| |
|
| BP |
Bletchley Park |
| Q SHIP |
"Q" ship - a heavily armed ship disguised as a merchant |
| R/V |
Rendezvous |
| WU |
Working up |
| WW |
Weather report |
| WWA |
Meteorological position derived from intercept of a U-boat weather report |
| Z |
Information derived from decryption of enemy W/T |
| |
|
| EX |
Sailed from (example EXL 20 means sailed from Lorient on the 20th) |
| AD |
Arrived at (example ADL 20 means arrived Lorient on the 20th) |
| |
|
| Ports/Status |
Used in conjunction with EX or AD above or in situation reports |
| |
|
| N |
Narvik |
| T |
Trondheim |
| B |
Bergen |
| |
|
| NO |
Starting 6 June 1944 - Operational as member of Arctic force |
| NT |
Starting 6 June 1944 - Transient in Norway either as potential member of Arctic operational force or for future transfer to Atlantic |
| |
|
| XXXM |
Where XXX is the trigram or bigram for the boat - Operating in the Mediterranean (for example U-371M) |
| M |
Total number of U-boats in the Mediterranean |
| MS |
Mediterranean at sea |
| MP |
Mediterranean in port |
| MT |
Toulon (sometimes just T is used when referring to M U-boat) |
| |
|
| W |
Working-up |
| SC |
Schoolboat |
| S |
Kiel |
| D |
Possibly Danzig |
| XS |
Christiansand South |
| R |
A point south end of belts (where the Baltic drains into the Kattegat) |
| |
|
| UX |
Black Sea |
| |
|
| U |
Brest |
| L |
Lorient |
| ST |
St. Nazaire |
| P |
La Pallice |
| G |
Bordeaux |
| F |
Unknown Biscay port |
| BE |
Boulogne |
| HE |
Havre |
| |
|
| MD |
Mediterranean doubtful |
| AD |
Atlantic doubtful |
| |
|
| OB |
Total operating in the Baltic (cancelled January 1944 U-boats reallocated to categories PW and SR) |
| OE |
Total operating in the Atlantic east of 26 West |
| ON |
Total operating in the Arctic (After July 1943 includes North Sea east of longitude of Shetlands) (Cancelled 6 June 1944 - replaced by NO and NT - see above) |
| OW |
Operating in the Atlantic west of 26 West |
| BP |
From October 1944 - U-boats in Baltic ports which were recently operating in either the Atlantic or Baltic |
| |
|
| PO |
Paid Off |
| PW |
Probably withdrawn from service |
| SR |
Short-range U-boats of 250 and 300 tons potentially operational in near waters |
| F |
After February 1944, Ex Italian submarines |
| |
|
| J |
Japanese territory such as Penang |
| |
|
| NI |
Not Identified |
| Q |
Liquidated (sunk) |
| D |
Doubtful (validity of bigram suspect) |
| |
| Commands Mentioned in Serial Messages |
| B.A.D. |
British Admiralty Directorate (this was the British liaison office in Washington D.C. |
| He who shall not be named |
The command to whom all the missing Admiralty serial messages are sent and whose name never appears in any of the serial messages is the Canadian Operational Intelligence Centre in Ottawa, Canada. This center was the Canadian counterpart the the Admiralty and COMINCH OICs and operated with knowledge of "Z" information. |
| |
| Tracking inputs |
| |
| The key to the success of U-boat tracking in the OICs was the use of intelligence from multiple sources to forecast the movements of the enemy. Some of the sources of information used by the OICs are listed below: |
| |
| Interception and deciphering of enemy signals |
When available this was the best source of information but there were periods where it was not available and there was always a delay in intercepting a message and delivery of a decrypted and translated version to the OICs. |
| |
|
| Volume and pattern of enemy signals |
Even when enemy signals could not be decyphered or DFed valuable information could be gleaned from the volume and pattern of signals |
| |
|
| Photographic reconnaissance |
The Allies conducted regular overflights of German U-boat bases and construction yards |
| |
|
| D/F |
Direction Finding - The Allies maintained an extensive network of direction finding stations and the majority of U-boat transmissions were intercepted by multiple stations and fixes generated. A good fix was within 40 or 50 miles a great fix was within 10 or 15 miles. |
| |
|
| TINA |
Op-20-G maintained oscillograph readings of German transmissions known as TINA. Individual radio operators touched the Morse key differently when transmitting. Op-20-G analysts could usually identify an enemy vessel by using TINA to fingerprint and track individual radio operators |
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|
| Radar |
Reports received from operational forces |
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|
| Visual sightings |
By ship or aircraft crews |
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|
| Agents |
Agents in German ports might report arrivals, departures or the maintenance in progress |
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|
| POW interrogation |
Information from preliminary interrogation reports was especially important to the OICs but the "Other U-boats" and "U-boat Bases" section of Final Interrogation reports provided an important source of information on personnel changes and on the capacity of U-boat bases. |
| |
|
| POW mail |
Incoming and outgoing mail from POWs was screened and censored if need be. On occasion POWs used code to transmit information such as the sinking or cause of loss of a U-boat. |
| |
|
| Enemy communiqués and press |
The Allied intelligence services monitored official communiqués issued by the German Armed Forces and studied press reports carefully. |
| |
|
| Diplomatic personnel |
Naval Attaches and other diplomatic personnel reported information such as the arrival of a U-boat in a neutral port. |
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|
| Friendly and neutral neutral observers |
Reports were received of U-boat sightings |
| |
|
| Survivors of U-boat attacks |
Merchantmen were questioned about the identity of the U-boat involved and the time and location of the sinking. |
| |
|
| Captured documents |
From captured ships and U-boats and taken from POWs |
