PURPOSE: To secure such a cargo oil transferring structure as excellent in safety, labor savability and economical efficiency by making a stop valve additionally installed in a side wall upper part of a lower cargo oil tank, partitioned from an upper cargo oil tank by a horizontal bulkhead, possible to be opened or closed by means of remote control from the outside of the lower cargo oil tank.

CONSTITUTION: Each double ship side structure 02 is installed at both sides of a cargo oil tank 01, while there is provided a horizontal bulkhead 04 which partitions off the cargo oil tank 01 into an upper cargo oil tank 02 and a lower cargo oil tank 03, and in the shallowest draft state at time of operating a tanker after loading cargo oil in the tank 01, the horizontal bulkhead 04 is set up more downward than a cargo oil level where pressure acting on a ship bottom 05 and pressure in sea-water acting on this bottom 5 becomes equalized. A through piece 1 is installed in a side wall 06 of the lower cargo oil tank 03, and a stop valve 2 capable of doing remote control from the outside of the lower cargo oil tank 03 is installed in the one end of the piece 1. If the stop valve 2 is opened when a broken hole 3 has occurred in the bottom 05 of the lower cargo oil tank 03, the cargo oil in the lower cargo oil tank 03 is automatically transferred into a ship side noncargo oil tank of the double ship side structure 02 as shown in an arrow 4.