An Update on Railgun

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Julian E Barnes, Navy Develops New Supergun; The experimental railgun is designed to keep the US military's edge over Russia and China. Wall Street Journal, May 28, 2016.
http://www.wsj.com/articles/a-fi ... supergun-1464359194

Excerpt in the window of print: The high-tech railgun projectile exits muzzle at 4,500 miles an hour

Quote

"Officials huddled at a video screen for a first look at a deadly new supergun that can fire a 25-pound projectile through seven steel plates and leave a 5-inch hole.

"In conventional guns, a bullet begins losing acceleration moments after the gunpowder ignites. The railgun projectile gains more speed as it travels the length of a 32-foot barrel, exiting the muzzle at 4,500 miles an hour, or more than a mile a second.

"Inside the test bunker at Dahlgren, military officials turned to the video monitor showing the rectangular railgun barrel.

"Wires splay out the back of the railgun, which requires a power plant that generates 25 megawatts—enough electricity to power 18,750 homes.

"The age of the gun faded after World War II, hampered by the limited range and accuracy of gunpowder weapons. Missiles and jet fighters dominated the Cold War years, prompting the Navy to retire its big-gun battleships. The railgun—and its newly developed projectiles—could launch a new generation of the vessels.

"The Navy’s current 6-inch guns have a range of 15 miles. The 16-inch guns of mothballed World War II-era battleships could fire a distance of 24 miles and penetrate 30 feet of concrete. In contrast, the railgun has a range of 125 miles, officials said, and five times the impact.

"The Navy now believes it has a design that soon will be able to fire 10 times a minute through a barrel capable of lasting 1,000 rounds [during lifetime of the railgun (gun barrel and electromagnetic rails) ].

"Unlike the Reagan-era initiative [Star Wars missile defense], the Pentagon doesn't see the railgun as a shield against intercontinental ballistic missiles [ie, a railgun projectile can not reach space] but defense against shorter-range conventional missiles.

"Russia mostly impressed U.S. military planners with the power and precision of its cruise missiles deployed in Syria, and its improved artillery precision revealed in Ukraine.

"Missile defense by the railgun is at least a decade away, but Pentagon officials believe the weapon’s projectiles can be used much sooner.

"The electrical energy required to fire a railgun means it is likely to be used first as a ship-mounted weapon. Only one class of Navy ship, the Zumwalt-class destroyer, has such a power plant, officials said. The Navy is building just three of those destroyers, so the Pentagon is working to adapt the projectile to use in existing Naval guns on other vessels, as well as for Army artillery.  While slower than a railgun, a powder-fired railgun projectile still flies at 2,800 miles an hour, which extends the range and power of existing weapons.


Note:
(a) There is no need to read the rest of the report. We are familiar with railgun, but the report writes as if it is a novel concept.
(b) Dahlgren, Virginia
https://en.wikipedia.org/wiki/Dahlgren,_Virginia
(Since 1918, Dahlgren has been the site of a US Naval base named for Rear Admiral John A Dahlgren)