摘要:Tramper cargo handling at port is done on a first-come and first-served basis in most cases. A tramper has to voyage at high velocity to the port for early turn of cargo handling and after arrival waits for a long time for her turn to come. The act is inefficient and leads to severe increase of CO2 emission. Port reservation system can mitigate the problem. If ships can get the rights of loading at a future date, the ships can voyage to the destination port at slower speed. In this paper tramper transportation simulator is developed which can re-create demurrage distribution and estimate CO2 emission generated by ship. Firstly, basic port reservation system based on auction is estimated and that the reservation system favors smaller ships over bigger ships is revealed. Secondly, a modification of the reservation rule is introduced and it is shown that its effect is enough to mitigate the potential problem.