Naval railguns: Are the US, China pursuing an unworkable weapon?

China confirmed on March 14 that it is conducting sea trials of an electromagnetically fired railgun, a potentially game-changing weapon that can hit targets at up to 7,800 miles per hour. The US Navy’s chief of naval operations called further attention to the futuristic weapon when he told a congressional subcommittee this month that the US – which hasn’t test-fired a railgun at sea – is “fully invested” in perfecting the device despite reports that the project is being scrapped due to cost and technical factors.

But as China touts its technical prowess and buzz grows in the US about a railgun “gap” with Beijing, Norman Friedman, an international military analyst, questions whether the railgun will ever emerge as an effective naval weapon. He points to hurdles involving repetitive fire, precise targeting and developing compact shipboard power sources that may prove insurmountable for both US and Chinese researchers. 

Friedman also asserts that China’s railgun claims are based more on propaganda than substance. On the US side, he argues that shipboard lasers may provide a more lethal defense against weapons such as the Chinese DF-21D anti-ship missile.

“The US has been playing with railguns for a long time, but there’s been a lot of skepticism as to whether it’s worth the effort,” Friedman told Asia Times.

Railguns tap electromagnetic forces to propel metal projectiles without powder charges. Their theoretical ability to hit sea, air and land targets at up to seven times the speed of sound from ranges of 150 km makes explosive warheads obsolete.

Three hurdles

Friedman says efforts to develop the weapon have been hounded by three major problems: ensuring repetitive fire capability; ensuring precise targeting; and developing shipboard power sources compact enough to fit on a warship. By implication, he says such potential glitches will also complicate a similar push by China – regardless of recent Chinese claims.

On the repetitive fire problem, Friedman notes the challenge involves accelerating projectiles to a high speed and firing them repeatedly as part of a continuous process. This requires not only an onboard generator powerful enough to sustain repeated firing, but also a gun barrel that resists such material abuse.

“There’s always been the feeling that the forces involved would rip-up whatever you were firing,” said Friedman, a network-centric warfare expert who wrote the ‘Naval Institute Guide to World Naval Weapon Systems.’

He says the Office of Naval Research (ONR), which coordinates technology programs for the navy, previously reported that a prototype railgun could fire between 20-30 shots. But it remains to be seen if the gun can be improved to fire hundreds of rounds in quick bursts.

“The US has been playing with railguns for a long time, but there’s been a lot of skepticism as to whether it’s worth the effort”

The second problem, according to Friedman, is how accurately a gun that’s aboard a moving ship can be aimed at a sea, land or air target. “If you’re firing a small, high-speed projectile, it doesn’t take much error for it to miss completely,” Friedman said.

Global Positioning Systems (GPS) that make adjustments for precision targeting from moving vessels have been suggested as solutions. But Friedman says it isn’t clear if such GPS technology will work in battle.

He says another question is what happens when the projectile, made of inert metal, strikes its target. “What is the mechanism of transferring the energy to the target?,” Friedman asks, noting that the projectile would be moving so fast that it could pass completely through, say, the unarmored side of a ship, inflicting minimal damage.

The third hurdle is finding the space on a ship to store the electrical energy needed to power a railgun. Friedman says designing a power plant to meet these specifications may be more difficult than thought.

“The question for a Chinese warship is how much space would you want to give up (for a railgun) and I’m not sure they would be all that hot to do it,” Friedman said.

News blackout?

On the US side, Friedman says the ONR has sometimes unveiled “spectacular” weapons like a railgun that later proved unusable. He notes the project was rolled out by defense contractors several years ago with dramatic videos of a gun-like device blasting projectiles at high speed. But the publicity wasn’t followed by news of other technical coups. “The railgun was being pushed very hard by ONR and then suddenly it seemed to go away. Something appears to have happened,” the analyst said of the silence since.

US Navy Chief of Naval Operations John Richardson conceded that the project is encountering problems when he told a House appropriations subcommittee on March 7 that railgun development faces hurdles related to range, power supply and building a gun barrel that can withstand the heat and pressure of launching projectiles. But Richardson noted that researchers were “doubling down” on the issues.

Military researcher Joseph Trevithick told Asia Times in a February 20 article that the US Navy hasn’t abandoned the railgun and that its 2019 fiscal year budget shows that R&D for the naval supergun will continue. Trevithick also stressed the railgun’s cost and logistical benefits, resistance to jamming and ability to hit time-sensitive targets that missiles miss.

But Friedman believes shipboard lasers can do a better job of hitting hypersonic missiles, anti-ship missiles and drones, though other analysts argue they aren’t fail-proof defenses against such threats.

“Directed-energy weapons are very promising, but they’ve been very promising for a long time,” Friedman admits, pointing to the pitfalls in developing new military technologies like lasers.

One wild card in developing lasers as military weapons is whether artificial intelligence systems will eventually improve the ability to target “swarm” attacks from incoming missiles and drones.

Is China ahead?

China’s claims of successful railgun tests at sea are based on an article that appeared on the People’s Liberation Army (PLA) news portal 81.cn. Zhang Xiao, an associate research fellow at the Wuhan-based PLA Naval University of Engineering, is quoted as saying the successful firings came after hundreds of failures and more than 50,000 tests.

Friedman cautions that such Chinese claims must be regarded skeptically. Outside of classified military intelligence, the analyst says it’s nearly impossible to check the veracity of such purported breakthroughs. There’s also a tendency by US media to report news of wonder weapons on various Chinese government websites without critical analysis.

According to Friedman, this is what Beijing wants. “Chinese policy has been to demonstrate spectacular technology capability which may or may not be real,” Friedman said. “You get the feeling they’re willing to kill themselves to do a one-off demonstration that doesn’t represent real capability.”

The bottom line, Friedman says, is “nobody knows how good the Chinese military really is.”