Redoutable patrol submarines: range, speed and armament

The 31 Redoutable boats formed a substantial ocean-going submarine force. Their stated specifications include about 1,500 tons surfaced displacement, 20 knots on the surface and a 14,000-nautical-mile surface range at seven knots. Their surface speed is linked to the ability to pass in and out of Gibraltar. The listed armament combines nine 550 mm torpedo tubes, two smaller 400 mm tubes and a 100 mm deck gun. France maintained its emphasis on patrol submarines through the Washington and London treaty periods.