Article 6: measuring a warship without fuel

The treaty's standard-displacement system counts a fully manned and equipped vessel while excluding fuel, lubricating oil, fresh water, and ballast water. That produces a comparison condition rather than a seaworthy load, and Article 6 expressly extends it to submarines. The article also defines its ton as 2,240 pounds, equivalent to 1,016 kilograms. Counting fuel would penalise navies whose ships needed greater range because their likely theatres were larger. A French-Italian contest in the Mediterranean was a short-range prospect, whereas British, American, or Japanese forces might have to cross oceans. The measurement rule itself embodied assumptions about geography, range, and fair comparison.