PURPOSE: To improve an installation means for a triangular plate for preventing the stay of ores, etc., on an upper deck part of the curved corner part of a hatch opening, in the handling a loading cargo such as ore.

CONSTITUTION: An upper deck part in the vicinity of the curved corner edge 4a of a hatch opened port of an upper deck 4 is covered aslantly by a triangular plate 8, and only one side (c) of the triangular plate 8 is welded to a hatch end coaming 1. Further, the triangulat plate 8 is supported also on a supporting member consisting of the U-shaped metalwares 7a and 7b installed on the hatch end coaming 1, bolts 5a and 5b, and nuts 6a and 6b. Accordingly, the inflow into the triangular plate 8 of the longitudinal bending stress for a hull is prevented, and the generation of the crack at the welded part of the triangular plate 8 is prevented.