In World War 2 the largest battleships Could lob shells 30 miles or more. Missiles quickly replaced guns on Warships and today can travel for hundreds of miles before detonating at their target. Yet missiles can be prone To spoofing or jamming and can Potentially be intercepted and destroyed. Despite boasting some of the most advanced missiles in the world the US Military quickly realized that there were still some merits to good old-fashioned dumb projectiles but instead of looking back at the past U.S. Looked toward the future.

Even before the age of sail with its famous frigates and ships of the line full of cannons man has been putting long-range weapons aboard ships. Early naval vessels were often equipped with catapults or ballistic and their purpose was much the same as it remains today. Help soften up enemy coastal defenses or destroy other ships at sea.
Today's military warships, however, seem to have all but completely replaced traditional naval artillery but something completely new the long-range Anti-ship missile or land-attack Cruise Missile. While superior and every way to traditional cannons defensive technology has very quickly caught up and today's High-tech missiles are all too often at risk of being countered by enemy missile Defenses.

High-powered lasers can burn out a missile guidance system at a long-range, powerful jamming pod can interfere with the missiles targeting, electronic warfare suites can even hack into missile's active guidance and disrupt it and smaller more agile Missiles or high-speed Computer-controlled Chain guns can intercept them mid-flight. While a saturation strike involving Multiple missile volleys can overwhelm even the U.S.'s vaunted Aegis Missile Defense system. There still seems to be room for traditional artillery but it wasn't until recent technological development produced an alternative to modern missiles that was even remotely comparable. Even the big guns of World War II Arab battleships were too slow to fire and the projectiles lacked enough velocity to reliably strike their targets.
In battles of the era, the majority of attacks resulted in misses as even a slow-moving battleship dodging another battleships volleys can move out of the way of projectiles traveling at only a few hundred miles an hour If it was far enough away. It wasn't until ships closed into extremely close ranges that hits were guaranteed and that medium to long ranges battleships relied on radar and spotter planes to slowly train their guns onto a target. Faced with modern and much faster ships this is clearly not a viable alternative to missiles. Yet the development of the Electromagnetic railgun seemed to solve all of the follies of traditional Cannons by firing projectiles at incredible speeds upwards of 1.6 miles a second, far too fast to be easily dodged. But what exactly is a railgun?

In essence, a railgun is nothing more than a large Electrical circuit that uses magnetism to accelerate a projectile to greater speeds than possible by traditional gunpowder charges or even most missiles. The railgun consists of three parts:

A Power source
A pair of parallel rails
A moving armature

The power supply Generates current in the millions of Amps or enough to power a few thousand homes. The rails are long lengths of a highly conductive metal such as copper and could range from four to thirty feet ( 1 to 9 meters ) long.
The armature is a device that bridges the gap between the two rails and is typically a solid piece of conductive metal or a conductive sabot - a carrier that houses the projectile to be fired not unlike a sabot round fired from a traditional tank.

Some railguns, such as the American naval prototype use a plasma armature or a thin metal foil that is placed on the back of the non- conducting projectile. As the millions of Watts flow through the foil, it vaporizes and becomes plasma, which conducts the Current. To fire, the railgun discharges Power from the positive terminal of the Power supply and up the positive rail. The current then leaps across the Armature and down the negative rail and back to the Power supply.

As Michael Faraday taught us, a current flowing through a wire creates a magnetic field, which has both a magnitude and direction. The magnitude of this field indicates how powerful the Field is and the direction is the way the force lines of the magnetic field run. When the railgun is powered up and the current flows from one rail to the other the two rails act like wires with a magnetic field circulating around each rail. The force lines of the magnetic field run counterclockwise in the Positive rail and clockwise around the Negative rail, so the net magnetic field between the rails is directed vertically.
The projectile between the two rails acts like a charged wire in an electric field and experiences a force known as The Lorentz force - named after the Dutch physicist Hendrik A. Lorentz. Simply stated, the Lorentz Force the projectile experiences is a combination of the electric and magnetic force due to the two electromagnetic fields. Because of The alignment of the rails on either side of the projectile and the direction of the two magnetic fields, the Lorentz Force is thus directed perpendicular to both magnetic fields and to the direction of the current flowing across the armature.

