Convertible tanks exploit treaty displacement rules

Henderson's institutional maneuvering appears in small technical details as well as major ship programs. Some carrier and cruiser feed-water tanks could be converted to carry fuel in wartime. Feed water did not count toward treaty standard displacement in the way fuel did, so the arrangement preserved legal peacetime measurements while reserving additional endurance. The example is a compact lesson in how naval architects and administrators could use dual-purpose spaces to reconcile formal limits with operational needs.