Usually the marine terminal will then install a computer system to
replace the paper filing system. A computer system gives more people
access to the same data without the physical interference problems
associated with the paper system. The marine terminal can then continue
to add personnel to the tracking effort as the inventory and handling
The first computer system a marine terminal installs usually addresses
only the office needs and it is still separated from the yard handling
equipment in the marine terminal by a paper system. For instance,
work lists are entered into the computer by office personnel and
are printed out for the equipment operator to follow. In the automation
hierarchy, the office computer system is considered a Level-3. The
personnel operating the handling equipment are substitutes for the
Level-2 and Level-1 computers.
The Problem Evolves
Invariably the inventory recorded in the office computer and the
inventory actually in the yard are different. An error in the computer's
inventory will create an error on the work list. The error on the
work list will force the equipment operator to select a yard position
for a container different from the position on the work list. The
equipment operator will record the change on the paper work list
and after the list has been completed it will be returned to the
office. Office personnel will attempt to correct the inventory in
the computer from the corrected work list. Due to other inaccuracies
in the computer's inventory, a certain number of these corrections
will be rejected by the computer as inconsistent.
At this point the office personnel can usually ignore the inaccuracies
in the computer. As the volume of containers increases, however,
it is not unusual for an inventory system of this type to be as
much as 20% inaccurate. When the inaccuracies become intolerable,
the terminal operator has several methods to correct the problem:
- Routinely have yard personnel perform manual inventories of
either the entire facility or areas of the facility and enter
the inventory information into the computer system to bring it
up to date.
- Add mobile yard personnel to locate lost containers required
for immediate delivery to either a truck or a vessel; that is,
containers in positions different from the position recorded in
Both of these solutions continue to increase the amount of nonproductive
labor in the terminal. As the volume increases and as more ships are
processed, the handling equipment operators are more likely to shuffle
containers around at the end of each ship in order to get the ship
off berth. Eventually the manual inventories and the staffing required
to locate containers becomes inefficient and expensive. There are
two steps to correct this problem:
- Place computer CRT terminals in the handling equipment to reduce
the lag between the time a work list is given to the equipment
operator and the time it is entered and confirmed in the computer.
- In addition to installing CRT terminals, instrument the handling
equipment so that the machine can determine its location in the
marine terminal and report its position directly to the computer
without any human intervention.
The method selected will depend on the quality of the labor available
at the facility. If the labor quality is good, there is little economic
incentive for the higher cost step of instrumenting the handling equipment.
The CRT and instrumentation installed in the handling equipment is
usually connected to the Level-3 computer with some variation of a
radio system, although other methods have been successfully employed
For marine terminals installing a Level-3 computer system, the
following beneficial effects were reported by at least 50% of the
marine terminals responding to a recent survey [reference 5]:
- The dwell time for import containers is reduced.
- The necessary sorting, checking, and forwarding of documentation
- Overall administrative costs are lower.
- The available space in the container yard is used more efficiently.
- The turn round time for equivalent sized vessels is reduced.
- The average waiting time for vehicles to be serviced at the
import/export grid is reduced.
Productivity increases have been noted for advanced passive tracking
Level-3 computers in several other areas [reference 6]:
- vessel planning
- yard operation
Historically, vessel planning is a trial and error process. Once a
plan is made, it usually remains unchanged because of the burden of
paperwork associated with a new plan; the cargo center of gravity
must be recalculated and a new stow plan produced. If the computer
performs these functions, then the planner has the extra time and
the incentive to obtain the best possible loading on the vessel. In
addition, the planner can tune the center of gravity of the vessel
to reduce its fuel costs between ports.
When the handling equipment operator can receive the worklist
on a CRT, then it is much easier for planning personnel to change
the work list. This is usually critical in the final stages of ship
loading, when the plan changes must be given to the handling equipment
operator in a timely and accurate manner.
The most advanced realization of these two concepts are the color
graphic planning systems [reference 7-8]. In these systems, the
containers are drawn on a color CRT screen. The planner uses a pointing
tool to indicate which containers are to be moved and where they
should go. The computer then creates the work list and transmits
the list to the CRT in the handling equipment for execution.