Replacement rules that keep shipyards working

The alternative treaty permits each signatory to keep at most one fifth of its capital-ship tonnage under construction, with permission to build up to its fleet limit from 1922. Ships laid down before 1914 with guns of 14 inches or less become eligible for replacement in 1926; pre-1914 ships with larger guns follow in 1930. Ships laid down during 1914-1918 become eligible in 1934, and those laid down during 1919-1922 follow in 1936. Treaty-era ships must complete 18 years of service before replacement. This schedule would keep Japanese construction moving at roughly one ship a year, with some gaps. Even the proposed eight-ship French and Italian fleets could support nearly continuous work at one construction yard, with another yard maintaining the ships already in service. Predictable construction would also make each navy's replacement programme easier for the other signatories to monitor.