Dray Line

[W T. Gordon]

My brother, who lives in Albany, Georgia, put me on to the term 'dray line' for a group keeping warm by huddling around a fire in a steel drum.  Google.com gives me over 700 sites with 'dray line,' and while I have only checked the first 200 or so, I find exactly one with the term used in that sense (from the Albany Herald!)  How widespread is this usage? Does anyone have  documentation for the development of this sense of the term, apparently so far removed from its original and traditional meaning?
Terry Gordon