The Japanese, Electro-Magnetic Guns and Aegis Destroyers


In 2015, a Japanese RFP for the development of electro-magnetic rail guns for their aegis destroyers was issued.

In an article published on Navy Recognition on July 22, 2015, details of the development were highlighted.

According to the Japanese Ministry of Defense (MoD) request for proposal (RfP) to bidding contractors, the 27DD destroyers will incorporate a number of design changes compared to the first batch of Atago class guided missile destroyers.

First, the hull of 27DD has been enlarged to an empty displacement of 8,200 tons compared to the original Atago’s 7,700 tons. It is believed in the Japanese defense community that the enlargement of the hull was conceived in order to provide a necessary growth space for advanced naval weapon systems that are currently under development in Japan, and will be incrementally added to the ships’ arsenal as they are developed — such as railguns and laser point-defense systems.

Like all Japanese combatant ships now being constructed, the 27DD destroyers will be powered by a COGLAG propulsion system (these two, as would be explained again later, would represent a series of essential improvements to the ships’ space and power management and distribution in light of the new weaponry that they will operate in the near future). 

On the more minor technical front, the new ships will also equip a new surface-search radar (the AN/SPQ-9B from Northrop Grumman), new anti-ship missiles, a multi-static sonar system, and an enhanced Aegis combat system that will offer better Cooperative Engagement Capability (CEC).

Eventually, the Japanese MoD envisions their new AEGIS ships to be the first operating platform of an indigenous naval railgun and laser point-defense system that they are locally developing in Japan. The plan for the railgun armament was outlined in their recently published FY2015 defense budget report…..

Now the Japanese have released a video showing their new rail gun under development.

On 31 July, Acquisition, Technology & Logistics Agency has released video footage showing a prototype of electromagnetic railgun for the first time. This is the first official confirmation of the development of a program a new generation of weapons systems for Japan Self-Defense Forces.

Details of the Japanese railgun programme have not yet been made available. It is noted that this electromagnetic railgun weapons system may be outfitted aboard on next-generation destroyers, possibly the Type 27DD.

The railgun utilizes a combination of electric and magnetic force to fire a projectile by means of a sliding armature that is accelerated along a pair of conductive rails. The railgun uses a pair of parallel conductors, or rails, along which a sliding armature is accelerated by the electromagnetic effects of a current that flows down one rail, into the armature and then back along the other rail.

The electromagnetic railgun is capable of firing a projectile 100 miles away and has a low cost of projectiles compared to conventional weaponry.

On top of the reduction in costs per projectile, the railgun limits the need to maintain a large quantity of heavy explosive tipped shells, increasing safety on board navy vessels, and reducing logistics costs and needs. Ships at sea can afford to stay out for longer periods without resupply, reducing the burden of at sea replenishment operations.