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Author Topic: Visby has been proved to be the ghost it's said to be!  (Read 2968 times)

AlexKall

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Visby has been proved to be the ghost it's said to be!
« on: September 19, 2007, 09:46:03 »

The Visby Corvette has been "proved" to be that ghost it's said to be. The Visby is a ship by the way, this is what it looks like:

http://www.marinen.mil.se/visby/index.php?lang=S&c=news&id=31477

Anyways here's what I was refering to:

"Even without the stealth optimisation planned for the SP project, Elofsson added, it can be said that the signature reductions achieved on the Visby class have been impressive. "The crew of Helsingborg experienced this during their transit through the English Channel when they were contacted by the UK radar surveillance centre at Dover who picked up the ship's AIS transponder signal, but did not see the corvette on radar despite the fact that Helsingborg did have some radar reflectors deployed to artificially enhance its radar cross-section." In order not to compromise safety, the ship decided to put up additional radar reflectors, Elofsson claimed, while Dover issued a radio warning to all ships in the area about the presence of the stealth ship."

Srouce: http://www.janes.com/defence/news/idr/idr061204_1_n.shtml.

Finally something that shows it's capability! :)
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[MPSS]AlexKall

marcstrat

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Re: Visby has been proved to be the ghost it's said to be!
« Reply #1 on: September 19, 2007, 14:55:15 »

Greetings,
Is it that not 1 of the vessels,with the waterjet engines.
I it does i've seen a documentory about this vessel,it stops at full power forward,in les than 4 sec.
Amazing vessels you have in the north,realy good thinking of those qualyfide people,maybe we belgian can learn from this,for future designes in the navy.
Regards
Marc
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AlexKall

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Re: Visby has been proved to be the ghost it's said to be!
« Reply #2 on: September 19, 2007, 15:59:07 »

It does indeed have waterjet, here's an image (not mine) of the waterjets.

http://i26.photobucket.com/albums/c144/pbsyte/DSC00263.jpg

Had no idea that it could stop in 4 sec, but I did remember reading that it directed the jet forward when slowing down so it might very well be the case! :)
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[MPSS]AlexKall

clanky

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Re: Visby has been proved to be the ghost it's said to be!
« Reply #3 on: September 19, 2007, 16:35:29 »

Water jets have an incredibly quick power delivery and deliver the same ammount of power no matter what the relative speed of the vessel which means that the ship accelerates or decelerates very quickly.

With a propeller if you apply ahead power to a ship at standstill the propeller will "slip" and not provide full power so the ship will not accelerate as quickly.

The same thing (even more so) will happen if the ship is travelling full ahead and the engines are put full astern, in fact with most ships they will slow down quicker if the engines are put dead slow astern to start with than they will at full astern.
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AlexKall

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Re: Visby has been proved to be the ghost it's said to be!
« Reply #4 on: September 20, 2007, 08:02:01 »

Water jets have an incredibly quick power delivery and deliver the same ammount of power no matter what the relative speed of the vessel which means that the ship accelerates or decelerates very quickly.

With a propeller if you apply ahead power to a ship at standstill the propeller will "slip" and not provide full power so the ship will not accelerate as quickly.

The same thing (even more so) will happen if the ship is travelling full ahead and the engines are put full astern, in fact with most ships they will slow down quicker if the engines are put dead slow astern to start with than they will at full astern.

Very interesting information there Clanky, had no idea that it can be quicker to slow down by not putting it full astern. :)
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[MPSS]AlexKall

marcstrat

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Re: Visby has been proved to be the ghost it's said to be!
« Reply #5 on: September 20, 2007, 08:59:22 »

Greetings,
Yes,i think this documentary was on NGC(national geographic channel).However i cannot remember the programs name.
When i saw that,i was thinking,when you're at the wheel of that vessel,and you have to make a emergency brake,at full power forward.Your face must be very close to the front window.
It was just amazing how fast this vessel could stop.If you have the change,to watch this docu,i'm sure you would be amazed to.
Regards
Marc
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strassenkreuzer

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Re: Visby has been proved to be the ghost it's said to be!
« Reply #6 on: September 20, 2007, 13:17:04 »

I`ve seen one at my last hollydays in sweden. It was very fast...
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AlexKall

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Re: Visby has been proved to be the ghost it's said to be!
« Reply #7 on: September 20, 2007, 17:34:08 »

Thank you for the image there Strass! And I do remember that doc now, was featuring the norwegian stealth wessel aswell  :)

Also love this one:

http://youtube.com/watch?v=jzfqxmHpxfU&mode=related&search= Video of it in the amazon river (they have great navigational skills manuvering it through the amazon river :))

One of the things I like the most is the crash stop which you saw in that video above, it can do a full stop from it's highest speed in 2 to 2.5 boat lenghts :)

Can see it better in this one at 2:44:

http://youtube.com/watch?v=A-8NHfAYEK8&mode=related&search=
« Last Edit: September 20, 2007, 17:51:56 by AlexKall »
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