Yes, the shapes of a submarine's propellers is classified... Why? I don't know for sure. But I can assume it has something to do with the sub's cavitation... There is a reason why the submarine service is called the silent service...
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Submarine Screws
FUROR OVER SALE CASTS A SPOTLIGHT ON RACE FOR SILENCE IN SEAS By MALCOLM W. BROWNE - NYTimes.com
Hope it helps
Although an older article, it explains the principles of Submarine Screws (Propellers) Design and function and therefore the reason why they are so closely guardedYes, the shapes of a submarine's propellers is classified... Why? I don't know for sure. But I can assume it has something to do with the sub's cavitation... There is a reason why the submarine service is called the silent service...
FUROR OVER SALE CASTS A SPOTLIGHT ON RACE FOR SILENCE IN SEAS By MALCOLM W. BROWNE - NYTimes.com
Hope it helps
Yet another example of why such articles shouldn't be written by journalists without technical background, the way cavitation is explained gives everyone with a basic thermodynamic education a headache.
Until here, he's right. Although one should add that the "suction" effect stems from the fact that due to mass conservation issues a low pressure area is created on the upper surface (what he calls "front surface") of the blade. And then...nytimes said:
Now this is explained stupidly, the real explanation being that water under low pressure simply starts boiling, it vaporizes. Those bubbles aren't vacuum bubbles, they're steam bubbles.nytimes said:
Therefore every effort to avoid cavitation revolves around how to avoid any blade areas entering critical pressure/temperature regimes.
This certainly has got to with speed, but I could design you a blade that cavitates at very, very low speeds.
this is completely off topic of the collins class but i was wondering if anyone knew what the RAN was going to do for their 100th anniversary?
Now, considering for their 75th anniversary in 1986 the RAN had a fleet entry through Sydney heads consisting of 26 vessels from 7 countrys i imagine the 100th will be big.
Anyone on the inside have any information?
Now, considering for their 75th anniversary in 1986 the RAN had a fleet entry through Sydney heads consisting of 26 vessels from 7 countrys i imagine the 100th will be big.
Anyone on the inside have any information?
Looking at a prop you can also proberly estimate maxium speed and maxium silent speed.
Falstaff I also got a shiver reading that article. Suction? As soon as people start talking about liquid fluids they go all giddy. Using simular words would he describe how an aircraft wing works by "suction"?
Falstaff I also got a shiver reading that article. Suction? As soon as people start talking about liquid fluids they go all giddy. Using simular words would he describe how an aircraft wing works by "suction"?
Will a canberra class be ready by then?
the way i understand it the Hull leaves spain around march 2011 but does'nt arive in australia for final fit out till 2012.
So sadly, no
Not to metion the AWD's dont start coming in till 2014.
Mate I know what you mean ! The article was an example of the secrecy behing sub props and the science and effort that goes into it, was not put forward as a true statement but an example so people can have an idea of why their props are so secret. Also Stingray I think you would be right it could give away potential speeds etc, but also more importantly maybe even an indication of the potential noise signature of the vessel ? Not a good thing to give them any information on what to listen for
I didn't mean to come down hard on you, I actually thought it was an entertaining read, I'm just fed off with all the inaccuracies in even respectable publications like the NYTimes. As somebody without the privilege to have access to insider information you just don't know what to believe, caught between company marketing, military secretiveness and dilettante journalism. Sigh...
Bugger. I wonder if the spanish one will make a trip? Still I wonder where the hull will be? Transit?
No doubt. You would have a pretty good idea of what a sub would sound like just by looking at the blades, the angles etc. You start to working a basic idea of what it can do and how to identify it.
A Spanish Armada F100 has already visited Australia on its round the world trip.
So theres nothing to say that one wont come for a visit.
All good mate, I know you were just pointing it out, it was about the only half truth I could find about the subject. I think most of us take what Journo's write with a pinch of salt, afterall if they were the experts they think they are on the subject they would not be talking about it they would be doing it and getting paid a hell of a lot more than they are now !!
If you are interested here is a link on the events of the 75th in 1986, it is a first hand account and describes all the events of the review. I remember this well, it was the year before I joined the RAN. In the post he points out what happened on the open day !! Maximum expectaion was for a crowd of 150,000 and over 300,000 people turned out to see the likes of the Mighty Mo !
RAN’s 75th Anniversary Naval Review - World Naval Ships Forums
I would imagine the 100th should be far superior ? Would be nice if we could get the Spanish Navy to send the JCI along with a F100 ?
I have also sent an email to the RAN History section asking for any information regarding the 100th and suggested they maybe add a link on thier website with the current intentions and updates as to its progress, will post the reply
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RAN 100th Flicker photo's
This is AWSOME, check this out if you have even the slightest interest in the RAN !!!!! An incredible photo history of the RAN in the lead up to the big 100
Flickr: Kookaburra2011's Photostream
This is AWSOME, check this out if you have even the slightest interest in the RAN !!!!! An incredible photo history of the RAN in the lead up to the big 100
Flickr: Kookaburra2011's Photostream
I also found something today similar, they have a media company appointed to make the special magazine for it, so looks like the ball is rolling
very limited unless there is a fundamental shift in the ADFs thinking.
It is slightly more likely we will see occaisional use by allies F-35B (most likely USMC) but agaim this would be rare.
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time will tell...ecspecially if this turns out to be aus returning to carrier operations by stealth.
ovbiously their fuel/munition bunkerage can be enhanced.
extra hull/s ordered.
see what eventuates.
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