A locking mechanism is provided for a tarping system having a flexible cover carried by a deployment mechanism having a horizontal arm spanning the width of a container, the deployment mechanism movable to an extended position in which the horizontal arm is adjacent one end of the container. The locking mechanism includes at least one locking element associated with one end of the container and at least one latching element having a latching portion configured to engage the at least one locking element. The latching element is pivotably supported on the horizontal arm so that that latching element can pivot to and from a locked position in which the latching portion engages the at least one locking element. A tension element is connected between the latching element and the cover to control the pivoting of the latching element under the force of gravity based on the position of the flexible cover.