a contigency to be converted to electromagnetic catapults if so required.
Quoting Alien (Reply 12): How do you trunk the uptakes, exhausts, insulation and attendant exhaust chillers through the hanger deck and vent it without interfering with flight operations?
You direct them up through the islands - as the CVF design does indeed do.
Mortyman From Norway, joined Aug 2006, 963 posts, RR: 1 Reply 15, posted (2 months 4 weeks 1 hour ago) and read 2031 times:
The new Royal Caribbean cruiseship Oasis of the seas has the weight of a Nimitz class aircraft carrier and then some... from what i can understand:
Class and type: Oasis Class cruise ship
Tonnage: 220,000 GRT
Displacement: app. 100,000 tons
Length: 1,181 ft (360 m)
Beam: 154 ft (47 m)
Height: 213 ft (65 m) above water line
Draft: 30 ft (9 m)
Decks: 16 Passenger Decks
Installed power: 8 Wärtsilä V12 Engine @ 17,500 hp each
Propulsion: 3 × 20 MW Asea Brown Boveri Azipod, all azimuthing
Speed: 20.2 kn (37.4 km/h/23.2 mph)
Capacity: 5,400 passengers double occupancy (about 7,300 including third and fourth passengers)
Johns624 From United States, joined Jul 2008, 223 posts, RR: 0 Reply 16, posted (2 months 4 weeks ago) and read 2020 times:
Quoting Alien (Reply 12): If the Japanese don't like it you can always base the fleet, the Marines and the money they pump into the local economy at Guam.
End of discussion-there's the answer. With Japan building up her armed forces, we should let them take over more of our Asian responsibility. Everyone has been dumping on the Germans for not coming to the fore, but the Japanese have been skating for much longer...
CURLYHEADBOY From Italy, joined Feb 2005, 808 posts, RR: 1 Reply 18, posted (2 months 3 weeks 6 days 20 hours ago) and read 1939 times:
Quoting Moo (Reply 14): Neither of your issues are exactly show stoppers.
I believe the real show-stopper is strategy.
As correctly pointed out by a poster above, nuclear power means you don't have to refuel.
As a consequence, an immensely valuable strategic asset which a carrier is, can have unlimited range, can sail at high speeds without considering fuel consumption and (possibly the most important thing) doesn't have to rely upon a tanker ship or friendly harbor, so that the enemy can't wipe you out of the operations theatre just by cutting your fuel supplies.
Nuclear has its own disadvantages, and probably is not the most cost-efficient solution, but a supercarrier is a class of its own, and for what it's worth it, nuclear is the best solution.
My 2 cents
If God had wanted men to fly he would have given them more money...
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