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Military / Re: Surface Ships Need More Offensive Punch, Outlook
« Last post by sferrin on Today at 09:28:24 pm »
Wasn't the motivation for two reactors a federated design where one reactor was coupled to one propeller?

It may have been because they didn't have a single reactor available of sufficient power.  That's why Enterprise had 8 reactors, two to a shaft.

; the "medium surface combatant" specs were quite eye-watering.

Damn.  :'(
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Military / Re: Surface Ships Need More Offensive Punch, Outlook
« Last post by marauder2048 on Today at 07:55:53 pm »
Wasn't the motivation for two reactors a federated design where one reactor was coupled to one propeller?

I think in all of the studies over the past decade+ the Navy only looked at single reactor arrangements
typically of the nuclear IPS style; the "medium surface combatant" specs were quite eye-watering.


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The Bar / Re: Southwest airlines #1380 30,000 ft. fan blade failure
« Last post by kcran567 on Today at 04:52:30 pm »
NTSB Chairman Robert Sumwalt said "As the aircraft was climbing through about 32,500 feet, the engine parameters, both RPM indicators on the left engine went down to zero, oil pressure went down to zero, and the engine vibration increased significantly on the left engine," he said.

Shortly thereafter, the cabin altitude warning horn was activated, indicating that the cabin altitude was "going down to about 14,000 feet," said Sumwalt. The aircraft then began an uncommanded left roll at about 41 degrees of bank angle, compared to the normal 20 to 25 degrees of bank that is typical when flying a commercial airliner, such as the 737, according to Sumwalt.

41 deg bank and roll to left is pretty significant, that probably when the debris hit the passenger window, as mentioned above there was a delay when the window was hit after the failure.
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Aerospace / Re: Scaled Composites Model 401
« Last post by George Allegrezza on Today at 03:20:36 pm »
Sweet!
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From "FY19 Air Force Presidentís Budget Request Science and Technology Overview"
Mr. Jeff H. Stanley @ The 19th Annual Science & Engineering Technology Conference

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Military / Re: Surface Ships Need More Offensive Punch, Outlook
« Last post by sferrin on Today at 02:21:34 pm »

Exactly.  That's why I think the Zumwalt is the obvious choice.  It's got the power, the speed, and is available today.

It may or may not have the power for today.  It certainly doesn't have the power for a 35-50 yr ship.  The US is building Ford class with a 100% margin for power.  I don't see 100% margin for power with 'today's Zumwalt.

A cruiser isn't an aircraft carrier.  Furthermore the Zumwalt has a lot more margin, volume wise, than any conceivable Burke variant.  Obviously one could build a Kirov analog but the unit cost would be so high as to be impractical. 

I'm not convinced Zumwalt can carry a Ford class reactor.  So now one has to look at either another existing reactor that has enough power.  Is there one?  If not, then you have to develop a new reactor or make a bigger Zumwalt.  Or - you can use an existing hull with an existing reactor.

Or you do like every other US nuclear surface combatant and use a pair of reactors (which you'd want to do anyway to avoid a single-point-of-failure).  A pair of the reactors being developed for the Columbus class should fit the bill.

The lost opportunity cost is dealing with two solutions, a conventionally powered Zumwalt and a nuclear powered Zumwalt.  It's a waste of time, effort and training.

Ship design - X2
Ship production systems - X2
Ship building - X2
Training of the ship builders - X2

Efficiencies are driven by repetition.  Look at the price management and schedule reduction with Virginia class.  Want to drive the cost down on a cruiser?  Build the same one over and over for 10 years.  Then build it over and over for another 10 years.  The extra production may assist in Ford cost management as well.

In principle I'd agree with you but the USN is trying to reconstitute the fleet ASAP and a flight of conventionally powered Zumwalt-based cruisers will get ships delivered sooner and buy you the time necessary to get the nuclear power worked out.  It's not unprecedented.  The Bainbridge was basically a nuclear powered Leahy.

I've got nothing against Zumwalt.  I'm just not convinced it has the power or size to be a 40-50 year solution as a BMD ship.  You don't either since you propose a nuclear powered "flight ii". 

You're twisting my words.  I am convinced the Zumwalt hull and machinery is the way to go.  I did NOT say, "slap a "CG" in place of the "DDG" and call it good". 

You can't retrofit nuclear propulsion into hulls.  You can retrofit just about anything else in a hull. 

Again, you're twisting my words.  I'm not suggesting you rip the guts out of DDG-1000 to -1002 and convert them to nuclear power.  I'm saying that a Flight II could could be redesigned for nuclear power, and maybe Flight III (or the Flight II) gets the stretched hull mentioned elsewhere in the thread.

Perhaps I'm missing the obvious but I don't see the requirement for 30+ knots.  It would be nice but it's not necessary.  And speed is the only advantage I see with the Zumwalt hull.  All the other advantages I see with a Level 3 San Antonio.

Speed, maneuverability, survivability, cost.  The only advantage a San Antonio would have is it's big.  By the time you've made it into a combatant it would be so expensive you may as well have built the Kirov.
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Military / Re: Surface Ships Need More Offensive Punch, Outlook
« Last post by marauder2048 on Today at 11:25:11 am »
Funnily enough, a notional cruiser design space exploration paper did a include a 12 MW, 450 metric ton laser AAW system.



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Aerospace / Re: Lockheed Martin F-22A Raptor
« Last post by bob225 on Today at 09:50:27 am »
I'm not sure how long the F22 will take to repair but this one was in the hanger for years!
 B)
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Aerospace / Re: Lockheed Martin F-22A Raptor
« Last post by sferrin on Today at 09:27:36 am »
This might need it's own thread. . . .

Exclusive: Lockheed Martin to propose stealthy hybrid of F-22 and F-35 for Japan
https://www.reuters.com/article/us-japan-defence-lockheed-exclusive/exclusive-lockheed-martin-to-propose-stealthy-hybrid-of-f-22-and-f-35-for-japan-sources-idUSKBN1HR0MM

LM Exec #1

PCA is going to be win of the 2020's.  We have to make this happen.  What can we do to better our chances of winning this deal?

LME #2

Hmmm.  Let me talk this through out loud.  If there's already a 80+% solution available... it's likely... that Congress will require it to be used to save on the development cost of a new jet.  At the very least, the developer of such a jet will be favored in the selection process, right?

LME#1

So.  Where are you going with this?

LME#2

What if we were to develop a new jet, say an air superiority version of the F-35 with a greater depth of magazine and longer range AND - here's the kicker - get someone else to pay for it?

LME#1

What?  Who's going to do that?

LME #2

The Japanese!

LME #1 and #2

(Exclamations of realization and slapping each other on the back they exit stage right)

The problem with your hypothetical argument is that the F-35 cannot be made into an air superiority version with deeper magazines.... As good as it is at being a multirole fighter, its physically stuck with AT THE MOST 6 AAMs if Lockheed and the DoD ever make that happen.

The F-16 is used as an air superiority aircraft all over the place and it only carries six.  Six is the standard load for the Rafale, Gripen, and J-10 as well.  Hell, J-10s is 4.  Haven't heard of those being crippled.
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