According to the Hong Kong Asia Times website on April 22, Japan's ship-based electromagnetic railgun fires shells at hypersonic speed by using electromagnetic energy, which provides a cost-effective and effective rapid response method for dealing with possible missile "saturation attacks" in the future.

  According to the French Naval News website, the Japanese Maritime Self-Defense Force disclosed this month that the "Aobi" practice ship deployed advanced electromagnetic railguns, marking an important milestone in the field of electromagnetic weapons.

  The electromagnetic railgun was developed by the Ground System Research Center under the Defense Equipment Department of the Ministry of Defense of Japan. Research began in 2016 and the first ship-based shooting test was conducted in October 2023.

  The weapon system demonstrates a higher initial speed, reaching 2,000 meters per second, and can stably fire up to 120 shells, overcoming challenges in orbit wear and shell flight stability. The current study aims to transition to a complete "artillery system" that integrates continuous firing, improved shell flight stability and customized fire control systems.

  Japan's electromagnetic railguns could enhance the navy's missile defense capabilities and provide new options for land-based artillery, such as anti-artillery firepower and coastal strike capabilities, which theoretically help intercept specific high-speed missile threats. However, the key issue in actual deployment remains the miniaturization of power supplies.

  Through cross-border cooperation, Japan's electromagnetic railgun has been developed and is expected to mature technology and combat capabilities by fiscal 2026.

  The U.S. Navy suspended the electromagnetic railgun project in July 2021, mainly due to challenges such as excessive power, overheating of equipment and track wear. Japan continues to promote research on this technology to solve the shortcomings in missile defense and strike capabilities.

  Missiles offer powerful long-range strike options, but they are extremely expensive and are limited by the capacity of the ship-based ammunition repository. The vertical launch systems of the U.S. Navy destroyers and cruisers can carry only 96 and 122 missiles, respectively.

  During its operations against the Houthi forces from 2023 to 2025, the United States used hundreds of valuable missiles to shoot down relatively cheap drones and ballistic missiles, highlighting the unsustainable cost issues and the risk of ammunition depot restrictions.

  Japan also faces similar problems. In December 2022, Kyodo News reported that Japan's interceptor missile inventory was only 60% of what national defense needed.

  In addition to the limited capacity of the ammunition repository, the inability to reload vertical launch system missiles at sea is another major limitation.

  Some defense experts mentioned that although the US Mk-41 vertical launch system is very effective, its missile launch unit must be reloaded at the port. Experts pointed out that early attempts to load ammunition with foldable cranes on U.S. warships ended in failure due to the challenges of loading heavy cartridges in harsh sea conditions.

  It can take weeks for the ship to return to a port capable of reloading the vertical launch system. Large-scale missile volley attacks could quickly deplete the vertical launch system ammunition depot in high-end combat scenarios.

  Electromagnetic railguns can provide a critical solution for these missile defense bottlenecks. In a December 2011 article by the Proceeding of the American Naval Society, policy analyst Maxwell Cooper pointed out that the shells fired by electromagnetic railguns were comparable to most missiles, with the same lethality and accuracy, while at the same time lower cost and greater quantity.

  Cooper explained that the shells fired by electromagnetic railguns can reach hypersonic speeds, and the shells use their own huge kinetic energy to create a destructive effect without explosives filling. He also suggested that shells could be equipped with satellite positioning devices to improve strike accuracy. Furthermore, since they do not fire gunpowder, some ammunition space can be freed up.

  However, while electromagnetic railgun shells are smaller and cheaper than missiles, they still require considerable space for ship-based power and ammunition stocks.

  Cooper mentioned that the lack of a powerful multi-purpose artillery forced the U.S. Navy commander to use expensive, limited-number high-end missiles for all types of targets, and a relatively economical means to deal with low-end threats (such as patrol boats, unguarded coastal targets and basic ballistic missiles). These targets could have been dealt with with less cost shells.

  Electromagnetic railgun is also a cost-effective means to combat missile "saturation attack". In April 2022, a report from the U.S. Congressional Research Services Department pointed out that an 11-kilogram electromagnetic railgun shell could release more than 500 tungsten projectiles weighing pellets that could destroy incoming missiles through pure kinetic energy. (Translated by Guo Jun)

[Editor in charge: Wang Jinzhi]