Convoy route OB
| Code | OB |
| Route | Liverpool - Outward (North America) |
| Area | North Atlantic |
| Notes | From September 1939 to July 1940 from Bristol Channel, then from North Channel. In July 1941 merged with ON(F) and ONS. |
| Convoys | Date | Losses |
| OB-4 | Sep 1939 | 1 ship sunk for a total of 4.060 tons |
| OB-17 | Oct 1939 | 1 ship sunk for a total of 5.202 tons |
| OB-25 | Oct 1939 | 1 ship sunk for a total of 5.317 tons |
| OB-46 | Dec 1939 | 1 ship sunk for a total of 8.795 tons |
| OB-48 | Dec 1939 | 2 ships sunk for a total of 14.065 tons |
| OB-71 | Jan 1940 | |
| OB-74 | Jan 1940 | 1 ship sunk for a total of 5.494 tons |
| OB-176 | Jul 1940 | 1 ship sunk for a total of 8.999 tons |
| OB-188 | Jul 1940 | 4 ships sunk for a total of 29.320 tons |
| OB-191 | Jul 1940 | 1 ship sunk for a total of 6.322 tons |
| OB-193 | Aug 1940 | 1 ship sunk for a total of 5.408 tons |
| OB-197 | Aug 1940 | 2 ships sunk for a total of 8.953 tons |
| OB-198 | Aug 1940 | 1 ship sunk for a total of 4.397 tons |
| OB-202 | Aug 1940 | 2 ships sunk for a total of 16.620 tons |
| OB-201 | Aug 1940 | 1 ship sunk for a total of 3.774 tons |
| OB-205 | Aug 1940 | 3 ships sunk for a total of 10.991 tons |
| OB-206 | Sep 1940 | 1 ship sunk for a total of 4.261 tons |
| OB-213 | Sep 1940 | 2 ships sunk for a total of 16.169 tons |
| OB-216 | Sep 1940 | 5 ships sunk for a total of 41.338 tons |
| OB-217 | Sep 1940 | 5 ships sunk for a total of 29.066 tons |
| OB-218 | Sep 1940 | 4 ships sunk for a total of 20.873 tons |
| OB-220 | Sep 1940 | 1 ship sunk for a total of 2.499 tons |
| OB-221 | Oct 1940 | 1 ship sunk for a total of 5.943 tons |
| OB-225 | Oct 1940 | 1 ship sunk for a total of 5.811 tons |
| OB-227 | Oct 1940 | 1 ship sunk for a total of 4.747 tons |
| OB-228 | Oct 1940 | 4 ships sunk for a total of 12.822 tons |
| OB-229 | Oct 1940 | 2 ships sunk for a total of 11.199 tons |
| OB-240 | Nov 1940 | 1 ship sunk for a total of 5.094 tons |
| OB-235 | Nov 1940 | 1 ship sunk for a total of 5.168 tons |
| OB-234 | Nov 1940 | 1 ship sunk for a total of 3.059 tons |
| OB-244 | Nov 1940 | 6 ships sunk for a total of 31.738 tons |
| OB-248 | Nov 1940 | 2 ships sunk for a total of 6.255 tons |
| OB-249 | Nov 1940 | 1 ship sunk for a total of 4.940 tons |
| OB-251 | Dec 1940 | 2 ships sunk for a total of 19.360 tons |
| OB-252 | Dec 1940 | 3 ships sunk for a total of 12.325 tons |
| OB-256 | Dec 1940 | 2 ships sunk for a total of 7.050 tons |
| OB-259 | Dec 1940 | |
| OB-261 | Jan 1941 | 1 ship sunk for a total of 6.579 tons |
| OB-269 | Jan 1941 | 1 ship sunk for a total of 5.965 tons |
| OB-279 | Feb 1941 | 2 ships sunk for a total of 9.734 tons |
| OB-280 | Feb 1941 | 1 ship sunk for a total of 1.298 tons |
| OB-284 | Feb 1941 | 1 ship sunk for a total of 5.462 tons |
| OB-287 | Feb 1941 | 1 ship sunk for a total of 6.999 tons |
| OB-288 | Feb 1941 | 9 ships sunk for a total of 38.604 tons |
| OB-289 | Feb 1941 | 3 ships sunk for a total of 16.761 tons |
| OB-290 | Feb 1941 | 3 ships sunk for a total of 12.087 tons |
| OB-293 | Mar 1941 | 3 ships sunk for a total of 32.464 tons |
| OB-302 | Mar 1941 | 2 ships sunk for a total of 5.510 tons |
| OB-304 | Apr 1941 | 1 ship sunk for a total of 8.132 tons |
| OB-306 | Apr 1941 | 1 ship sunk for a total of 6.563 tons |
| OB-309 | Apr 1941 | 2 ships sunk for a total of 12.393 tons |
| OB-310 | May 1941 | 2 ships sunk for a total of 9.982 tons |
| OB-318 | May 1941 | 10 ships sunk for a total of 55.347 tons |
| OB-317 | May 1941 | 1 ship sunk for a total of 4.553 tons |
| OB-313 | May 1941 | 2 ships sunk for a total of 12.948 tons |
| OB-312 | May 1941 | 1 ship sunk for a total of 6.434 tons |
| OB-314 | May 1941 | 1 ship sunk for a total of 5.920 tons |
| OB-322 | May 1941 | 1 ship sunk for a total of 7.402 tons |
| OB-320 | May 1941 | 2 ships sunk for a total of 10.677 tons |
| OB-319 | Jun 1941 | 1 ship sunk for a total of 4.719 tons |
| OB-327 | Jun 1941 | 4 ships sunk for a total of 27.156 tons |
| OB-329 | Jun 1941 | 4 ships sunk for a total of 23.209 tons |
| OB-328 | Jun 1941 | 3 ships sunk for a total of 14.020 tons |
| OB-324 | Jun 1941 | 2 ships sunk for a total of 9.426 tons |
| OB-323 | Jun 1941 | 1 ship sunk for a total of 7.816 tons |
| OB-330 | Jun 1941 | 2 ships sunk for a total of 10.366 tons |
| OB-336 | Jun 1941 | 3 ships sunk for a total of 11.285 tons |
| OB-337 | Jul 1941 | 2 ships sunk for a total of 8.362 tons |
| OB-341 | Jul 1941 | 2 ships sunk for a total of 10.842 tons |
69 OB convoys successfully attacked in the war.
Map showing ships hit from convoys on route OB. 155 ships with known position.