The belt tapered from 3.7 inches to one inch, while the barbettes had only 1.5 inches and the turrets ranged from 0.75 to 2.5 inches. Portholes help reveal how limited the belt was, and deck armor is absent from the figures given here. Wichita's turret armor reached eight inches, while the New Orleans class combined a three-to-five-inch belt with turret protection ranging from 1.5 to eight inches. The Portland class carried a stronger belt but retained relatively light turret armor, which still favored long-range engagement. These comparisons place the Northampton among reconnaissance ships that relied on distance and maneuver rather than protection in a cruiser duel.
Notable Point · 15:49-18:38
Thin protection kept the Northamptons at long range
Armor figures and comparisons with later US cruisers show why the Northamptons were expected to avoid a sustained gunfight.