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Mar 5 17 2:07 AM
What's different is traffic (and possibly also number of ports, but I don't have comparative data).
'x' ships per day everyday between 'y' nr of ports will necessitate 'z' days of delay until convoy is formed and 'k' number of escort ships for the duration 't' of the journey . If I understand your messages, you consider k=1 as better then no k at all. Of course that's correct.Question is: can k=1 for all 'x' out there , in the historical circumstances ?
Mar 5 17 9:02 AM
Mar 5 17 11:06 AM
Mar 5 17 11:46 AM
Mar 5 17 12:42 PM
Grove, Eric J.
Published by Ashgate., Aldershot (1998)
ISBN 10: 1859284035 ISBN 13: 9781859284032
Quantity Available: 1
From: Parveen Papers (Bradford., United Kingdom)
Destination, Rates & Speeds
Item Description: Ashgate., Aldershot, 1998. Cloth. Book Condition: Very Good. No Jacket. Reprint. lxvi, xiv, 380, xiv + 50pp of maps, plans and tables. This is a revised edition of The Naval Staff History published 1957. Almost as new, errat slip is present. 1.2kg. Size: 8vo - over 7¾" - 9¾" tall. Bookseller Inventory # 006687
b) a very important aspect is convoy speed. With 1 fast cargo ship moving independntly at 16kts, chances of Uboat itnerception are "x". With 1 convoy , tipically going at 9kts, and including the above-mentioned fast cargo ship (forced to move at 9kts as well...), chances of Uboat interception are "y".Almost always y > x. (Convoying disadvantages the faster ships).
Mar 5 17 2:16 PM
Mar 5 17 4:18 PM
Mar 5 17 4:48 PM
Mar 5 17 5:06 PM
Mar 5 17 6:15 PM
The Admiralty's problem was that the USN had no excuses for their inaction. They had been intimately involved in developing all these concepts and lessons in 1917-18, received all the RN's TH on these subjects (per references in my prior post), and had even applied all these lessons off the US east coast before in 1918 against the German U-cruisers!
What convoy did was to vastly reduce target density for the U-boats.If I have 100 merchant ships, and each can be see from 15nm away by a surfaced U-boat sitting in a patrol line or in a choke point, then the visibility of the ship is about 710nm2. 100 such ships, one after the other down a routeing system, therefore have a sighting area of about 71000nm2. Put these into two 50 ship convoys and the total 'sighting area' is about 1800nm2, or about 2.5% of the sighting area for all the independents. This is why convoys work, by emptying the ocean of targets
Mar 5 17 6:28 PM
Thanks for another informed and well intentioned reply,
The grouping of ships to reduce overall sighting probability would work in a war where the enemy searches, finds, and attacks said ships by chance (random). That was not the case, as Uboat searches, contacts and attacks were highly organized.
With your permission, I would submit several attachments print-screened from "OIG Report. 68: the Role ot Decryrption Intelligence in the Operational Phase ot the Battle ot the Atlantic", dated April 1953, declassified in 2013.
The report analyses the effectiveness of German xB-Dienst decrypting capabilities between July1942 - Nov 1944, (thereby NOT covering our intended period of Jan to April 1942 (first 4 months of Drumbeat, without coastal convoys)), it's dissemination of messages to Uboats attacking trans-Atlantic convoys (coastal convoys not covered) , and the overall efficiency of Uboats "contacting" 2 categories of convoys: 1) category of convoys "compromised" by xB-Dienst (meaning with positions plotted and disseminated) 2) category of convoys "not compromised" by xB-Dienst (meaning found or not found through the search pattern assigned for the Uboats). The report does NOT evaluate the possibility of UBoats avoiding convoys, as the trans-atlantic battle was almost entirely done with convoys in the studied period.
Mar 5 17 6:32 PM
Mar 5 17 6:54 PM
Also, none of the Type XIV "Milchkuhe" were in operational service yet; all in training or still under construction.
Mar 5 17 6:57 PM
Actually what we're discussing is the U boats avoiding convoys as that's exactly what they did by switching the emphasis to unconvoyed ships off the US coast simply because they were a lot easier to sink, even given the reduced effectiveness due to range. Of at least the U boat commanders seem to have decided that. It was only when those routes were also protected that they switched back to the more important Atlantic convoy routes.
Mar 5 17 7:16 PM
Mar 5 17 7:24 PM
Mar 5 17 7:28 PM
ChrisPat wrote:Which means they were using SigInt to find individual ships so the code breaking did not uniquely disadvantage convoys. Being able to sink a limited number of targets in a given time begs for more targets than that to arrive at once, not spread out. Basic herd behaviour, bomber streaming, etc.
Mar 5 17 7:31 PM
Mar 5 17 7:36 PM
Mar 5 17 7:46 PM
ChrisPat wrote:If Drumbeat benefited early on from SigInt that SigInt must have led U boats into place to target individual ships; there were no convoys. Same detail as before, twenty four ships at once each day are going to lose fewer to U boats than one per hour if the U boat is given their positions and courses.
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