5 Stacking on ground and terminal operation with freight containers

5.1          The ground should be a firm, flat and drained surface. On the ground, the freight container should be supported by the four bottom container fittings only. When stacking freight containers, the bottom surfaces of the lower corner fittings of the upper freight container should have complete contact with upper surfaces of top container fittings of the lower freight container. A shift of up to 25 mm laterally and 38 mm longitudinally may be tolerated.

5.2          A freight container stack may be subject to forces by heavy wind. This might lead to sliding and toppling of freight containers. Stacks of empty freight containers will be more subject to such dangers than stacks of packed freight containers. The critical wind speed is higher for multiple rows than for a single row. Wind effect can be reduced by limiting the stacking height, by block stowage or by a combination of both. A recommended combination is shown in the table below:

5.3          Above recommendation is applicable for a wind speed up to 20 m/s (8 Bft). In case of higher wind speeds, additional measures should be considered, such as changing the block to a stepped pyramid or securing freight containers with lashings to the ground.

5.4          Freight containers should be moved within a terminal area only by use of suitable equipment, such as van carriers, reach stackers or trailers. Trailers should be so constructed that the freight containers are supported by their corner fittings. For operation within the designated terminal area, tie down devices are not required, provided that the freight container is correctly loaded on the trailer and prevented from moving horizontally. Therefore, trailers which are not equipped with twistlocks should be fitted with substantial corner plates or other restraints of sufficient height to retain the freight container in position.