Shipping. Amount Required to Sustain a German Invasion of the British Isles. Report by J.I.C. Covering Minute by Prime Minister Dated 20.7.40

13. In the case of 'A' above, the number of ships of between 1,500 and 5,000 tone which would be required by the Germans amounts to a total of 430. 450. In the case of B above, this figure would amount to 14. It may be concluded therefore that actual shipping required for an invasion would not be a limiting factor. D. THE DAILY TARGET PRESENTED TO BRITISH NAVAL AND AIR ACTION SHOULD THE GERMANS ATTEMPT TO MAINTAIN A FORCE OF 150,000 TROOPS IN THE UNITED KINGDOM BY A FERRY SERVICE. 15. It was concluded, vide paragraph 10, that, allowing for 25% casualties, a total of 50 ships, involving a total of 100 round trips per month would be required.