I posted a comment about framework showing through hull plating on Edson's recent photo of the Columbia Star.Malcolm's photo (Dec 21 1975) with her gangway down shows really visible framework.Would be grateful if someone could explain how this happens and why some vessels show this while others,even older, there is no sign.Looks a bit alarming to me !

I did not know that any of these still existed as late as 1975. First designed and built during WW-I, they used to call this type of cargo ship a "Laker" because most of them are constructed in shipyards in the Great Lakes. The most famous one was the ship used in the 1933 movie, "King Kong". In addition, the first US ship sunk by the Japanese on 7 December 1941, the Cynthia Olson, which was sunk by the Japanese Submarine I-26, was one of these.