In Reply to: Over a barrel posted by David FG on July 05, 2009 at 17:42:
: : What is the origin of phrase "to be over a barrel?"
: : Thank you for this wonderful service.
: Apparently it is of American origin, and the most likely derivation comes from a form of punishment, or humiliation, involving binding someone's hands and feet and rolling them over a barrel.
: A person in that situation is completely at the mercy of his captors/tormentors and thus is had 'over a barrel'.
According to my references (and http://www.phrases.org.uk/meanings/over-a-barrel.html on this site) it refers to a method of forcing water out of a near drowning victim's lungs.