Groups of Navy brass and the inventors who support them lined up in the cavernous Walter E. Washington Convention Center last week to take a photo with their 33-foot-long star: The electromagnetic railgun.
The Navy has worked on the railgun since 2005, and Wednesday marked its public debut in Washington. The Navy considers development of railgun technology one of its top modernization goals.
When it is fired, a massive electric pulse shoots into the railgun’s barrel, jumpstarting rings of magnetic fields that force a projectile out at speeds over 4,500 miles per hour – six times the speed of sound — and over a distance of more than 100 miles, according to the Navy.
BAE Systems won a $21 million contract in 2009 to develop its prototype. In 2013, it was awarded an additional $35 million contract to build its follow-on, which would fire more shots at once than its predecessor. The Navy expects to have the railgun fully operational in the mid-2020s.
The “bullets” themselves, projectiles that are also under development, are expected to cost about $25,000 each.
Getting the railgun on its ships will help the Navy reduce both risk and vulnerability, Chief of Naval Operations Adm. Jonathan Greenert said.
“Probably the biggest vulnerability of a ship is its magazine [ammunition storage], because that’s where all the explosives are. Imagine getting rid of that. And the cost … $25,000 a round,” compared with more than $1 million a shot for the Navy’s Tomahawk cruise missile, Greenert said.
“Get me off gunpowder,” he told the assembled crowd, in town for the Naval Future Force Science and Technology Expo.
Next year, the railgun will undergo its first trials, when it will be installed aboard a Joint High Speed Vessel for shipboard testing.
But the 2016 test will have limitations: the high-speed vessel can be thought of like a high-speed barge — open with a clear deck that can be modified for missions, but is nothing like the platforms the railgun is intended for.
The potential homes of the railgun — aboard DDG-51 destroyers and CG-47 cruisers and their future replacements — are already under tight weight and space constraints. Both vessels have radar and sensor suites, missile defense packages and conventional Navy guns that demand space both on deck and support space inside the hull, and they have to be continuously monitored for weight to not overstress ship hulls.
The railgun itself would be on deck, but the components necessary to generate and retain an electrical pulse would be below, said Cmdr. Jason Fox, a program manager for the railgun at Naval Sea Systems Command.
“With a ship there’s always space and weight issues,” Fox said. “You don’t get anything for nothing.”
The tradeoff would be to gain some of the space currently dedicated to the missiles the railgun is intended to replace.
“We know we can make it fit on multiple ships within the inventory right now,” Fox said.
In addition, creating the enormous blast of power required to launch a projectile at almost six times the speed of sound generates heat concerns for ships, which the Navy is addressing through the material in the railgun barrel, Winter said.
The early versions of the capacitors, the rows and rows of support equipment that stores electric energy to have it ready to fire, started out consuming the space of a large room. Ten years into the program, engineers at the Office of Naval Research have cut that size down by three-quarters, making next year’s test possible.
General Atomics is also building a prototype, but it is BAE’s model that will undergo sea testing next year.
