I remember reading a news article which said that the american continent was floating I think it was on the somewhere at www.bbc.co.uk I've been searching for the article but cant find it.

I think they did some seismic tests and concluded that it was floating on something, cant remember if they thought it was water or something similar though......

In my personal opinion, its possible that an ocean could exist under the surface of the continent. afterall, we know more about space than we do about whats in the earths oceans.

Originally posted by schuyler

Wonder how the Thresher got from the east coast to California in less than 24 hours.

I doubt if we will ever know.

Although the top speed of the subs is classified, even rumor has them going about 50 tops.

Aircraft carriers go faster than that. I believe about 65 knots. The new subs go almost twice that now that they have boundary layer control.

Thanks for the post.

Originally posted by johnlear
Aircraft carriers go faster than that. I believe about 65 knots. The new subs go almost twice that now that they have boundary layer control.

Well, John, I've heard the rumors of 70 for as much 40 years, but my information would suggest the CVNs (modern Nimitz class carriers) can do as much as 42. They put out a rooster tail like a hydroplane when they decide to put the pedal down. The fast combat support ships such as USS Camden also put out a rooster tail. They have to keep up with the big boys to keep them supplied with soda pop and munitions. However, since they burn oil, they have to get permission to go fast; the nukes don't care. They can do top speed 24/7, and THAT'S the advantage. Camden, ported in Bremerton, was decommissioned a couple of years ago. I know many sailors who have served on her.

Thresher was old technology by three generations compared to the fast attacks like the Virginia class we have today. There is also a Sturgeon Class whiich is big and expensive, but only a few were built. We also have quite a few Los Angeles class (+ 2 generations) still in commission. The 'official' top speed of the Virginia class underwater is 32 knots. (Yes, yes. I know.) Top 'rumor' speed is 42 knots.

Originally posted by Fett Pinkus
dont remember the thread when John said exactly that? shame on you

Jury is still out on 911 But then you know that everything John says is dis info



Ach du Lieber...

Aircraft carriers go faster than that. I believe about 65 knots. The new subs go almost twice that now that they have boundary layer control.

Thanks for the post.




I got out of subs in '03 but I have never in my life heard of "layer control" as a propulsion..? Never heard of a sonar dome that could sustain over 60kts..?! This they used as a replacement on seawolf on up after they collapsed the standard grp dome around 50kts. otherwise this is off the chart. any new specs i could look up?

[edit on 17-9-2007 by DIRTMASTER]

That article does not mean crap, man. Think it through. It was done by a science writer, and boasted nothing but wishing thinking about a potential future possibility. Nothing different than 50 years of popular Science covers that have commercial space planes on the "horizon" for the last 40 years and other things that do not come to fruition. Must we go through each and every issue of that and say anything that did not make it, either became a secret black project cover-up and exists today, or merely that the the idea never had enough financial backing and the technological limits at the time were a little to be to be profitable?

Originally posted by IgnoreTheFacts
That article does not mean crap, man. Think it through. It was done by a science writer, and boasted nothing but wishing thinking about a potential future possibility. Nothing different than 50 years of popular Science covers that have commercial space planes on the "horizon" for the last 40 years and other things that do not come to fruition. Must we go through each and every issue of that and say anything that did not make it, either became a secret black project cover-up and exists today, or merely that the the idea never had enough financial backing and the technological limits at the time were a little to be to be profitable?

Thanks for your post and your opinion IgnoreTheFacts. Although I think your grammer, adjectives and vocabulary are not college level neither are mine sometimes.

Thanks again.

Originally posted by DIRTMASTER

I got out of subs in '03 but I have never in my life heard of "layer control" as a propulsion..?

I hope Mr Lear will not mind me commenting on this, but as he said, it's "boundary layer control", not "layer control". I don't read Mr Lear's statement to imply that it is a method of propulsion in and of itself. It isn't.

To explain, "boundary layer" is simply a term used in fluid dynamics (air and water both being fluids, if you will), and it refers to the region (or layer) proximal to contact between a fluid and a surface. One of the problems that has bedevilled humankind since we first started constructing boats (and later aircraft and subs) is the turbulence that is created in this layer where the surface of a craft and the fluid interact.

"Streamlining" is a simplified concept of "boundary layer control", where efforts are made to allow the object to pass through the fluid with the lowest amount of turbulence and coefficient of friction. This has been an especially tough nut to crack in terms of subs because not only does the entire vessel spend much of its time submerged but also needs to function with reasonable stability and maneuverability when on the surface (and so only partially submerged), it is also beneficial for the sub to be able to obtain a high rate of knots when underwater in relation to its mass and the power it has available for propulsion.

After a huge amount of research, various types of improvements have been made to controlling the interaction in this boundary layer, all of which give the vessel significantly higher top speeds per unit of power input into the system and (very importantly) generate less sound.

If you search "boundary layer control" as a phrase with "submarine" you will find some very interesting documents. The ones that relate to electromagnetic and electrostatic boundary layer control systems are especially worth a look.

