Some R.P.I. grads
Else clues• Chang's twin's
• Locomotives
• Locomotives: Abbr
• M.I.T. grads
• M.I.T. grads: Abbr.
• Machines: Abbr.
• Many BS holders
• Many Caltech grads: Abbr.
• Many M.I.T. grads
• Physics pros, often: abbr.
• Road designers, e.g.: Abbr.
• Some B.S. holders
• Some M.I.T. grads
• Some M.I.T. grads: Abbr.
• Some MIT grads, briefly
• Some specialize in elec.