Bechtel, a San Francisco-based company, is involved in massive projects around the globe, from building artificial oil-drilling islands in the Caspian Sea and airport terminals in Peru, to renovating London's venerable Underground. It has 42,000 employees and sales in excess of $16 billion. Based on revenue, it should be in the upper echelons of the Fortune 500 elite. It is not because it is a private, very private, company founded four generations ago by Warren A. Bechtel and now headed by Warren's great-grandson. Warren was brash and bold, a large man with a commanding presence and even larger dreams. He was born Sept. 12, 1872, in Freeport, Ill., but grew up in Peabody, Kan. As a teenager, Warren was bored and restless. Music was his passion, the slide trombone his companion. After graduating from high school, the 19-year-old joined a largely female dance band dubbed the Ladies Band. His parents were mortified.