Um... Isn't this what I wrote in my last post?
Antisocrates,
Yes it is. It isn't what you wrote in your OP however.
Turning to your modified POD now, Lloyd George's postwar lies aside, the Admiralty knew perfectly well that convoys were needed and they knew that very soon after the first bout of USW.
However, just like Ernie King in early 1942, the Admiralty didn't have the assets to set up all the convoys that were needed. The Grand Fleet at Scapa and Rosyth, plus the other naval operations ranging from the Channel to the Med, all required destroyers in large numbers. There were simply none to be had, so something would have to give.
If shipping losses grew great enough, Britain would simply bite the bullet and remove the necessary destroyers and other escorts from someplace. We could see the Harwich Force disbanded, the aggressive patrolling in the North Sea curtailed, and the Grand Fleet learning to live with less. Jellicoe would scream, as he in did in the OTL, but, again like in the OTL when at the Admiralty he planned similar measures in 1917, Jellicoe will go along with it.
We may even see something similar to the WW2 destroyers for bases deal between the US and UK or more concessions to Japan in return for her sending additional naval to Europe. (The IJN provided some convoy escorts for the Med in the OLT.)
We'll see a race between convoy creation and sinking rates. The RN needn't have ASDIC or depth charges for the convoys to be successful. It's simple mathematics, by greatly reducing the number of sailings, you greatly reduce the number of potential intercepts. All the RN escorts need do is force the submarines to dive and stay underwater as the convoy passes. With their low underwater speeds, the subs will have less of a chance to reach a firing position and, if they surface to attempt an end around, they place themselves in the sights of the escorts.
USW in 1915 could prevent the Entente offensives of '15 and '16 by limiting shell production. While the Entente could still defend themselves, how Germany uses this "lull" is open to question.
Bill