A commercial unit of volume equal to exactly 5 cubic feet or 0.141 584 cubic meters. There are exactly 8 barrels bulk in a freight ton and 20 in a register ton
Russ Rowlett (Director), How Many? A Dictionary of Units of Measurement, Center for Mathematics and Science Education University of North Carolina, USA 2005. http://www.unc.edu/~rowlett/units/dictA.html, (Unit of Meas and Covr Factors - Amer) {608}