Navy Railgun Tests Leading to Ship Superweapon by 2020 - Page 4




+ Log in or register to post
Page 4 of 10 FirstFirst 1 2 3 4 5 6 7 8 9 10 LastLast
Results 31 to 40 of 98
  1. #31
    Registered User
    Enchanter (Lvl 12)

    Jack7's Avatar

    Join Date
    Aug 2007
    Location
    Greenville, SC
    Posts
    1,988
    Blog Entries
    40

    Ignore Jack7
    It's a high acceleration kinetic weapon. In addition to all of the other forces being employed to project the weapon and traveling with the warhead, the projectile is dragging gravity and the accumulated g-forces with the projectile. Nothing solid wants to get hit by that because it will re-transfer those same g-forces to the target.

    In addition to all of the other kinetic and physical forces.

 

  • #32
    Quote Originally Posted by Dannyalcatraz View Post
    A railgun version of grapeshot could be hideous, for instance.
    A warship mounted shotgun... why am I imagining Cthulhu & Gojira having a Rabbit Season / Duck Season argument?

  • #33
    Community Supporter COPPER SUBSCRIBER
    Grandfather of Assassins (Lvl 19)

    jonesy's Avatar

    Join Date
    Feb 2003
    Location
    Helsinki, Finland
    Posts
    4,838
    Pathfinder Dragonlance

    Ignore jonesy
    Quote Originally Posted by Nagol View Post
    1) Rail guns require long "barrels" for acceleration so plane mounts would be problematic.

    2) The recoil would knock the plane below stall speed I expect.
    But, it's a railgun. Magnetically accelerated. I thought those things didn't have any recoil?

    My sarcasm detector is fusion powered. Yeah, that's powerful enough.

    You are what you do.

    Dragonlance.com Forums - The Dragonlance Lexicon - The Kencyclopedia

  • #34
    I'm no scientist, and I'm just guessing but while the mechanism might not generate traditional recoil, the projectile leaving the gun at such high velocities might make some sort of physical interference.

  • #35
    Mod Squad
    A 1e title so awesome it's not in the book (Lvl 21)

    Umbran's Avatar

    Join Date
    Jan 2002
    Location
    Boston, MA
    Posts
    25,949
    Blog Entries
    6

    Ignore Umbran
    Quote Originally Posted by jonesy View Post
    But, it's a railgun. Magnetically accelerated. I thought those things didn't have any recoil?
    Newton's Third Law still applies. For every action, there is an equal and opposite reaction. A force is applied to the projectile, so a force in the other direction is applied to the launcher. That electromagnetism is used to apply forces to the object does not change that most basic of facts.

    So, there will be recoil.

    Quote Originally Posted by Jack7 View Post
    In addition to all of the other forces being employed to project the weapon and traveling with the warhead, the projectile is dragging gravity and the accumulated g-forces with the projectile.
    The thing only weighs 40 pounds, and while it is moving at high mach numbers, it is not moving at relativistic speeds. This thing will have no noticeable gravitational effects.

    You don't want to get hit by it, because it has a lot of kinetic energy and momentum, and if it hits you it will transfer some of those to you in a very short time, and that will hurt.

  • #36
    Community Supporter COPPER SUBSCRIBER
    Grandfather of Assassins (Lvl 19)

    jonesy's Avatar

    Join Date
    Feb 2003
    Location
    Helsinki, Finland
    Posts
    4,838
    Pathfinder Dragonlance

    Ignore jonesy
    Quote Originally Posted by Umbran View Post
    Newton's Third Law still applies. For every action, there is an equal and opposite reaction. A force is applied to the projectile, so a force in the other direction is applied to the launcher. That electromagnetism is used to apply forces to the object does not change that most basic of facts.

