Railgun latest deadly technology

• Regarding projectile development, research will not be confined to standard armour-piercing rounds.
• ATLA documents reveal that railguns are anticipated to be operational as either naval or land-based artillery systems.
• ATLA successfully conducted the first shipboard firing test of a railgun in October 2023.

A railgun, occasionally referred to as a rail cannon, constitutes a linear motor device primarily engineered as a ranged weapon. It employs electromagnetic force to accelerate high-velocity projectiles, which typically do not contain explosives; instead, their destructive capacity relies on their high kinetic energy.

This device features a pair of parallel conductive rails along which a sliding projectile, known as an armature, is propelled. The acceleration of the armature occurs through the electromagnetic effects generated by a current that traverses one rail, enters the armature, and returns via the other rail.

As of the year 2020, considerable research has been dedicated to railguns as potential military weapons that utilise electromagnetic forces to impart significant kinetic energy to projectiles, such as dart ammunition, as opposed to conventional propellants. While traditional explosive-powered military firearms achieve a muzzle velocity of approximately two kilometres per second (Mach 5.9), railguns can exceed velocities of three kilometres per second (Mach 8.8). Furthermore, for comparable projectiles, the range of railguns may surpass that of conventional firearms. The destructive force exerted by a projectile is contingent upon its kinetic energy, which is proportional to its mass and the square of its velocity now of impact.

Despite decades of research and development, railguns remain in the investigatory stage, and it is uncertain whether they will be implemented as viable military weapon systems soon.

Basics

A railgun is different from a traditional electric motor because it doesn't use extra field windings or permanent magnets. It has a simple design with a single loop of current. This design needs very high currents—about one million amperes—to achieve enough acceleration and speed.

An augmented railgun is a common type that improves performance by channelling the current through extra pairs of parallel wires. This setup strengthens the magnetic field around the moving armature. The armature can be part of the projectile, or it can be set up to accelerate a separate projectile that doesn't conduct electricity.

Railguns are of interest for military uses because they can achieve much higher projectile speeds than standard guns that use chemical propellants. These higher speeds, together with better streamlined projectiles, can lead to longer firing ranges. Additionally, higher speeds can help with using kinetic energy projectiles that can precisely hit targets, instead of using explosive shells.

Railgun speeds are usually like those of two-stage light-gas guns. However, light-gas guns are mostly used in labs, while railguns are seen as having real potential for military development. For instance, a prototype of a Combustion Light Gas Gun, with a 155 mm barrel, is expected to reach speeds of 2500 m/s.

Weaponry

Railguns are being studied as weapons that shoot projectiles without using explosives or propellants. Instead, they reach very high speeds of 2 500 m/s (about 8,200 ft/s), which is around Mach 7 at sea level. For comparison, the M16 rifle has a speed of 930 m/s (3,050 ft/s), and the 16-inch/50-calibre Mark 7 gun from World War II has a speed of 760 m/s (2,490 ft/s). Although the Mark 7 gun’s projectiles are much heavier (up to 2 700 pounds), they generate a power of 360 MJ and have a kinetic impact energy of over 160 MJ. Railguns can fire smaller projectiles at high speeds, producing impact energy equal to or greater than the 5"/54 calibre Mark 45 Naval guns, which reach up to 10 MJ at the muzzle, but with a longer range.

Railgun technology requires long and heavy barrels, yet its performance outmatches traditional cannons of the same length. The first planned railgun for production is the General Atomics Blitzer system, which started testing in September 2010. This weapon fires a special discarding sabot round made by Boeing's Phantom Works at a speed of 1,600 m/s (around 5,200 ft/s) with accelerations over 60 000 gn.

A fast, low-flying anti-ship missile can appear just twenty miles from a warship, giving the ship very little time to react. Even if regular defence systems respond quickly, they can be costly, and ships can only carry a limited number of large interceptors. BAE Systems once considered adding railguns to their Future Fighting Vehicle.

India has successfully tested its railgun, while Russia, China, Turkey (through ASELSAN), and Yeteknoloji are also working on developing railguns.

Latest status

In the Japanese Ministry of Defence, the development of railgun technology is spearheaded by the Ground Systems Research Centre (GSRC), which operates under the Acquisition, Technology & Logistics Agency (ATLA). The ambitious initiative to create a railgun system commenced in 2016 as part of a project titled “Research on Electromagnetic Acceleration Systems.” 

Unlike traditional firearms, which experience barrel wear and damage primarily from the explosive pressure of gunpowder, railguns face unique challenges. The primary concerns involve the thermal stress and potential degradation caused by the substantial electric currents that flow through the rail system, along with the mechanical wear from the contact between the armature and the rail surface. 

In a significant milestone, ATLA successfully conducted the first shipboard firing test of a railgun in October 2023. Building on the findings from earlier phases of research, the project is now entering a new stage termed “Research on Future Railgun,” slated to take place from FY2022 to FY2026. 

A key area of focus is the stability of projectiles in flight. For a railgun to be effective, the projectile must remain aerodynamically stable after exiting the muzzle; without this stability, accurate targeting akin to conventional artillery cannot be achieved. Consequently, the development of a sophisticated fire control system is imperative. Ongoing research efforts are dedicated to designing a fire control solution that is specifically crafted for the distinct operational characteristics of railguns, particularly their high muzzle velocities and low ballistic profile.

While large-scale power generators and storage units would theoretically meet the energy demands of a railgun, their size renders them impractical for use on mobile platforms such as naval vessels or armoured vehicles. 

ATLA documents reveal that railguns are anticipated to be operational as either naval or land-based artillery systems. In naval applications, they are expected to play a critical role in intercepting incoming threats, particularly advanced anti-ship missiles, including hypersonic cruise missiles that challenge traditional interception methods due to their extreme velocities. 

For land-based applications, railguns are envisioned to be utilised for counter-battery fire against enemy artillery units positioned well behind front lines, effectively filling a role like that of conventional howitzers.

Regarding projectile development, research will not be confined to standard armour-piercing rounds. It will also delve into innovative designs for airburst munitions—rounds specifically engineered to detonate in mid-air, producing lethal fragments optimised for use in anti-air warfare scenarios. 

In a notable collaborative effort, Japan’s ATLA and the French German Research Institute of Saint-Louis (ISL) signed a Terms of Reference (TOR) last year to explore opportunities for joint research, development, testing, and evaluation of innovative railgun technologies. This partnership underscores the international interest in advancing railgun systems and enhancing their practical applications in modern warfare.