PURPOSE: To enable a work efficiency to be augmented by configurating a device in such a manner that a sediment carrying vessel is inducted into a water pool which is formed at the center of a dredging barge that has a U-shape configuration in cross section so that the sediment carrying vessel may dispose of the sediment into the bottom of the barge allowing it to be directly disposed from the bottom to a spoil bank by means of conveyors.

CONSTITUTION: A dredging barge 3 which has a U-shape configuration in cross section, is composed of its right and left float hulls 3a, and ship bottom floating fulls 3b. The dredging barge is allowed to be afloat with moorings 11 anchored at the sea floor by means of an anchore cable 12 so that a sediment carrying vessel may be inducted into a water pool which is formed in the lower section of the U-shape configuration in cross section. A motor is arranged in the dredging barge 3 to drive conveyors 4 and 5 independently. Under these circumstance, the sediment carrying vessel 2 disposes the sediment quickly into the dredging barge 3, then, the empty vessel leaves the barge for a next dredging point. In turn, the dredging barge 3 unloads the sediment accumulated on the bottom onto a spoil bank 7 by means of conveyors 4 and 5. Thus, this configuration enables the sediment carrying vessel to dispose of the sediment directly by opening its ship's bottom allowing a work efficiency to be augmented.