Abstract: The interface between a vessel loading crane and a container handling yard has been discovered to be the ideal location for the maintenance of a work bank of containers in conveyance along a one-way, reversible conveyance path. The conveyance path communicates to a vessel loading crane at one end of the path and apparatus for distributing and classifying the containers in the yard at the other end, this apparatus being preferably a bridge crane. Accordingly, a conveyor comprising an overlying support and an underlying shuttle car is disclosed. A shuttle car commutes reversibly along a shuttle car railway under containers supported on the overlying support. The shuttle car is operable to selectively raise containers above the support and move containers on the support reversibly and serially between work stations at either end of the conveyor.