Nummer: 18813
| Area : | Western Area |
| Sea area : | Gibraltar Area |
| Date of attack : | 10.01.1945 |
| Nationality of U-boat : | German |
| U-boat : | U 870 |
| Commander : | Hechler |
| Grid : | CG 9585 |
| presumed target type : | Steam Freighter |
| presumed tonnage : | 6000 BRT |
| presumed result : | damaged |
| Used weapon(s) : | Torpedo(es) |
| Convoy : | KMS.76 |
| Date of observation : | 10.01.1945 |
| Time of observation : | 16:03 |
| Nationality of target : | British |
| Actual type of target : | Steam Freighter |
| Name of target : | Blackheath |
| Year of launch : | 1936 |
| Actual tonnage : | 4637 BRT |
| Actual result : | sunk |
| Position of target : | 35.49n 06.03w |
| Convoy : | KMS.76 |
| Route of convoy : | United Kingdom - Gibraltar - Port Said (slow) |
| Remark to convoy : | Since Oct 1942; since May 1943 combined mit OS in Atlantic (counter traffic = MKS) |