How Do Rail Guns Work?




The electromagnetic rail gun is used by the United States Navy and it is very unique in that it is a gun that does not use gunpowder. Instead, it is powered by electricity and a magnetic field. It has been a huge technological advancement because before it was invented, the maximum range a gun could shoot a projectile was 12 miles. A rail gun can reach a target 250 miles away in 6 minutes, traveling at a speed of around 16,000 meters per second.




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The Basic Parts of a Rail Gun


A rail gun uses large amounts of power, so a power source has to be used that can generate millions of amps in order for a rail gun to function. The armature is the most important part of the rail gun because it is the metal piece (conductive sabot) that holds the projectile. On either side of the armature, there are two conductive rails which vary in length depending on the size and power capabilities of the rail gun. The rails are connected to the power source and the current from the source travels up one rail (the positive rail) and through the armature and back down to the power source through the other rail on the other side (the negative rail).


Simulation of How a Rail Gun Works

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How it Works

In the parts of the rail gun where an electric current is present, magnetic fields are present around rails. As shown in the diagram above, the magnetic field rotates in a counterclockwise direction around the positive rail. In the negative rail, the magnetic field rotates in a clockwise direction.

The main reason that a rail gun works is because of the third right hand rule. As illustrated in the diagram below, the magnetic field is always pointing outwards towards the sky and the current travels from the positive side to the negative side of the power source, which is to the right. This means that the force of the rail gun projects straight out of the gun. However, in order for a rail gun to work effectively and travel long distances at large speeds, there must be a great amount of force inflicted on the projectile. This is why millions of amperes are required in the power source for the rail gun to work properly.

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Due to the fact that a rail gun requires millions of amperes, the Navy does not have a solution for providing enough power to use a rail gun on a naval ship yet. However, they are currently working on building a type of battleship, the all-electric DD(X), which can temporarily take some power from the engine when

the rail gun needs to be used. Not only can rail guns be used in the military, but they can also be used to launch satellites or space shuttles into outer space potentially because a rail gun can have multiple projectiles, not just a missile.



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Rail Gun Test Video


Sources



http://science.howstuffworks.com/rail-gun.htm

http://www.powerlabs.org/railgun.htm

http://www.military.com/features/0,15240,160195,00.html