Supports

Down the centre of the hold march a line of deck support columns. This picture suffers greatly from being a flash pic taken in near-darkness, but if you look hard you will see a 2nd colum behind the first one. Every other column in the line is offset laterally, so that long planks could be run between the two lines of columns to subdivide the cavernous space and reduce cargo shifting. The shifting of tons of loose cargo in a heavy sea could be disastrous, resulting in complete capsize.