Images that surfaced on social media last week that appeared to show an electromagnetic rail gun mounted on the Chinese Type 072II Yuting-class tank landing ship, “Haiyang Shan.” Thus far, reports are more speculation than fact, with China remaining tight-lipped about the purposes of the weapon or how mature the technology truly may be. However, many experts contend that despite beating the United States to mounting one of these weapons on a warship, China still faces a laundry list of technological hurdles before being able to introduce rail gun technology to warfare.

US Navy responds to Chinese rail gun reports with its own 'hypervelocity' projectile test

The United States, likewise, has not yet developed an electromagnetic rail gun that it feels is reliable and efficient enough for service aboard an operational warship, but that didn’t stop the U.S. from raining on the Chinese parade a bit by unveiling its own “hypervelocity” projectile test. This test actually took place last summer during the Rim of the Pacific (RIMPAC) 2018 international exercises that included naval participants from a number of friendly nations. Although the Navy has confirmed that the test and results are not classified, the Department of Defense has been none-the-less tight-lipped about the details.

What we do know for certain is that the test was conducted using the Mk 45 5-inch deck gun aboard the USS Dewey (DDG-105). The hypervelocity projectiles, referred to as HVPs, that were fired from the gun were originally intended for use in electromagnetic rail guns themselves, but thanks to some slight modifications, the test proved that the Navy’s existing ship-board guns could be converted to fire the kinetic projectiles at speeds approaching Mach 3. They also boast a significant increase in range over traditional deck-gun munitions, at 40 or more miles over the existing munition’s 13-mile range. At a fire-rate of 20 rounds per minute, that translates into a hell of a lot of fast-moving firepower.

US Navy responds to Chinese rail gun reports with its own 'hypervelocity' projectile test
By utilizing existing Mk 45 guns and loading systems, the HVP can maintain the Navy’s 20-round-per minute rate of fire with the new projectiles. (WikiMedia Commons)

Most importantly, however, these munitions can be used to intercept inbound ballistic missiles while costing significantly less than the missiles the Navy currently uses for that job. The Navy’s suite of Rolling Airframe Missiles, Standard Missile-2s, and Evolved Sea Sparrow missiles all cost a million dollars or more each. In one incident in 2006, the USS Mason fired three of these missiles at what were believed to be two inbound Iranian cruise missiles, making that short engagement a $3 million or more volley. The HVPs on the other hand, cost between $75,000 and $100,000 each (depending on the specific round), marking a vast savings over missile-to-missile intercepts.

“So if you think about the kinds of threats you might face in the Middle East, the lower-end cruise missiles or a larger UAV, now you have a way to shoot them down that doesn’t require you use a $2 million ESSM or $1 million RAM because a hypervelocity projectile – even in the highest-end estimates have it in the $75,000 to $100,000 range, and that’s for the fanciest version of it with an onboard seeker,” Bryan Clark of the Center for Strategic and Budgetary Assessments explained.

“You can get 15 rounds a minute for an air defense mission as well as a surface-to-surface mission,” Clark said. “That adds significant missile defense capacity when you think that each of those might be replacing an ESSM or a RAM missile. They’re a lot less expensive.”

Despite the successful test, there’s no word on plans to adopt HVPs across the Navy quite yet, but plans are underway to see if conversions of the same sort can be done with Army and Marine Corps ground-based 155mm artillery assets, and rumors that this weapon could serve as a replacement for the troubled Zumwalt-class destroyers’ main weapon system (the 155mm Advanced Gun System) which has been all but canceled.