In regards to propulsion, it is true that older-generation methods (screws) are very inefficient; though not a lot is floating around on the web that is verifiable, it seems that vastly better boundary layer control -based propulsion systems are either in use or being tested.

If you consider the relative performance of a jetski to a conventionally driven craft you'll get what I mean. Not the same thing but the line of thinking is quite similar.

In this case, the problem was not building such propulsion units. It was making them work (by pushing water backwards relative to direction you want the sub to go) in such a way that turbulence did not negate the advantages of thrust they produce, or did not produce sound that could be identified as a "fingerprint" of the vessel.

Mike

Originally posted by johnlear

Originally posted by IgnoreTheFacts
That article does not mean crap, man. Think it through. It was done by a science writer, and boasted nothing but wishing thinking about a potential future possibility. Nothing different than 50 years of popular Science covers that have commercial space planes on the "horizon" for the last 40 years and other things that do not come to fruition. Must we go through each and every issue of that and say anything that did not make it, either became a secret black project cover-up and exists today, or merely that the the idea never had enough financial backing and the technological limits at the time were a little to be to be profitable?

Thanks for your post and your opinion IgnoreTheFacts. Although I think your grammer, adjectives and vocabulary are not college level neither are mine sometimes.

Thanks again.

Most of the time i probably have you both beat. my grammar for typing really sux...

[edit on 17-9-2007 by DIRTMASTER]

Originally posted by JustMike

Originally posted by DIRTMASTER

I hope Mr Lear will not mind me commenting on this, but as he said, it's "boundary layer control", not "layer control". I don't read Mr Lear's statement to imply that it is a method of propulsion in and of itself. It isn't.
To explain, "boundary layer" is simply a term used in fluid dynamics (air and water both being fluids, if you will), and it refers to the region (or layer) proximal to contact between a fluid and a surface. One of the problems that has bedevilled humankind since we first started constructing boats (and later aircraft and subs) is the turbulence that is created in this layer where the surface of a craft and the fluid interact.
"Streamlining" is a simplified concept of "boundary layer control", where efforts are made to allow the object to pass through the fluid with the lowest amount of turbulence and coefficient of friction. This has been an especially tough nut to crack in terms of subs because not only does the entire vessel spend much of its time submerged but also needs to function with reasonable stability and maneuverability when on the surface (and so only partially submerged), it is also beneficial for the sub to be able to obtain a high rate of knots when underwater in relation to its mass and the power it has available for propulsion.
After a huge amount of research, various types of improvements have been made to controlling the interaction in this boundary layer, all of which give the vessel significantly higher top speeds per unit of power input into the system and (very importantly) generate less sound.
If you search "boundary layer control" as a phrase with "submarine" you will find some very interesting documents. The ones that relate to electromagnetic and electrostatic boundary layer control systems are especially worth a look.

In regards to propulsion, it is true that older-generation methods (screws) are very inefficient; though not a lot is floating around on the web that is verifiable, it seems that vastly better boundary layer control -based propulsion systems are either in use or being tested.



In this case, the problem was not building such propulsion units. It was making them work (by pushing water backwards relative to direction you want the sub to go) in such a way that turbulence did not negate the advantages of thrust they produce, or did not produce sound that could be identified as a "fingerprint" of the vessel.

Mike

OK now i know exactly what your talking about. I figured i wasn't on the same page

Electromagnetic.. they have been trying to put that on an ssn for decades. One Russian boat in particular and was the inspiration for the movie hunt for red October. the real boats name was simply October. the reason it didn't work was that the Russians didn't at that time know that we weren't tracking them on the same noise system they used. we primarily use narrow band frequencies off say the 50hz electrical bus. there are many magic frequencies. the issue was the electro magnetics made it functionally silent but electromagnetically... noisy as hell. their actually is a process to reduce the magnetic field on your way out to sea for that reason.

when a normal sonarman today says the word layer..we usually are referring to the "sonic layer"or"scattering layer" of biologics and algae that sit at about 70 to a 100 feet. riding just below them you can hide from many surface sonars.
on reason we are not currently {on an ssn} using that to do as many would suggest and polarize the hull and do some water slipstreaming..even if it didnt show us to the whole world on narrowband. is the pumps would have to run on high speed. being mechanically noisy. the german torpedo that exploded on the kursk was that type of prop.{electro induction to reverse the water as you mentioned} at 100kts published speed silence no matter thats why its on the torpedo and others..

[edit on 17-9-2007 by DIRTMASTER]

In this case, the problem was not building such propulsion units. It was making them work (by pushing water backwards relative to direction you want the sub to go) in such a way that turbulence did not negate the advantages of thrust they produce, or did not produce sound that could be identified as a "fingerprint" of the vessel.
"Streamlining" is a simplified concept of "boundary layer control", where efforts are made to allow the object to pass through the fluid with the lowest amount of turbulence and coefficient of friction.- Mike



mike you are exact on the "fingerprint" that is a pattern of narrow band signals that overtime can expose a specific boat or type.. the friction in boat speak is just"flow noise"and "transient" i think we are on the same page pretty much. just different common terms.

