By the late 1960s, upwards of 70% of the trade between the U.S. and Europe was containerized with the remaining percentage better suited to other cargo handling methods.  In an effort to remain competitive with SeaLand, United States Lines, and a growing number of other carriers, New York-headquartered Moore-McCormick Lines’ ordered four new, fast combination roll-on/roll- off containerships “Sea-Bridge”-class vessels…