A 1940 war gives Britain an escort advantage

How would a September 1940 start to the Second World War affect the naval balance?

Britain could have roughly sixty more escorts in service, while German peacetime submarine production would grow much less, creating a major anti-submarine advantage for the Royal Navy.

A September 1940 outbreak could put roughly sixty additional British escorts into service. German submarine production under another year of peacetime conditions would not rise at the same rate, while British anti-submarine construction was already positioned to expand sharply. Mobilization timing would therefore change the balance between U-boats and the smaller ships needed to contain them. The estimate concerns a counterfactual year of continued peacetime production, rather than a claim about the historical force in September 1939.