And one thing here. You made the claim about the 200k tons already once. It is factually wrong. The sinkings in the last 5 months before USW was declared were on average 400k tons plus.
And the British amirality was absolutely desperate about the situation.
Based on a quick and dirty Wiki check it appears we are both wrong:
Assuming the military vessels don't broadly swing the numbers in the 5 months prior to USW being declared in Feb 1918 losses did indeed exceed the 200 kt I mentioned, averaging 323 kt. Greater than my estimate, less than yours. Assuming these numbers continue to slowly increase an average of 425 kt for the period between OTL USW being declared (Feb 1917) and Convoys really kicking in (November 1917) seems on the higher end of reasonable. In this case you get a total of 3.825 million tons compared to the 5.174 million of OTL. A savings of 1.349 million tons.
In 1917 The British completed 1.163 million tons of shipping within Britain. They also had orders for 81 "War Standard" ships in the US that were taken over by the US Merchant Marine in OTL, plus others for France. These, plus those built in Canada for both Britain and France, and the Allies total deficit in shipping from 1918 as compared to 1914 is probably reduced from around 6 million tons to around 4 million.
Artos stark that is based on the fact that 50% of the food that the UK was eating was imported. If you reduce that by 40% it comes to 20% less which was the level of the turnip winter.
All the other figures are based on actual imports.
Indeed, but there are a few suspect assumptions in this calculation:
1- You seem to be making a very suspect break between the US Entering the war and the US stopping all trade, usually with a comment about unsecured loans. As has been pointed out, the funds are there to negotiate for secured loans, negating this whole issue. Further, there was no injunction against the regular purchase of goods with American dollars, of which the Allies did have some reserve, and of which they can gain more by directly selling gold or securities, if they cannot obtain secured loans in American dollars
2- You seem to assume that all, or most, of the foodstuffs crossing the Atlantic came from the US. While certainly a large amount did, AIUI Canada was the main supplier of Wheat, The Caribbean was the primary source of Sugar, and Argentina was the primary source of meat products.
3- The US entry into the war actually hurt Britain's ability to import food as limited shipping was needed to transport American troops and equipment to Europe. This is part of the reason that rationing was actually introduced later in the war. ITTL that pressure is removed
4- You assume that Britain's home production is a fixed variable. In fact it is estimated that the caloric content of British home production increased by 24% by 1918. This number is possibly slightly inflated but the amount of home grown food did significantly increase. This goes hand-in hand with the introduction of rationing, which, as I mentioned earlier would actually probably help the British economy. These two measures together meant the caloric intake of the average Briton fell by only 3% during the war. So it is somewhat confusing to see the assertion that a war with
less losses to u-boats would lead to
greater starvation.
Yet wartime loans *were* defaulted on postwar, so evidently these weren't a safe investment. . So warning American ivestors against subscribing to unsecured loans was clearly the right call, whoever initiated it.
True, though it is actually more complicated than that. The Lausanne conference was an effort under American pressure for the suspension of reparations from Germany to the Entente powers. Since reparations had been used to make payments on US war debt the agreement to end reparations was contingent on reaching an agreement with the US over their debt. This was rejected by Congress, which led to the "Wave of defaults" that became a part of the story of the Great Depression. If it makes you fell any better, proportional to GDP more debt owed to the UK was defaulted in this period than was to the US. Approximately 17% of the US GDP's worth verses 28% of the UK GDP (
https://voxeu.org/article/sovereign-debt-relief-and-its-aftermath-1930s-1990s-future)
Julian, the convoy system was only possible due to US ships and ASW assets. Without that the inherent drop of 30% of the capacity inshippimg that comes with a convoy system would have been to hard to bear.
The US ships helped, certainly, but they were not actually critical to the existence of convoy. The Admiralty in early 1917 had estimated that they were 32 destroyers short on ships for convoy. This was based on three false assumptions:
1- They believed that destroyers would be needed far more than they ultimately were. Predreadnoughts, Armed merchant cruisers, sloops and Armoured Cruisers all ended up doing the job perfectly adequately in all but the most dangerous waters, and there were lots of destroyers to cover those even without those sent from the US. Particularly since the US 6th battle squadron required additional destroyers to screen for, deducting from the total available for convoy.
2. The Admiralty had been working with numbers of total sailings from British ports (300 per day), as the number that needed escorting, rather than from those crossing the Atlantic (140 per day)
3. The Admiralty assumed that they would need a 1:1 ratio of escorts to merchants. This would turn out to be way off. By October 1917 39 ships were sailing with the same number of escorts as had covered 12 in May.