Article 7 generally bars submarines above 2,000 standard tons, or 2,032 metric tons, and guns above 5.1 inches, or 130 millimetres. Each signatory may nevertheless retain, build, or acquire up to three submarines as large as 2,800 standard tons, or 2,845 metric tons, with guns up to 6.1 inches or 155 millimetres. France receives a special allowance for one already-launched 2,880-standard-ton boat with 8-inch guns, while existing smaller boats with heavier guns also receive a retention clause. The displacement ceiling may do little to restrict oceanic range because standard displacement excludes fuel. The headline limit sat alongside carefully bounded exceptions and a significant endurance caveat.
Chapter · 23:19-25:20
Article 7 caps submarines but preserves exceptions
Article 7 sets a 2,000-ton and 5.1-inch baseline for submarines while allowing a few larger boats and a special French exception.