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Thread: Virginia Submarine

  1. #21
    Quote Originally Posted by etc_ss View Post
    There are good sources of information out there, but I would shy away from 'wikipedia'. I would lean towards Jane's Fighting Ships for this type of data...the book is expensive ( roughly $1000 ), but it's a good source that is constantly updated.
    A much more affordable resource is Combat Fleet of the World and Guide to World Naval Weapon Systems from the USNI although it only comes out every 5+ years. Worth becoming a member just for the discount on that alone.
    Last edited by Wiz33; 27-04-2012 at 22:33.

  2. #22
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    Quote Originally Posted by claudiucojo View Post
    Virginia is newer than the Seawolf and has some newer technologies, is true that it was meant to be 20% cheaper but not because it has degraded combat abilities, on the contrary it can do all that the Seawolf does and more(because of littoral water capability). It has a lower weapon payload(40 vs 50 and 4 torpedo tubes + 12 VLS(2x6 in Block III) vs 8 torpedo tubes) but it should still be enough to handle any conceivable thread out there.

    Virginia is cheaper because it was the first sub designed in CAD which reduced the design time dramatically and also potential problems with designers not knowing what the others were doing and creating problems when everyone tried to put everything together in the same place.

    They have a modular design where modules can be fabricated anywhere and just plunged in, there is no need to redesign a hole part of the sub to facilitate some changes.

    They are also splitting the sub construction between GD Electric Boat and Newport News Shipbuilding which reduced the cost from 2.4 bil -> 2.0 bil dollars.

    The Virginia class is far the chippest, jack of all trades sub that some are portraying. It's just that manufacturing and design technology has come a long way since the time the Seawolf was created.

    I don't thing that the Virginia is in any way less capable than the Seawolf class, it's just that it was designed to do what the Seawolf does and more.
    Newer technologies? Both use the same combat system (BYG-1), SONAR system (BQQ-10), ESM system (BLQ-10), and RADAR (BPS-16). Virginia is fly by wire vice traditional hydraulics for control surfaces, but that doesn't change ship handling drastically. The US Navy has gone to great lengths to put the same level of technology on all platforms, so all SSNs have BYG-1/BQQ-10 and are being fitted with the BLQ-10. The 21 class has the advantage of having more inboard living space (which makes working on them much easier).

    12 VLS, 24 Torpedoes in the room assuming all stows are loaded...to get to 40 you would have to load all tubes as well. Boats don't do that...they couldn't index weapons if the room was full and all tubes were full. The Seawolf has an automated torpedo room, you touch a screen and tell the system what weapon goes where, and the room starts to move. Virginia does not...she is more manual and that was done to allow her torpedo room to be 'reconfigurable', so the edge goes to the Seawolf.

    If I had a choice between the two, I would go to sea on a 21 class over a 774 every day. 774 was not designed with speed in mind. She IS slower and was designed to be. The only advantage the 774 has is the SOF lockout chamber which allows for delivery of special forces.

    The "SS" in my title denotes Submarine Warfare Qualified...

  3. #23
    NVM: i was going to say that the seawolf was powered by a pumpjet but the Virginia is too.


    And etc, im sorry to say but this aint Sonalysts making Dangerous Waters or Jane's. They dont have access to the same resources.

    And the very nature of the Seawolf was it was designed to be the be all end all of submarines, the F-22 of subs. It was designed to be FAR better then anything the soviets had, to blow the akula and alfa and all of those out of the water. It was horribly expensive, but also vastly innovative and advanced. Of course, the end of the cold war mean the american tax payer simply didnt want to pay anymore, and it really isint needed in the 21st century (until russia builds up or LOL china)
    Last edited by Guynumber7; 29-04-2012 at 10:45.

  4. #24
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    Quote Originally Posted by etc_ss View Post
    Newer technologies? Both use the same combat system (BYG-1), SONAR system (BQQ-10), ESM system (BLQ-10), and RADAR (BPS-16). Virginia is fly by wire vice traditional hydraulics for control surfaces, but that doesn't change ship handling drastically. The US Navy has gone to great lengths to put the same level of technology on all platforms, so all SSNs have BYG-1/BQQ-10 and are being fitted with the BLQ-10. The 21 class has the advantage of having more inboard living space (which makes working on them much easier).

    12 VLS, 24 Torpedoes in the room assuming all stows are loaded...to get to 40 you would have to load all tubes as well. Boats don't do that...they couldn't index weapons if the room was full and all tubes were full. The Seawolf has an automated torpedo room, you touch a screen and tell the system what weapon goes where, and the room starts to move. Virginia does not...she is more manual and that was done to allow her torpedo room to be 'reconfigurable', so the edge goes to the Seawolf.

