The US Navy has begun fitting key surface combatants with the Torpedo Recognition and Alertment Functional Segment (TRAFS). By 2003, all aegis-class warships and several others will have it. The system uses the existing towed and hull-mounted sonars, along with powerful computers and software, to detect incoming torpedoes. Eventually, the detection system will be linked to a yet-to-be-invented counter-torpedo system. TRAFS was developed from the Northrop Grumman SLX-1 Multi-Sensor Torpedo Recognition and Alertment Processor.--Stephen V Cole