I do have an idea that I wanted to throw at y'all about the propulsion flaws they may be working on..

a composite or experimental non-metal hull{instead of hy80 or 85} that could... contain the electro magnetics inside the hull. the way you contain for the reactor.. redesign the plant to run as a hybrid to put higher electrical loads on the natural circulation{no pumps running}...I believe such a boat could be made but would be a complete departure from everything we have previously built. hopefully the nonmetal hull wouldn't disintegrate the way some of the titanium Russian hulls did..

is this the type of thing that john is suggesting?



[edit on 17-9-2007 by DIRTMASTER]

[edit on 17-9-2007 by DIRTMASTER]

Originally posted by JustMike

I hope Mr Lear will not mind me commenting on this, but as he said, it's "boundary layer control", not "layer control". I don't read Mr Lear's statement to imply that it is a method of propulsion in and of itself. It isn't.

Mind? Mind? You just stole all my stuff and you think I am going to mind?

Great post JustMike! You saved me a lot of typing and not only that you put it better than I could have.

Thanks again JustMike.

Originally posted by johnlear
Originally posted by JustMike

I hope Mr Lear will not mind me commenting on this, but as he said, it's "boundary layer control", not "layer control". I don't read Mr Lear's statement to imply that it is a method of propulsion in and of itself. It isn't.

Mind? Mind? You just stole all my stuff and you think I am going to mind?

Great post JustMike! You saved me a lot of typing and not only that you put it better than I could have.

Thanks again JustMike.

John... are you holding back on the composite/hybrid? I would love to read anything similar you've got. Really!

Originally posted by schuyler

Re: the CVNs' top speed being in the 70 knot category I've heard this for over 40 years, first from an ex CPO who declared the top speed of the Enterprise was 70 knots. Yet this causes difficulty with the law of thermodynamics. To go that fast the carrier would have to on top of the water like a hydroplane. What a wild ride that would be! But performance is subject to hyperbole and wishes that it were so.

Thanks for the post schuyler. As you know HS is 1.34 times the square root of the waterline for a displacement hull. So ballpark HS for the Ronald Reagan would be 42 knots.

There are several disciplines to mitigate this limitation: one is power, another is electrostatic/magnetic energy (boundary layer control), another is reduction in coefficient of friction for the hull below the waterline sometimes referred to as composite/hybrid. I don't know how far advanced WIG is with displacement hulls (as outrageous a concept as that may seem). I imagine they have done some research in that area.

Enterprise had early composite/hybrid technology.

As far as top speed figures go, there a 2. One is called ‘classified speed’ which you can find out if you have the right clearance and one is ‘secret speed’ the real top speed. The Enterprise’s secret speed is 70 knots as you said. I would imagine that the Ronald Reagan, is well over 85 knots using advanced technology of portions of all those disciplines. But thats just a guess. With the technology that the U.S. Navy has it might be 100kts.

Those new nuclear (probably fusion) subs that the seal teams use (the 40 ft. long ones) go at least 100 kts. and probably much faster.

But no. The Ronald Reagan would not have to hydroplane to obtain 65 knots.

Thanks for the post.

All of the above is my opinion.

Originally posted by johnlear
Originally posted by schuyler




Thanks for the post schuyler. As you know HS is 1.34 times the square root of the waterline for a displacement hull. So ballpark HS for the Ronald Reagan would be 42 knots.

There are several disciplines to mitigate this limitation: one is power, another is electrostatic/magnetic energy (boundary layer control), another is reduction in coefficient of friction for the hull below the waterline sometimes referred to as composite/hybrid. I don't know how far advanced WIG is with displacement hulls (as outrageous a concept as that may seem). I imagine they have done some research in that area.

Enterprise had early composite/hybrid technology.

As far as top speed figures go, there a 2. One is called ‘classified speed’ which you can find out if you have the right clearance and one is ‘secret speed’ the real top speed. The Enterprise’s secret speed is 70 knots as you said. I would imagine that the Ronald Reagan, is well over 85 knots using advanced technology of portions of all those disciplines. But thats just a guess. With the technology that the U.S. Navy has it might be 100kts.

Those new nuclear (probably fusion) subs that the seal teams use (the 40 ft. long ones) go at least 100 kts. and probably much faster.

But no. The Ronald Reagan would not have to hydroplane to obtain 65 knots.

Thanks for the post.

All of the above is my opinion.

hmmm. flank speed = secret speed. flank on the Ohio always made the entire hull wiggle..

I had always heard the Enterprise could do" donuts" and obscure things. A unique propulsion explains a lot. 5 reactors.. for what? ..you would never put that much energy on a screw. the extra reactor could be for the hybrid propulsion..?!
Am i close?