American Superconductor and Navy Test HTS on USS Higgins
American Superconductor Corporation, announced that it has supplied critical components to the Office of Naval Research (ONR) and the Naval Surface Warfare Center Carderock Division (NSWCCD) Ship Engineering Station Philadelphia for a high temperature superconductor (HTS) degaussing coil system that has successfully completed initial electrical testing onboard the USS Higgins (DDG 76), an 8,000-ton Arleigh Burke-class destroyer. Powered by AMSC’s HTS wire and magnet cable technology, the coil system will undergo U.S. Navy sea trials over the next two years on the Higgins.
Degaussing systems containing multiple tons of copper wire are utilized in most naval ships to cloak their magnetic signature, thereby making them much more difficult to be “seen” by magnetic sensors and magnetically activated mines. These systems are composed of a network of electrical cables installed around the circumference of a ship’s hull, running from the bow to the stern on both sides of the vessel. AMSC produces HTS wires that conduct more than 150 times the electrical current of copper wires of the same dimensions. With this “power density” advantage, the Navy estimates that HTS degaussing systems projected for the LPD-17, LCS, CG(X), DDG-1000, and CVN-21 classes of ship will show a 50%-80% reduction in total system weight and a reduced total ownership cost compared to the current copper-based systems. In addition, a 90% reduction in the total installed cable lengths for all Navy ship classes is expected. “With the ability to reduce the size, weight and cost of ship motors, generators, power cables and degaussing systems, HTS wire holds tremendous promise in the maritime market,” said Dan McGahn, senior vice president and general manager of AMSC Superconductors.
AMSC has a lengthy history working with the U.S. Navy and the U.S. Department of Defense (DOD). In April 2006, the company completed the successful demonstration of the world’s first full-scale superconductor-based degaussing coil, an internally funded research and development program. The 142-foot (40 meter) HTS degaussing coil produced 4,100 Amp (AMLYY)-turns, a typical level of performance of conventional copper-based degaussing systems deployed in military ships today. AMSC’s degaussing coil achieved this with an operating voltage of less than 0.5 volts, 1,000 times lower than copper-based systems. In March 2007, AMSC completed factory acceptance testing of a 36.5 megawatt (49,000 horsepower) HTS ship propulsion motor for the U.S. Navy. AMSC designed, developed and manufactured the motor along with strategic partner Northrop Grumman (NOC) under a contract from the U.S. Navy’s Office of Naval Research (ONR). The motor was developed to demonstrate the efficacy of HTS primary-propulsion-motor technology for future Navy all-electric ships and submarines. The HTS motor is less than one-half the size and weight of the current baseline DDG 1000 propulsion motor and is more efficient over a much wider range of ship speeds. This results in weight and space advantages, enabling a significant increase in weapons payload capacity such as more powerful radar and additional missiles. This same advantage applies to commercial vessels. The HTS motor is currently awaiting load testing by the U.S. Navy.