A small-scale Zumwalt-class destroyer test model in Lake Pend Oreille.
The United States Navy loves the idea of the railgun and has been toying (expensively) with the technology for years. The battleship-mounted guns use electricity, rather than combustion, to propel a nonexplosive projectile several times the speed of sound more than twice the distance of other shipborne weapons. Plus, because the ordnance doesn't explode on impact, the Navy doesn't have to worry about unexploded ammunition laying around once hostilities have ceased.
While railguns have been the stuff of science fiction, the Navy has unveiled a ship—designed in part at the Acoustic Research Detachment
in Bayview, Idaho—that it hopes to arm with one of the high-tech weapons. Trouble is, the gun doesn't work
The problem with railguns is that they're electricity hogs. While the Zumwalt-class destroyer
, which has stealth capability as well as a railgun, is powered by a 78-megawatt array of turbine generators, the gun alone requires 25 megawatts—approximately enough energy to power
between 10,000 and 22,500 homes. In other words, firing the Zumwalt's railgun once would take about a third of the ship's operational capacity. According to Popular Science
, most battleships don't have more than 9 megawatts to spare
The Zumwalt will instead go to sea with more conventional—though powerful—155 millimeter guns, 30 millimeter guns and 80 missile tubes. While the railgun will have to wait, technology isn't the Zumwalt's only hard-to-manage feature. They're also some of the most expensive weapons in the U.S. arsenal. In a 2008 report
from the Government Accountability Office, the Zumwalt program—which at that time had already cost more than $13 billion—was characterized as facing "significant execution risks."
Designed and tested in small-scale forms at the North Idaho base where the Navy also conducts work on its submarine fleet, three full-size Zumwalts have been ordered to date, costing a combined $12.5 billion
. The first ship is heading to sea this year, with the third expected in 2018. All told, the project is expected to run to $22 billion.