PURPOSE: To improve the unloading efficiency by providing a space cutting hoppers on one side of the connecting part of the hoppers to furnish an unloading device and raising the bottom part of the hoppers on the other side to provide passages of unloading conveyors for shortening the whole length of a captioned boat.

CONSTITUTION: Funnel-shaped hoppers 2 and 2 are connectively arranged in the center part of a bottom 1, and on one side of their connected part, a space 5 is cut out for furnishing an unloading device B consisting of a conveyor 6, a tower 7, a revolving boom 8, and others. Meanwhile, on the other side, bottom parts 12 and 12 of hoppers 2 and 2 are raised, and provided with passages 15 and 15 for unloading conveyors 14 and 14, which are connected to take over conveyors 13 and 13 arranged under slide gates 11... opened on both sides in the longitudinal direction of bottoms 10 and 10 of hoppers 2 and 2.