A heuristic is developed to plan loads for containerized cargo ships. It is designed to serve a port which uses gantry cranes (transtainers) and trucks to handle containers. The model recognizes constraints on ship stability, placing containers in a bay with the proper length, placing refrigerated cargo near electrical outlets, limits on stack height in under deck bays, limits on stack weight in on deck bays, and the need for support under a container. Provisions are made for the operator to handle overstowage of cargo for different ports, placement of hazardous cargo, and placement of oversize cargo. The model uses minimization of transtainer movement time and minimization of rehandles in the yard as an objective. The heuristic uses strategies for container placement similar to those used in manual load planning. A test of two ships and four voyages at the Port of Portland produced feasible load plans for each voyage. Transtainer movement and rehandling time varied for the four voyages, but on average the heuristic reduced a composite material handling measure by 4.8%. Time required for load planning should be substantially reduced using the heuristic
