1. ( subj-compl with бытье, стоять etc
subj: паровоз, пароход)) (a locomotive or ship is) ready to set out (upon some course)
X стоял - = X was under steam
X had steam up.
2. substand ( adv or subj-compl with бытье (subj: human) in a drunken state (more often a slightly drunken one)
X был под парами - X was (a little) fuzzy (tipsy, high, tight)
X had had a few.Большой русско-английский фразеологический словарь. — М.: ACT-ПРЕСС КНИГА. С.И. Лубенская. 2004.