A first sidewall includes a pair of threaded bosses nesting within corresponding cavities in a second sidewall. Bolts extend through the cavities into threaded engagement with the bosses to secure the sidewalls with one another. One of the bosses supports a knurled or toothed wheel for engagement with a parachute cord. A pivotable pawl having a knurled or toothed surface is pivotably supported on a shaft anchored in the sidewalls and spring biased toward the wheel into engagement with the parachute cord to prevent translation of the parachute cord in one direction. The other boss supports a hook or cord for anchoring the tie down to an anchor.