    If I had a choice between the two, I would go to sea on a 21 class over a 774 every day. 774 was not designed with speed in mind. She IS slower and was designed to be. The only advantage the 774 has is the SOF lockout chamber which allows for delivery of special forces.

    The "SS" in my title denotes Submarine Warfare Qualified...
    Can you provide some sources to back up your claims(that Virginia was not designed with speed in mind and the automatic torpedo room) ?

    Its all nice and great that you decided to share this info but I would be happier with some hard data to support your info.

  5. #25
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    Would also be interesting to explain us exactly what not design with speed in mind means(you mean to imply that the Virginia class, the class that will power the US NAVY in the next half a century of submarine warfare, was designed to be slow ???).

    Not a great design decision in that case.

  6. #26
    Quote Originally Posted by claudiucojo View Post
    Can you provide some sources to back up your claims(that Virginia was not designed with speed in mind and the automatic torpedo room) ?

    Its all nice and great that you decided to share this info but I would be happier with some hard data to support your info.
    I think he was implying that he works on submarines, and has easier access to information.

    As for things being designed to be slow, I think it might be better phrased to say "not as fast". If there is no requirement for ultra-high speeds, then the engineering required to make that a component in the design can be saved and either used as cost savings or towards something else. And it's not unheard of. The Los Angeles subs, for instance, did not dive as deep as the earlier Permits because it was not believed to be as important as speed at the time. As the world environment changes, (projected threats, availability of other systems, budget outlook, to name just a few) these emphases change.

  7. #27
    Yep. I take his "not build for speed" as not going to be faster than a Seawolf.

  8. #28
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    I think only the US Navy and a couple of people really know the true speed of the Seawolf or Virginia, but I think we can safely assume that the Virginia class can do 35 knots, I did not say its faster than the Seawolf but I don't think is far away(the ratio hp/kg is roughly equal if you compare the data from known sources).

  9. #29
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    Quote Originally Posted by claudiucojo View Post
    I think only the US Navy and a couple of people really know the true speed of the Seawolf or Virginia, but I think we can safely assume that the Virginia class can do 35 knots, I did not say its faster than the Seawolf but I don't think is far away(the ratio hp/kg is roughly equal if you compare the data from known sources).
    Doubtful, I would be very surprised if the "Virginia" class can sustain a submerged speed of 35 knots.

    As Etc pointed out, the powerplant of the Virginia class is designed for longevity and reliability, not absolute max speed.

    Besides, you really have to define what you mean as max speed:

    A - the max speed the boat can hit for a few minutes in trials when all excess weight has been removed?; or

    B - the max speed the boat can safely hit for several hours or days as it transits from one area to another.

    In NWAC, only the B max speed is really pertinent.

  10. #30
    Speed of U.S. Warship have always been very conservative on all publish source but there have been consistent report that they are actually much faster than that. CVN have been observed doing close to 40 knots and the same have been said about all the SSN.

  11. #31
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    Quote Originally Posted by captain Queeg View Post
    Doubtful, I would be very surprised if the "Virginia" class can sustain a submerged speed of 35 knots.

    As Etc pointed out, the powerplant of the Virginia class is designed for longevity and reliability, not absolute max speed.

    Besides, you really have to define what you mean as max speed:

    A - the max speed the boat can hit for a few minutes in trials when all excess weight has been removed?; or

    B - the max speed the boat can safely hit for several hours or days as it transits from one area to another.

    In NWAC, only the B max speed is really pertinent.
    If Los Angeles can do 35 knots I think Virginia could do better, and yes I think that 35 knots sustained should be right on the money for the Virginia with burst speed > 35 knots.

    Regarding the reactor, I don't think its relevant if its designed for longevity, they way you use it is more important, the reactor can be used at max and even over 100% probably 110-115% if needed.

  12. #32
    Quote Originally Posted by captain Queeg View Post
    Doubtful, I would be very surprised if the "Virginia" class can sustain a submerged speed of 35 knots.

    As Etc pointed out, the powerplant of the Virginia class is designed for longevity and reliability, not absolute max speed.

    Besides, you really have to define what you mean as max speed:

    A - the max speed the boat can hit for a few minutes in trials when all excess weight has been removed?; or

    B - the max speed the boat can safely hit for several hours or days as it transits from one area to another.

