PURPOSE: To shorten the length of an engine room and improve operability and facilities for maintenance by providing a space for auxiliary machinery in one part a cargo hold space adjoining to an engine room provided with a main engine.

CONSTITUTION: On the lowermost part of an ahead side cargo hold space 5 adjoiningly arranged to an engine room 3 provided with a main engine 4, a space for auxiliary machinery 9 is formed and the auxiliary machinery is arranged therein. An opening 10 is formed on the ceiling of the space 9 for auxiliary machinery and a closing door 11 is fitted. The engine room 3 and the space 9 for auxiliary machinery are communicated through an opening part 12 between. By this constitution, the length of the engine room can be shortened, and standardization of arrangement of auxiliary machinery is facilitated.