Could an 80,000-ton battleship exceed Panamax?

Must the proposed 80,000-ton American fast battleship adhere to Panamax dimensions?

No; the exercise assumes the intended expanded locks associated with Montana planning, allowing a beam wider than Iowa's.

The American design exercise permits the additional beam associated with the intended expanded Panama Canal locks. Those locks are linked to plans for accommodating the Montana class. The proposed battleship can therefore be wider than Iowa instead of squeezing 80,000 tons into the existing Panamax limits. Its permissible dimensions depend on the shore infrastructure assumed in the scenario.