    In NWAC, only the B max speed is really pertinent.
    Why would B be that pertinent? Subs should be running slow most of the time. Top speed is mostly important for evasive maneuvers so a burst of extra speed can mean the difference between a torpedo hit and a near miss and therefore very important. Same goes if detected by active sonubuoy. You have been pinged so you go loud and try to change position as quick as possible before the helo gets on top of you to drop a torp. With a bit of speed you could hope out of sonar range and go back to running silent if you manage to find the edge of the buoy drop pattern.

  13. #33
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    Quote Originally Posted by claudiucojo View Post
    If Los Angeles can do 35 knots I think Virginia could do better, and yes I think that 35 knots sustained should be right on the money for the Virginia with burst speed > 35 knots.
    Top speed is classified so no one knows how fast a LA sub can go in RL. All the numbers being thrown about in forums are just rumours or guesses. However, if you extrapolate from known numbers: known top speed of November, Sturgeon, Thresher classes, design objectives of L.A./Seawolf/Virginia classes, known speed/power formulas for subs, the most likely max speed for the LA/Seawolf/Virginia class is in the 30-35 Kts range with the LA/Virginia most likely at the lower range and the Seawolf at the upper range.

    Regarding the reactor, I don't think its relevant if its designed for longevity, they way you use it is more important, the reactor can be used at max and even over 100% probably 110-115% if needed.
    A nuclear reactor can't develop more than 100% of its max power. You can push a powerplant to 100%, if you are willing to risk blowing parts of the system and having the sub dead in the water.

    Remember, speed if a function of power. To double your speed, you have to increase your power by a factor of 4, so going from 30 to 35 knots requires a very large increase of power.

  14. #34
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    Quote Originally Posted by Ours View Post
    Why would B be that pertinent? Subs should be running slow most of the time. Top speed is mostly important for evasive maneuvers so a burst of extra speed can mean the difference between a torpedo hit and a near miss and therefore very important. Same goes if detected by active sonubuoy. You have been pinged so you go loud and try to change position as quick as possible before the helo gets on top of you to drop a torp. With a bit of speed you could hope out of sonar range and go back to running silent if you manage to find the edge of the buoy drop pattern.
    Not really, top speed is most useful operationally when moving from one area to another or when tracking a high speed target, for example when tracking fast Soviet subs during the Cold War, US SSNs would often alternate: slow down to acquire the target and plot its course, do a high speed run for a certain period to a plotted intercept course, slow down again to reacquire the target, etc.

    Going to max speed to evade a torpedo or escort is seldom the right move. Max speed makes the sub noisy and easier to track/target and no matter how fast it goes, the sub can't outrun a torpedo or Helo/Air ASW platform. It usually makes more sense to stay at silent speed and make it as hard as possible to be tracked.

  15. #35
    Going flank speed does work against a torpedo. It it's dropped far enough the sub doesn't needs to outrun the torpedo. It just needs to make the torpedo run until it hits its maximum range. But running full speed at the opposite direction of the torpedo's travel, it increases the distance the torpedo needs to travel to its target. As subs are slower than torpedoes this is not always possible but the further the torpedo is launched, the easier it is to maneuver beyond his maximum range.

    Plus subs use active countermeasures so if those work its better to get away as fast as possible to prevent re-acquisition. It's also good to move fast in order to increase the area the enemy has to search for you.

    I'll remind you this is all once the sub has been detected or even worse fire upon. Silent running goes out the window until you our no longer targeted and out of active sonar range. You can be quiet as a hole in the water but it would help much against an active sonar tracking torp.

  16. #36
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    Quote Originally Posted by captain Queeg View Post
    Top speed is classified so no one knows how fast a LA sub can go in RL. All the numbers being thrown about in forums are just rumours or guesses. However, if you extrapolate from known numbers: known top speed of November, Sturgeon, Thresher classes, design objectives of L.A./Seawolf/Virginia classes, known speed/power formulas for subs, the most likely max speed for the LA/Seawolf/Virginia class is in the 30-35 Kts range with the LA/Virginia most likely at the lower range and the Seawolf at the upper range.



    A nuclear reactor can't develop more than 100% of its max power. You can push a powerplant to 100%, if you are willing to risk blowing parts of the system and having the sub dead in the water.

    Remember, speed if a function of power. To double your speed, you have to increase your power by a factor of 4, so going from 30 to 35 knots requires a very large increase of power.
    Please read this article: http://edition.cnn.com/2005/US/01/10...marine.update/

    The submarine was traveling in excess of 33 knots when its nose hit the undersea formation head-on, officials said.

