Abstract: The invention is directed to a method and apparatus for covering open-top truck trailers used to haul wood chips and the like. A flexible cover is pulled over the open top of a trailer via a shaft rotatable between a first and second position; a projection extending from the shaft and configured to engage the flexible cover when the shaft is in a first position and to disengage the flexible cover when the shaft is in a second position; and a counterweight extending from said shaft and configured to rotate the shaft from a second position to a first position.