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USS Zumwalt, DDG-1000, complete 2nd US Navy acceptance Trials
FR | May 11, 2016 | Jeff Head

Posted on 05/11/2016 9:06:31 AM PDT by Jeff Head

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To: Mariner

I admit to feeling much the same as you, but in reality, you would be quite astonished at just how small the radar signature is for a correctly designed vessel like that.

I read a book “Skunk Works” recently about the development of the F-117, and it was fascinating (recounted by Ben Rich, who ran the Skunk Works for a couple of decades)

in the book, he talked about how they calibrated the radars they were using in their stealth experiments, and he said (I know this sounds really hard to believe, but it is what he said in the book) that they had models to test the concept, and the could detect a metallic object the size of a BB (that is a BB gun BB, not a battleship BB!) five miles away!!!!!

In one high profile test, they had a bunch of bigwigs in, and to their disappointment, they were able to see the target model on their radar when they had believed they wouldn’t. It turned out a bird had landed on top of the model, and that was what they were picking up.

One of the surprising things was that early on, they found that the size of the object was not an issue, it was the shape. I don’t have the book at my disposal right now, but according to the math, and according to the data, the concepts that worked on an F-117 with the right shape worked exactly the same on a ship the size of a large naval vessel. Hard to believe, but that is what the testing showed.

The way Ben Rich described it, a standard frigate had the radar cross section of 50 barns, but their concept ship would have the cross section of a dinghy. (in his words)

In one experiment back in 1985, they had constructed a 500 ton stealth ship (I think they called it the Sea Shadow) that was about 70 feet wide, using these same concepts, and took it out on the ocean. They had P3 Orions using their radar they normally used to detect surface ships, and to be sure it was working correctly, had fake periscopes dropped in the water that the P3 could easily pick up.

On one night, they made 57 passes at the ship at night, and only saw it on their radar twice, both times when they were about a mile and a half away. They even provided the exact location of the vessel to the pilots, and they still couldn’t see it.

But as we know, the problem with stealth is that it has to match the background. If it is LESS visible than the background, it becomes visible as a “hole”. That was the problem they had with the Sea Shadow, was that the wake it made was more visible than the vessel itself.

And there are other ways, as we now know, that stealth can be defeated. But it is still an impressive feat. Ben Rich said Lockheed did a preliminary concept plan for an aircraft carrier that had the radar cross section of a life raft. I know it sounds insane, but that is what he said. It goes back to the concept that the size is not important, it is the shape.

Very interesting read.


61 posted on 05/11/2016 7:57:15 PM PDT by rlmorel ("Irrational violence against muslims" is a myth, but "Irrational violence against non-muslims" isn't)
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To: rlmorel

Thanks for your post on stealth objects.

More on Sea Shadow(IX-529):

https://en.wikipedia.org/wiki/Sea_Shadow_(IX-529)


62 posted on 05/11/2016 8:02:49 PM PDT by exit82 (Road Runner sez:" Let's Make America Beeping Great Again! Beep! Beep!")
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To: Mariner

The Zumwalt has a very different mission profile than the Burke.

The Burke is a multi-role, air defense destroyer.

The Zumwalt is a multi-role fire support destroyer.

Very different set of missions for the primary role.


63 posted on 05/11/2016 8:05:15 PM PDT by Jeff Head (Semper Fidelis - Molon Labe - Sic Semper Tyrannis)
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To: exit82

I don’t know if I got all the details exactly right, because I read the book about six months or a year ago, but I remember reading it and thinking it was batsh*t crazy! It made my mouth drop open...

There was a lot in there as well about the U-2 and the SR-71 that brought out the geek in me!


64 posted on 05/11/2016 8:06:54 PM PDT by rlmorel ("Irrational violence against muslims" is a myth, but "Irrational violence against non-muslims" isn't)
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To: Jeff Head; markomalley; DYngbld; TADSLOS; xsrdx; big'ol_freeper; Mark17; mikefive; JDoutrider; ...

Active Duty ping.


65 posted on 05/11/2016 8:07:12 PM PDT by Jet Jaguar
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To: rlmorel

Actually, I am not sure it was the wake of the ship, but perhaps the general noise level from rough seas that made the vessel visible in tests...I think.


66 posted on 05/11/2016 8:12:59 PM PDT by rlmorel ("Irrational violence against muslims" is a myth, but "Irrational violence against non-muslims" isn't)
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To: GMMC0987
Funny...for many years, I never knew that they did simply lower gun turrets into ships, and that it was often just gravity that kept them in place, even on battleships.

I had one of those weird "Huh...what the..." when I saw the images of the Bismarck sitting upright on the bottom of the Atlantic with those big gaping holes where her big gun turrets used to be!

Kind of like in "Ferris Bueller's Day Off" where he pretends to be the girl's father picking her up at school and lays a full lip lock on her, and the principal mutters "Huh...so THAT'S how it is in their family..."


67 posted on 05/11/2016 8:23:24 PM PDT by rlmorel ("Irrational violence against muslims" is a myth, but "Irrational violence against non-muslims" isn't)
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To: DaxtonBrown

As the destroyer is executing a turn to port, the bow is moving forward and laterally to the ship’s port or left side at the same time, causing water to stack against the side of the bow on the inside of the turn...

But you may be correct in misgivings regarding the design of the “tumblehome” bow...Lots of skeptics and some warnings from “old salts” and naval architects about problems at certain speeds in following seas...And small crew being inadequate for damage control if/when the ship is hit in combat...Also over reliance on unproven software...

Maybe the designers, engineers and brass who pushed this design should form a crew and take her into a Cat5 typhoon as proof of concept before any sailors’ lives are put at risk?


68 posted on 05/11/2016 11:29:26 PM PDT by elteemike
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