Heavier marine containers should be loaded first into ships at container terminals so that ship stability can be maintained during transport. It is helpful for the container terminals if lighter containers arrive earl...Heavier marine containers should be loaded first into ships at container terminals so that ship stability can be maintained during transport. It is helpful for the container terminals if lighter containers arrive earlier than heavier containers, because the latter can be stacked on the former. Therefore, the heavier ones can be loaded into the ships first. Shippers of marine containers do not, however, care for the matters of ships. They follow their own time schedules of supply chains sending marine containers with no relation to container weight. In addition to the conflict explained above, a ship must accommodate numerous containers sent by many shippers. Consequently, marshalling containers at container terminals before loading them into ships is necessary, although it causes inefficiencies of time and cost of cargo handling. This paper presents a proposal of a simple sequence of stacking marine containers at container terminals, adapting to random arrival of the containers irrespective of their weight, but it naturally keeps heavier containers stacked higher together with the stacking space minimized. An algorithm related to this proposal is the following： First, weight-ranked stacking addresses are assigned initially in a block of space at a container terminal; Second, containers are accepted and stacked up in the first block as they arrive at the terminal; Third, a lighter ranked address is sought for the next container if the number of containers on the initially assigned address for the container has already reached the maximum, which depends on the height of cargo handling equipment such as transfer cranes; Fourth, such containers are stacked up on the lighter ranked address. The address is reassigned with the weight rank of the container; Fifth, a heavier ranked address is sought for the next container if no lighter ranked address can be found; Sixth, such containers are stacked up on the heavier ranked address; Seventh, change the block to the next one if either a lighter or heavier ranked address cannot be found; Eighth, repeat the sequence above. This paper demonstrates the algorithm run by a simulation model for which actual arrival records of marine containers to a container terminal of Port of Yokohama are applied. Six ships of different sailing routes are analyzed using the simulation model. All analysis results show that heavier containers are stacked higher with a minimum number of blocks. Therefore, no marshalling of containers is necessary for loading the containers into ships.展开更多
文摘Heavier marine containers should be loaded first into ships at container terminals so that ship stability can be maintained during transport. It is helpful for the container terminals if lighter containers arrive earlier than heavier containers, because the latter can be stacked on the former. Therefore, the heavier ones can be loaded into the ships first. Shippers of marine containers do not, however, care for the matters of ships. They follow their own time schedules of supply chains sending marine containers with no relation to container weight. In addition to the conflict explained above, a ship must accommodate numerous containers sent by many shippers. Consequently, marshalling containers at container terminals before loading them into ships is necessary, although it causes inefficiencies of time and cost of cargo handling. This paper presents a proposal of a simple sequence of stacking marine containers at container terminals, adapting to random arrival of the containers irrespective of their weight, but it naturally keeps heavier containers stacked higher together with the stacking space minimized. An algorithm related to this proposal is the following： First, weight-ranked stacking addresses are assigned initially in a block of space at a container terminal; Second, containers are accepted and stacked up in the first block as they arrive at the terminal; Third, a lighter ranked address is sought for the next container if the number of containers on the initially assigned address for the container has already reached the maximum, which depends on the height of cargo handling equipment such as transfer cranes; Fourth, such containers are stacked up on the lighter ranked address. The address is reassigned with the weight rank of the container; Fifth, a heavier ranked address is sought for the next container if no lighter ranked address can be found; Sixth, such containers are stacked up on the heavier ranked address; Seventh, change the block to the next one if either a lighter or heavier ranked address cannot be found; Eighth, repeat the sequence above. This paper demonstrates the algorithm run by a simulation model for which actual arrival records of marine containers to a container terminal of Port of Yokohama are applied. Six ships of different sailing routes are analyzed using the simulation model. All analysis results show that heavier containers are stacked higher with a minimum number of blocks. Therefore, no marshalling of containers is necessary for loading the containers into ships.
