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Potential Chinese Railgun Testing Illustrates the US Navy’s Biggest Long-Term Challenge

Justin Bronk
RUSI Defence Systems, 1 February 2018
China, Military Sciences, Martial Power Project, Maritime Forces, Technology, Pacific
Pictures of what appears to be a test installation of a naval railgun on a PLA Navy landing ship suggest China is moving forward with sea trials of a weapon which can threaten all Western surface assets. At the start of a huge ship-building plan, China is ideally placed to capitalise on this technology.

Defence technology watchers on social media have been intrigued by photographs taken in Wuchang shipyard of a modified PLA Navy Type 072 III landing ship, pennant number 936 Haiyangshan.

This otherwise unremarkable amphibious landing and support vessel has had its normal defensive 37 mm bow cannon mount replaced with a huge enclosed gun turret with what appears to be an electromagnetic railgun barrel.

Image from Twitter via @xinfengcao

Several factors suggest that this is an electromagnetic railgun rather than a conventional ‘gunpowder’ cannon mounting. First, the barrel profile appears to be much shorter and broader than modern naval artillery tubes. It also features a stepped design similar to those developed by the likes of BAE Systems and General Atomics for the US Navy’s own railgun development programme.

Second, the fore deck area behind the bow and cannon mount has been filled with various containers that would be perfect for the capacitors, generators and cooling equipment required for electromagnetic railgun testing on such a small vessel.

Image from Twitter via @xinfengcao

Finally, the cannon and mount are far too large for normal installation on such a small vessel as the Type 072 III and would likely cause significant stability and seaworthiness issues in general blue-water service. This only serves to confirm that this is almost certainly a test installation for sea trials of a prototype weapon rather than a conventional up-gunning of an existing class of ship. However, together with the barrel profile and apparent containerised power pack, it further supports the railgun hypothesis.

Last October, Rear Admiral Ma Weiming of the People’s Liberation Army Naval University of Engineering acknowledged for the first time  China’s railgun development and testing programme, when he announced an unspecified major breakthrough in the installation of integrated electric-power systems on naval vessels. This is a critical requirement for the routine installation of railguns on major surface combatants due to the enormous power generation and storage capacity required for high-velocity railgun shots especially at high rates of fire. The US Navy’s new Gerald Ford class of aircraft carrier and experimental DDG-1000 Zumwalt class destroyers are currently the only operational ships specifically designed to incorporate the required excess power capacity for railguns and other electromagnetic weapons into their power-packs.

However, despite more than a decade of development work and many successful land-based firing trials the US Navy has still not undertaken sea trails with either BAE Systems’ or General Atomics’ railgun prototypes and the latest US Navy budget request suggests a toning down of American ambition to field an operational system. Instead, the Pentagon’s current focus is to adapt the hyper-velocity projectile developed for the railguns to fire from existing 5-inch naval cannons and 155 mm artillery pieces on land. While this would enhance performance and allow muzzle velocities of around Mach 3 from existing gunpowder artillery systems, such an approach falls far short of the potential for true electromagnetic railguns. Railguns offer muzzle velocities for the same projectiles of over Mach 7 with revolutionary increases in range, lethality, accuracy and flexibility as a consequence.

What makes railguns so deadly is the sheer velocity of their projectiles even at extreme ranges beyond the horizon. A solid tungsten projectile fired at Mach 7 will arrive at the horizon in less than five seconds with more kinetic energy at the point of impact than the 120 mm APFSDS rounds fired by an M1A2 Abrams main battle tank at the muzzle. Such projectiles are almost impossible to intercept using any existing close in weapons system or missile-based interceptors once launched. Therefore, defence of major surface combatants from enemy vessels armed with mature railgun technology would have to rely on destroying them far enough away to prevent successful firing and completion of the kill chain. This is unlikely to be possible for the US Navy in congested and contested waters, such as the Malacca or Taiwan Straits or indeed in the South or East China Seas, where Chinese submarines and aircraft could provide PLA Naval surface combatants with targeting data beyond the range of the latter’s own radar systems.

Railguns also offer advantages in magazine depth because the projectiles are inert and much smaller and cheaper than anti-ship and air-defence missiles. They are also safer to store in case the ship carrying them suffers battle damage. Given the extremely high potential muzzle velocities and flat trajectory of railgun projectiles, they are also potentially powerful air and missile defence weapons in addition to their obvious potential against surface combatants and land-based targets. This is why the US Navy, as well as China, the UK and Japan are all known to be exploring the technology.

Fundamentally, however, the images of the Haiyangshan suggest that China is moving ahead of the US Navy at least in terms of developing a weapon prototype worth taking out for sea trials. The BAE and General Atomics prototypes may well have technical advantages over the mysterious PLA Navy weapon, but the technology itself is relatively simple conceptually. It is making it work in practical terms that is a huge challenge for materials scientists and naval engineers. The move towards repurposing the hyper-velocity projectile away from true railgun applications back towards enhancing existing but fundamentally limited conventional gun systems is illustrative of the US Navy’s greatest difficulty – its huge extant blue-water fleet.

Due to the huge power generation, capacitor and cooling requirements of a high-energy railgun main armament, an existing destroyer or cruiser would need to be gutted and almost completely rebuilt with new advanced power pack, and space found for the large, heavy capacitors and cooling apparatus. It is essentially uneconomical for the US Navy to adapt its huge Arleigh Burke DDG and Ticonderoga CG fleets to incorporate railguns, no matter what the combat effectiveness benefits might be. The failure of the DDG-1000 project to deliver a practical and affordable replacement for the Arleigh Burke design means that the US Navy is not able to both maintain its fleet size requirements and transform to incorporate electromagnetic main armament into its ships.

By contrast, the PLA Navy has huge blue-water ambitions, but is currently in the early stages of the planning and construction of such a fleet. Its first new Type 055 destroyer – reportedly of nearly 10,000 tons displacement and with a 100MW+ power generation capability – is intended to be the first of many such vessels launched over the next decade and a half to form the backbone of the planned carrier battlegroups. These ships are large enough, with enough power and crucially design flexibility to incorporate game-changing railgun technology and challenge the supremacy of US Navy surface combatants.

The appearance of the Haiyangshan’s new test configuration and Rear Admiral Ma Weiming’s confident announcement last October both point to a Chinese Navy aware of the promise of railguns and determined to make use of the technology in their future fleet.

Justin Bronk
Research Fellow for Airpower and Military Technology at RUSI.

Author

Justin Bronk
Research Fellow, Airpower and Technology

Justin Bronk is a Research Fellow specialising in combat airpower and technology in the Military Sciences team at RUSI. He is also... read more

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