General Dynamics, one of the Pentagon's major submarine builders, yesterday announced that John Welch, chief of its Electric Boat business unit, had been promoted to senior vice president and head of the Marine Systems Group. Welch had been a vice president of GD and president of Groton, CT-based Electric Boat since October 1995, according to a company statement. He joined Electric Boat in June 1989 as its vice president for program development. In addition to having served as program manager...