The Lorentz force is also parallel to the two rails pushing the projectile away from the power supply and thus firing it like a cannon shell. Railgun projectiles are inert, meaning they have no explosive charge whatsoever. Instead, they rely on Isaac Newton's Second law of motion - Force equals Mass Times Acceleration.

Basically, the projectile is accelerated to incredible speeds, imparting it with extraordinary amounts of kinetic energy. When the projectile reaches its target and then imparts all that kinetic energy to its target with devastating results. In fact, rail guns could potentially outdo typical chemical warhead missiles and sheer destructive potential as traditional explosives are inherently limited in the amount of energy that can release by the energy potential of the materials used to create them.
A rail gun projectiles can have its kinetic energy and thus its destructive power increased by increasing the speed at which it is fired with the only limits being the ability to generate ever greater electrical currents and the projectile's resistance to disintegrating as it travels through the atmosphere. So if the railgun is so amazing and could potentially be even better than missiles in some scenarios, why isn't one operational yet?

The technical problems remain numerous up until recently the US Navy, in charge of developing the railgun for US ships, was having problems generating the power sufficient to continuously fire the railgun. Then as Power issues were sorted out and Wattages increased, the rails began to experience serious warping and melting as the Navy tried to reach the Pentagon's requirement that the railgun fire at a rate of 10 projectiles a minute, eventually only hitting 4.8 rounds a minute for fear of damaging the delicate rails. Yet technical problems can and have been largely overcome - the rail warping which may require further investment in material science to develop conductive materials capable of withstanding the incredible wattage coursing through it.
The real problem with the US's railgun is one familiar to many ambitious programs around the world - money. After ten years and 500 million dollars invested, the Pentagon began to grow dubious about the railgun's viability. Rather than further focus efforts on the railgun as a standalone weapon, large amounts of money were diverted to developing a hypervelocity projectile that used many of the same technological breakthroughs achieved with the railgun to instead make a new type of cannon Shell for the US Navy's 5-inch guns. With a speed of Mach 3 and a range of 30 Miles (48 km), the hypervelocity projectile will be a huge upgrade to U.S. Guns and easily make them the most powerful naval artillery in the world.

Yet critics of the Pentagon's decision to divert resources from pure railgun research point out (rightfully so) that a traditional powder projectile will never achieve the same performance as that offered by the railgun. While the railgun no doubt offers far greater benefits, the sad reality is that the Pentagon is currently extremely wary of big expensive weapons projects after spending billions on the F-35.

With Mark 45, 5-inch guns already installed on Every U.S. ship, the appeal of the hypervelocity projectile over a futuristic railgun is far greater. Currently, the future of the US's railgun is in serious question, and while most predict that a railgun will eventually be developed that may come far too late for the U.S. to maintain its technological advantage over its adversaries.
In fact, just this year China debuted what it claims to be a railgun on one of its frigates and said it was preparing for sea trials of the new weapon. While this has alarmed many in Washington, others are wary of the claims and suspicious that this is nothing more than a hoax meant to intimidate the US Navy, citing serious technological hurdles that are dubious China overcame so quickly. But if the Chinese railgun is real this wouldn't be the first time the US and its allies were surprised by a huge technological breakthrough by an underestimated rival.

In the last years of the Cold War, the Soviet Union's development of the Akula Class nuclear submarine surprised every Western observer who did not think the Russians would be capable of building such a sub for at least 10 more years.

More worrisome for Washington, if the Chinese have truly mastered a working Railgun and will follow through on their stated plans to install them on their Ships by 2025, it could signal the end of the U.S.'s absolute dominance of the Pacific Ocean and complicate the strategic picture for regional allies who fear China's South China Sea Aggression.