    So, there will be recoil.
    That doesn't directly translate to recoil. Equal and opposite reaction as a concept is misleading in some cases. A bazooka has practically no recoil at all in comparison to with how much power it unleashed its projectile with, and yet equal and opposite reaction fully applies. There are guns which are designed to dissipate the 'opposite' force so that when you fire them the accuracy isn't affected, because the 'recoil' isn't all in the backwards direction. They call it recoil reduction.

    Equal and opposite when talking of amounts of power unleashed, sure. But the direction of the reaction isn't always directionally opposite.

    So, when I think railgun, I think it should be possible to design one the way they design wingtip missile launchers which have about as much recoil as a bazooka. Even more so since the projectile isn't 'touching' the tube it's launched from when it's launched. Right?

    Edit:
    And when I say 'the way they design wingtip missile launchers' I mean positionally, not mechanically. Obviously.
    Last edited by jonesy; Friday, 2nd March, 2012 at 12:00 AM.

    My sarcasm detector is fusion powered. Yeah, that's powerful enough.

    You are what you do.

    Dragonlance.com Forums - The Dragonlance Lexicon - The Kencyclopedia

  • #37
    Registered User
    Grandfather of Assassins (Lvl 19)



    Join Date
    Jan 2008
    Posts
    5,009
    Circvs Maximvs Forgotten Realms D&D

    Ignore El Mahdi
    Quote Originally Posted by Thunderfoot View Post
    If I'm reading the technology right, basically this is a very high powered catapult, meaning it's fire and forget, straight line trajectory so anti-aircraft and missile defense uses are neigh unto impossible as there would be no way to "direct" the round or have it home like radar, sonor, laser, video and fly by wire munitions.
    From the article:

    U.S. Navy commanders ultimately want a weapon capable of firing up to 10 guided projectiles per minute at targets up to 100 miles away.
    Not aimed projectiles, guided projectiles. The only propulsion they would have would be that which they get from the initial firing. But they can still be guided projectiles in much the same way we have guided gravity bombs. They could use camera, radar, laser targeting, ground mapping with inertial nav, GPS, or a combination of these for guidance (like Boeing's JDAM package).

    Railgun projectiles could look something like this:




    For comparison, a MK-84 JDAM. A 2000lb guided gravity bomb with GPS/Inertial Nav and Laser Targeting.



    Quote Originally Posted by Umbran View Post
    Punching through the side of the target is just fine. Having penetrated, your metal slug is now fracturing, rolling, tumbling and ricocheting around inside a big metal or concrete box. Mayhem ensues.
    Yup! In mechanical and military parlance, we call it "spalling".


    Quote Originally Posted by jonesy View Post
    That doesn't directly translate to recoil. Equal and opposite reaction as a concept is misleading in some cases. A bazooka has practically no recoil at all in comparison to with how much power it unleashed its projectile with, and yet equal and opposite reaction fully applies. There are guns which are designed to dissipate the 'opposite' force so that when you fire them the accuracy isn't affected, because the 'recoil' isn't all in the backwards direction. They call it recoil reduction.
    Well, a bazooka has very little recoil because 1) the propelling force is internal to the projectile (unlike the rail gun); and 2) the rear of the launch tube is open, so the force of the rocket engine does not directly interact with the launch tube - if the back of the tube was closed, then the person holding the weapon would experience the full recoil of the rocket (which would be extreme to say the least, at least until the launch tube exploded...)

    With the rail-gun, the force to propel the projectile is coming from the rails affixed to the inside if the weapon. Picture it this way, in much the same manner as a balloon squeezes out the air inside it (though equalization of pressure is also involved), and thus propels itself in an opposite direction - the magnetic fields of the rails are squeezing out the electfrified projectile (which now has it's own magnetic field), while much like the balloon, the weapon itself is propelled in the opposite direction (except that the gun is affixed and has mechanisms to disipate the recoil).


