After 12 years of your question not answered: These ships were 'hatch-less' container ships, as those racks went all the way down to the ship's double bottom,the containers being stacked from that bottom up to 4 tiers above the main deck. Because the holds had no hatches, rainwater (and seawater) had free access to the bottom of the holds. Therefore the ships were equipped with powerful pumps to drain that water overboard.

Good day. Question here: Why would some container ships have those racks for the containers and others not? By choice or due to the seas the ship may encounter. I'm sure those would surely hold them better together but I'm just asking to know. Thanks.