An experimental electromagnetic rail gun (EMRG) was successfully test-fired by the Office of Naval Research (ONR) at the Naval Surface Warfare Center lab at Dahlgren, Virginia, in late January. The gun launched a seven-pound aluminum projectile at 5,550 miles per hour, sending it across a 72-foot test course in 10 milliseconds.
Navy officials say if development is successful, the gun eventually could be fielded on board surface combatants for long-range naval fire support for Marine Corps and Army units ashore. They add, though, that an operational EMRG won't be available until around 2020 at the earliest. The gun could go on board next-generation surface combatants in the 2020-2025 timeframe and be backfitted to operational ships.
The rail gun is an ONR "Innovative Naval Prototype" initiative, one of several highrisk, high-reward projects that could provide war-winning capabilities if successfully transitioned to Fleet operators.
The rail gun uses electrical energy to fire solid-metal projectiles at super-high velocities out to ranges greater than 200 nautical miles. The rounds, which do not have explosive warheads, destroy targets with kinetic energy alone. The extended range will enable ships providing gunfire support to remain farther off shore than now is possible.
Navy Ticonderoga-ciass cruisers and Arleigh Burke-class destroyers are armed with the 5-inch/54-caliber Mk 45 deck gun, which has a range of about 13 miles. The Mk 45 is being upgunned to 62-caliber to fire Navy extended-range guided munitions to ranges beyond 62 nautical miles. The Zumwa/r-class landattack destroyer will be armed with two 155mm advanced gun systems capable of firing long-range land-attack projectiles to even longer ranges.
The extremely high velocities generated by the rail gun will give the kinetic projectile a devastating explosive effect. Electric power provides a uniform, highly consistent propulsion charge that enhances accuracy. Because the rail gun doesn't require explosive shells, it will free up magazine space for additional electromagnetic projectiles or other mission equipment and enhance the safety of ammunition handling.
BAE Systems and General Atomics received ONR contracts for a 30-month-long science-and-technology phase for development of rail gun technology and assembly of a weapon capable of firing a projectile to a velocity of 32 megajoules. A joule is a unit of energy capable of lifting a small object such as an apple one meter into the air, January's test was at ten megajoules. Future work aims at development of a 64megajoule system. Boeing, the Charles Stark Draper Laboratory, the Naval Surface Warfare Center's Dahlgren and Carderock divisions, the Naval Undersea Warfare Center, the U.S. Naval Academy, and the Naval Postgraduate School also support the work.
The Navy has looked at electromagnetic weapons technology in the past. In the early 1990s the undersea warfare center investigated an electromagnetic torpedo launcher for potential use on board attack submarines. The Army and Marine Corps have collaborated on development and demonstrations of electromagnetic guns for armored vehicles. Fielding that technology, however, remains a prospect for the long-term future.
Providing the shipboard power needed for electromagnetic weapons, as well as other advanced power-intensive systems, remains a critical challenge for Navy ship designers. The Navy's long-envisioned all-electric ship, championed by former Chief of Naval Operations Admiral Carlisle A. H. Trost in the late 1980s and Secretary of the Navy Richard Danzig for the DD-21 program (later the DDX and now the Zumyvalt class), calls for new power generation and distribution systems that would provide the needed electrical capacity. Those plans slipped further into the future, however, when the Navy decided to use a less ambitious advanced induction motor for the first two Zumwalt-class ships. Superconducting motors remain in development at Navy and industry laboratories, and could go on board later ships of the class.