The "workhorse" industrial buildings of Pier 70 are dozens of structures built using corrugated iron or galvanized steel sheeting over skeletons of steel or wood. Though this kind of construction had been practiced since the end of the 19th century, most of these buildings were built to meet the intense shipbuilding needs of World War II, and many were demolished after active shipbuilding ceased. One older example that remains is the electrical substation and utility structure called Building 21, dating from 1900.

Though they may lack the architectural distinction of more permanent structures, these buildings were extremely important in the success of the shipyard's mission. They also have an integrity of design that signifies serious, pragmatic purpose.