Abstract: An improved locking mechanism for securing cargo units and the like during transport has first and second complementary locking pawls carrying oppositely directed locking dogs, each pawl being pivotally mounted between spaced side supports for movement from a retracted position to a generally upright locked position. While the first pawl only is biased by spring means towards an upright position, it is held down in a retracted position by retaining portions of the second pawl. As the second pawl is lifted from the retracted position to the generally upright position, its retaining portions disengage from the first pawl permitting the first pawl to pivot upwardly to the generally upright position under the urging of the spring means simultaneously causing both the first and second pawls to move into mutually locking engagement. The spring means biasing the first pawl only is located in a sheltered non-exposed out-of-the way position between the spaced supports and below the upper edges of the spaced supports.