Nummer: 17106
| Area : | Western Area |
| Sea area : | North Atlantic |
| Date of attack : | 20.09.1943 |
| Time of attack : | 04:57 |
| Nationality of U-boat : | German |
| U-boat : | U 270 |
| Commander : | Otto |
| Grid : | AK 0366 |
| presumed target type : | Destroyer |
| presumed result : | sunk |
| Used weapon(s) : | Acoustic homing torpedo (gnat) |
| Convoy : | ON.202 |
| Date of observation : | 20.09.1943 |
| Time of observation : | 02:56 |
| Nationality of target : | British |
| Actual type of target : | Fregate |
| Name of target : | Lagan (K.259) |
| Year of launch : | 1942 |
| Actual tonnage : | 1370 ts |
| Actual result : | not repaired, total loss |
| Position of target : | 57.09n 27.28w |
| Footnote : | The attacks of U-boats of "Leuthen" group against the combined convoys ON.202 and ONS.18 had been the first attacks with the acoustic torpedo T-5 called "Zaunkönig" (gnat). -"Lagan" was towed into port, but became a total loss. |
| Convoy : | ON.202 |
| Route of convoy : | United Kingdom - North America |
| Remark to convoy : | 1st series: Jul 1941 to Mar 1943 ON and ONS combined, later ON mit continuing and ONS with new numbering (counter traffic HX and SC) |