A hypothetical fourth twin mount would give the Sumner eight main guns, a sixty-percent increase over the Fletcher's five. Accommodating it would probably require sacrificing light antiaircraft weapons or lengthening the hull. Either choice would move the design beyond the intended modest increase over a Fletcher. The stated construction costs are $8 million for a Sumner and $6 million for a Fletcher. The additional $2 million is judged worthwhile for the actual design's extra capability. The eight-gun version remains a speculative alternative.
Notable Point · 33:27-34:19
A fourth twin mount would change the Sumner's compromises
An eight-gun Sumner would probably sacrifice light AA or need a longer hull, while the actual design already cost $2 million more than a Fletcher.