  • #38
    Community Supporter COPPER SUBSCRIBER
    Grandfather of Assassins (Lvl 19)

    jonesy's Avatar

    Join Date
    Feb 2003
    Location
    Helsinki, Finland
    Posts
    4,838
    Pathfinder Dragonlance

    Ignore jonesy
    Quote Originally Posted by El Mahdi View Post
    With the rail-gun, the force to propel the projectile is coming from the rails affixed to the inside if the weapon. Picture it this way, in much the same manner as a balloon squeezes out the air inside it (though equalization of pressure is also involved), and thus propels itself in an opposite direction - the magnetic fields of the rails are squeezing out the electfrified projectile (which now has it's own magnetic field), while much like the balloon, the weapon itself is propelled in the opposite direction (except that the gun is affixed and has mechanisms to disipate the recoil).
    I can always get behind a good balloon analogy.

    My sarcasm detector is fusion powered. Yeah, that's powerful enough.

    You are what you do.

    Dragonlance.com Forums - The Dragonlance Lexicon - The Kencyclopedia

  • #39
    Registered User
    Enchanter (Lvl 12)

    Jack7's Avatar

    Join Date
    Aug 2007
    Location
    Greenville, SC
    Posts
    1,988
    Blog Entries
    40

    Ignore Jack7
    The thing only weighs 40 pounds, and while it is moving at high mach numbers, it is not moving at relativistic speeds. This thing will have no noticeable gravitational effects.

    You don't want to get hit by it, because it has a lot of kinetic energy and momentum, and if it hits you it will transfer some of those to you in a very short time, and that will hurt.
    No, I'm not talking about relativistic speeds obviously. I'm talking about how g-forces build in the warhead projectile which will be concentrated, along with all other relevant forces against a very small area.

    I'm talking about the g-forces, along with all of the other forces, that are generated by an object at high acceleration (within a gravitational field) stopped suddenly by impact against solid surfaces. Though it won't be stopped by the solid surfaces it will targeted against. But all of those energies will be concentrated in a very small impact area, though exactly how those forces are transferred to the target will vary by the actual nature of the target (and the warhead).

    But I'm not talking about planetary g-forces, I'm talking about the g-forces generated by small but massive objects accelerating at high speeds and impacting other objects at tight impact points. Again though, that's just one of the forces that will actually be involved.

    And of course much will depend upon the shape and nature of the matter of the target and the shape and matter of the projectile.

  • #40
    Member
    The Great Druid (Lvl 17)

    Kzach's Avatar

    Join Date
    Oct 2007
    Location
    Ringwood
    Posts
    4,232

    Ignore Kzach
    There's a blatantly obvious application that you're all overlooking here and so I feel bears pointing out: space-guns!

    We're one-step closer to ruling the galaxy, humans!

  • + Log in or register to post
    Page 4 of 10 FirstFirst 1 2 3 4 5 6 7 8 9 10 LastLast

    Similar Threads

    1. Not exactly Cyberpunk 2020
      By Wolf1066 in forum RPGs & Tabletop Gaming Discussion
      Replies: 31
      Last Post: Sunday, 13th June, 2010, 11:41 PM
    2. Ship-to-ship fighting & dousing fire
      By MarauderX in forum D&D and Pathfinder
      Replies: 7
      Last Post: Monday, 6th April, 2009, 01:53 PM
    3. rules for ship-to-ship combat and PC's as crew
      By GlassJaw in forum RPGs & Tabletop Gaming Discussion
      Replies: 12
      Last Post: Friday, 29th June, 2007, 02:03 AM
    4. What do you use for naval combat/ship-to-ship action?
      By The_Universe in forum RPGs & Tabletop Gaming Discussion
      Replies: 21
      Last Post: Monday, 2nd October, 2006, 07:38 PM
    5. Ship to Ship Hits & Crits (Paging FRANCISCA)
      By Rel in forum RPGs & Tabletop Gaming Discussion
      Replies: 27
      Last Post: Tuesday, 29th August, 2006, 06:41 PM

    Posting Permissions

    • You may not post new threads
    • You may not post replies
    • You may not post attachments
    • You may not edit your posts
    •