Nummer: 19904
| Area : | Arctic Ocean |
| Sea area : | Barents Sea |
| Date of attack : | 06.07.1942 |
| Time of attack : | 16:38 |
| Nationality of U-boat : | German |
| U-boat : | U 255 |
| Commander : | Reche |
| Grid : | AT 7216 |
| presumed target type : | Steam Freighter id |
| presumed tonnage : | 10900 BRT |
| presumed result : | sunk |
| Used weapon(s) : | Torpedo(es) |
| Convoy : | PQ.17 d |
| Date of observation : | 06.07.1942 |
| Nationality of target : | American |
| Actual type of target : | Steam Freighter |
| Name of target : | John Witherspoon |
| Year of launch : | 1942 |
| Actual tonnage : | 7191 BRT |
| Actual result : | sunk |
| Position of target : | 70.30n 52.30e |
| Convoy : | PQ.17 d |
| Route of convoy : | Iceland - Russia |
| Remark to convoy : | Sep 1941 to Dec 1942, then JW (counter traffic = QP) |