Navy Columbia-Class submarine quieting ‘electric drive’ - stealthiest sub ever? The Navy has now issued at least one-fourth of the design work and begun further advancing work on systems such as a stealthy "electric drive" propulsion system for the emerging nuclear-armed Columbia-Class ballistic missile submarines by 2021. Of the required design disclosures (drawings), 26-percent have been issued, and the program is on a path to have 83-percent issued by construction start,” Bill Couch, spokesman for Naval Sea Systems Command, told Warrior Maven. The Columbia class is to be equipped with an electric-drive propulsion train, as opposed to the mechanical-drive propulsion train used on other Navy submarines. In today’s Ohio-class submarines, a reactor plant generates heat which creates steam, Navy officials explained. The steam then turns turbines which produce electricity and also propel the ship forward through “reduction gears” which are able to translate the high-speed energy from a turbine into the shaft RPMs needed to move a boat propeller. “The electric-drive system is expected to be quieter (i.e., stealthier) than a mechanical-drive system,” a Congressional Research Service report on Columbia-Class submarines from earlier this year states. Designed to be 560-feet– long and house 16 Trident II D5 missiles fired from 44-foot-long missile tubes, Columbia-Class submarines will use a quieting X-shaped stern configuration. The “X”-shaped stern will restore maneuverability to submarines; as submarine designs progressed from using a propeller to using a propulsor to improve quieting, submarines lost some surface maneuverability, Navy officials explained.