Ship operation management system

A ship operation management system comprising:

• a liquefied natural gas (LNG) carrier which uses a natural gas generated by vaporization of LNG, as propulsive fuel, the LNG carrier including a cargo tank which stores the LNG therein, a spray apparatus which performs spraying operations for spraying the LNG to an inner surface of the cargo tank, and a carrier communication device;
• and
• land-based equipment including a land-based communication device which is capable of communicating with the carrier communication device, and a processing device,
• wherein the processing device includes:
• a first vapor quantity estimating section which estimates a total quantity of a natural vapor generated from the LNG remaining in the cargo tank in a case where the LNG carrier is traveling on a planned ballast course, based on sea weather data;
• a second vapor quantity estimating section which estimates a total quantity of a spray vapor generated by performing the spraying operations in a case where the LNG carrier is traveling on the planned ballast course, based on the sea weather data;
• and
• a heel quantity calculating section which calculates a required heel quantity, by adding up the total quantity of the natural vapor which is estimated by the first vapor quantity estimating section and the total quantity of the spray vapor which is estimated by the second vapor quantity estimating section,
• wherein the land-based communication device transmits the required heel quantity to the carrier communication device, while the LNG carrier is on a laden voyage.