    This is the Los Angeles, a 30 year old boat going > 33 knots and your telling me that a new state of the art Virginia cannot do 35 knots ? I find that hard to believe but maybe you are right, I'm not saying that it can do just that all the evidence point that it can hit 35 knots.

    Regarding the reactor over 100% I was under the impression that 100% is max safe operating output but for short periods you can go over 100%, I saw this in the movie The Hunt For the Red October for example but maybe its not true.

  17. #37
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    Quote Originally Posted by claudiucojo View Post

    They have a modular design where modules can be fabricated anywhere and just plunged in, there is no need to redesign a hole part of the sub to facilitate some changes.
    Partly true. This applies to things like electronics cabinets. The real key to reducing construction time and costs was designing major sections of the submarine as very large modules, so that they could be assembled, outfitted, and in some cases completely tested, in the "shop" and then loaded into the hull sections. This is a large reduction in construction cost over previous designs where modular construction techniques were used but the design was divided up after the design was complete in an attempt to make it modular, rather than designing it that way up front.

    They are also splitting the sub construction between GD Electric Boat and Newport News Shipbuilding which reduced the cost from 2.4 bil -> 2.0 bil dollars.
    No. Building at one shipyard would be less expensive. The decision to split the build was a combination of politics and maintaining the industrial base. The construction was split from the start with VIRGINIA. The exact split of tasks has changed over the class but not too much. The $400M reduction was a combination of an extensive cost reduction effort by the whole team and the Navy now contracting for larger numbers of ships at once, so that the two shipyards could order long lead material in greater quantities at better prices. Large numbers of design changes were made to reduce construction costs while keeping capability the same (or even enhanced).

    Any on-line numbers on speed and depth are only educated guesses. SEAWOLF was designed to be the most capable attack submarine ever, in every specification, and it's real fast - designed to be. At the height of the Cold War, cost wasn't an object (not much anyway). The Soviet Union fell apart, missions changed, and VIRGINIA resulted, as a way to get the best submarine possible within certain parameters, including being affordable.
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  18. #38
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    Quote Originally Posted by claudiucojo View Post
    Please read this article: http://edition.cnn.com/2005/US/01/10...marine.update/

    The submarine was traveling in excess of 33 knots when its nose hit the undersea formation head-on, officials said.

    This is the Los Angeles, a 30 year old boat going > 33 knots and your telling me that a new state of the art Virginia cannot do 35 knots ? I find that hard to believe but maybe you are right, I'm not saying that it can do just that all the evidence point that it can hit 35 knots.

    Regarding the reactor over 100% I was under the impression that 100% is max safe operating output but for short periods you can go over 100%, I saw this in the movie The Hunt For the Red October for example but maybe its not true.
    On the article, most of the articles only said the sub was going at flank speed. The Navy has always kept the top speed of these subs confidential, as you know they only admit to 25+ officially. I would have been surprised the Navy officially confirmed they could do 33+. Most likely the journalist was just guessing. If we could find the official Navy press release confirming 33+ kts, that would be different of course.

  19. #39
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    Quote Originally Posted by Ours View Post
    Going flank speed does work against a torpedo. It it's dropped far enough the sub doesn't needs to outrun the torpedo. It just needs to make the torpedo run until it hits its maximum range. But running full speed at the opposite direction of the torpedo's travel, it increases the distance the torpedo needs to travel to its target. As subs are slower than torpedoes this is not always possible but the further the torpedo is launched, the easier it is to maneuver beyond his maximum range.

    Plus subs use active countermeasures so if those work its better to get away as fast as possible to prevent re-acquisition. It's also good to move fast in order to increase the area the enemy has to search for you.

    I'll remind you this is all once the sub has been detected or even worse fire upon. Silent running goes out the window until you our no longer targeted and out of active sonar range. You can be quiet as a hole in the water but it would help much against an active sonar tracking torp.
    Yes, if a torp is launched at a very long range, it may be possible for a sub to outrun it by going to flank, but as soon as you go to flank, you announce your presence to every ASW unit in the area. It is then very simple to drop a pattern of weapons around the sub to kill it. Since the sub is now also totally deaf since it is running at flank, the job is even easier.

    The reality of modern ASW is that a sub which is detected is almost certainly dead which is why the name of the game is to stay as undetected as long as possible.

    If a torp is launched at long range, the ASW unit probably does not know exactly where the sub is or only suspects its presence. Going to flank only makes the ASW commander's job easier. A better tactic may be to set a course perpendicular to the torpedo track at silent speed, which may still be 15-20 kts, so you remain undetected and can still monitor the area. By the time the torpedo reaches your old position, you will hopefully be out of its acquisition cone.

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