This may sound
surprising unless one things that the stowage exercise involves something like
five loading ports in Asia and an equal number of unloading (and loading) ports
in Europe; the need to minimize rehandles taking the full rotation into account;
considering ship bay allocations by alliance members; proper positioning of
dangerous, reefer and oversized containers; loading the ship evenly in view of
the small clearance between a large ship’s keel and the seabed at berth; to the
extent possible, reducing the metacenter of the ship by stowing heavy
containers as low as possible.
All this is done not
only by taking the full rotation into account, but also the plans of the yard
planners. These have similar problems to solve, trying to minimize both rehandles
(a nightmare in ports like Hong Kong where one must store containers 7-high),
as well as the movement of terminal equipment (cranes; chassis; straddle
carriers; reach stackers; AGVs, etc.). Recently, minimization of equipment
movements has one more objective to fulfill: environmental emissions.
Finally, the equation
may need to include gate operations, regarding the arrival of export containers.
Here, external tracks should interfere as little as possible with the movements
of terminal equipment which, btw, should be available and ready to serve them:
a synchronization issue. Thus, external tracks should wait as little as
possible and be given priority if they must pick up an import container on
their way out (known as ‘dual transaction’).
