Ins and outs of railguns: Will they eventually see widespread usage?

Militaries around the world have been attempting to develop a functional, battlefield-ready railgun for over a century. Will it ever be pulled off?
Jex Exmundo
An electromagnetic railgun prototype aboard the USS Millinocket.Wikimedia Commons

Recently, the US Navy announced that it was pulling the plug on its planned railgun, sending 15 years of development and $500 million in R&D costs down the drain.

As per the Navy’s official statement, they intend to re-focus their R&D efforts towards the development of hypersonic missiles and directed energy weapons, as these weapon types are already seeing limited deployment around the world today. 

However, this might not be the only reason the Navy decided to move on from their planned railgun. Throughout development, the Navy struggled with making its railgun prototypes energy and resource-efficient. Firing a single shot from one of these prototypes involved diverting massive amounts of power from the ship it was stored on. 

The Navy’s railguns also suffered from another issue other railgun prototypes throughout history have gone through; poor reliability. Due to the sheer amounts of force generated with each shot, the barrels or rails of a railgun wore out incredibly fast, which made the gun less effective and less accurate over time without the constant replacement of its parts.

What is a railgun?

But what exactly is a railgun? To answer that question, we must first ask another: what would happen if someone built a really really big gun? 

And what if this gun was so big and so powerful that the sheer force of its projectile would be enough to sink even the sturdiest of ships? Well, you’d have an electromagnetic railgun.

Railguns have gone by many names in science fiction. They’ve been called mass drivers, magnetic accelerators, and notably in Doom, Gauss cannons. Regardless of what the writer calls it, it’s consistently been depicted as a projectile weapon that utilizes electromagnetic power to launch its projectiles at extremely high velocities.

How fast does a railgun shoot?

By design, railguns are intended to be among the most powerful projectile launchers in the world. An electromagnetic railgun is designed to launch projectiles towards their target at velocities several orders of magnitude faster than the speed of sound.

To illustrate, the US Navy’s prototype railgun was able to launch its projectiles at Mach 6 - six times faster than the speed of sound. That’s roughly 5,400 miles per hour (8,690.45 kph), faster than just about any other weapon on the planet.

How far can a railgun shoot?

A railgun’s effective range is closely related to the speed at which it can launch a projectile. Land or ship-based railguns with Mach 6 capabilities are understood to have effective ranges of roughly 126 miles (202.7 km) or 110 nautical miles (177.02 km) at sea.

A brief history of the railgun

When French inventor André Louis Octave Fauchon-Villeplée first introduced the concept of an electromagnetic railgun to the world with a functional, small-scale prototype of an electric cannon in 1918, several weapons engineers around the world took notice and began work on their own futuristic railguns.

It wasn’t until World War 2 that we saw plans for a fully functional, combat-ready railgun laid out. German engineer Joachim Hänsler proposed the creation of what was essentially a railgun – an electromagnetically powered anti-air gun placement. This was to be an iteration on Villeplée's design decades earlier, a ‘cannon’ that utilized a charged current to propel its projectiles forward.

But that’s all Hänsler's idea ended up being: a design. Hänsler’s railgun was never built. In spite of that, word quickly spread about this revolutionary new weapon design. The catch? Despite the weapon being theoretically possible, its sheer energy cost and operational requirements ensured that weapons of this type would not see development for quite some time.

This hypothetical railgun, at its proposed set of specifications, would use enough energy upon firing a single shot to power half of Chicago. Since then, there have been multiple attempts by militaries around the world to get a working prototype out of the drawing board and into the battlefield.

Perhaps the most recent, and high-profile example, of a military attempting to introduce an actual working railgun into its arsenal would be the US Navy’s $500 million railgun project. Although R&D had progressed enough to the point where several functional prototypes had been built, the US Navy recently decided to pull the plug on its ambitious project.

How does an electromagnetic railgun work?

As its name suggests, an electromagnetic railgun utilizes electromagnetic energy to launch its projectiles. This makes it closer in design to a large electric circuit than a gun.

A railgun has three main components: a power supply, rails, and the armature.

The power supply is what delivers current to the railgun. This current consists of millions of volts of electricity. Millions of volts of electricity come from the power supply, which first gets sent to the positive rail.

The rails – where the railgun gets its name – are the lengths of highly conductive metal the current runs through to charge up the projectile. They’re essentially gigantic magnets, and as such, have a positive rail on one side, and a negative rail on the other.

After the current passes through the positive rail, it makes its way towards the armature, which bridges the gap between the two rails. This is typically where the projectile is stored. At this point, the current can then move towards the negative rail, and eventually back to the power supply. 

With all this current circulating throughout the system, a strong magnetic field is formed, and with it, a magnetic force. Like any other force, it has a magnitude and direction. In a railgun, this magnetic force is charged up until it reaches critical levels, and is used to launch projectiles forward with tremendous amounts of force.

Despite its massive potential in both naval and surface-to-air combat, the Navy couldn’t contend with the railgun’s numerous drawbacks. Due to how electromagnetic railguns work, many of these drawbacks are sadly unavoidable.

The potential future of railguns

Recent reports indicate that China intends to pick up where the US Navy left off, with their own take on the railgun. They too have built and tested functional railgun prototypes out on the open sea. Now all that’s left is to make it strong enough to withstand operational requirements.

Chinese researchers have taken cues from previous railgun projects to come up with a design that’s not just functional, but also practical and efficient. For instance, to circumvent the barrel wear faced by the Navy’s railgun, they’ve run experiments using liquid metal, a highly conductive cooling material, to significantly decrease the wear and tear on the railgun’s barrel.

According to their reports, not only could their railgun be much more practical than the Navy’s, but it’ll also launch projectiles at higher velocities and at greater range, too. Their prototype launched a projectile well past Mach 7, hitting a target 155.3 miles (250 km) away.

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