| Belgian State Railways Type 51 | |
| Powertype: | Steam |
| Builddate: | 1866–1905 |
| Totalproduction: | 370 |
| Uicclass: | C n2t |
| Fireboxtype: | Belpaire |
| Cylindercount: | Two, inside |
| Operator: | Belgian State Railways |
| Operatorclass: | Type 51 |
The Belgian State Railways Type 51 was a class of steam locomotives for shunting and local train service, introduced in 1866.
The locomotives were built by various manufacturers from 1866 to 1905.The machines had an outside frame with the cylinders located inside the frame.During the extended period of time in which these machines were built they underwent various changes, e.g. in the design of the water tanks, shelter, boiler and overall length.
| 4 | État Belge | |||
| 56 | 1879–1899 | État Belge (54), Pehan (2) | ||
| Tubize | 3 | 1905 | exported to China | |
| 155 | 1876–1905 | État Belge | ||
| Saint-Léonard | 3 | exported to China | ||
| 52 | 1866–1895 | État Belge | ||
| Couillet | 4 | Ouest de Mons, | ||
| 22 | 1874 | État Belge | ||
| Franco-Belge | 2 | 1874 | exported to China | |
| Franco-Belge (La Croyère) | 8 | 1906–1908 | CF Pienlo (China) | |
| Franco-Belge (Raismes) | 6 | 1906–1908 | Beijing–Hankou | |
| 57 | 1875–1900 | État Belge | ||
| 13 | 1888–1898 | État Belge | ||
| 11 | 1866 | État Belge | ||
| Carels Frères | 28 | État Belge | ||
| (Marcinelle) | 19 | État Belge | ||
| 29 | 1902–1915 | État Belge | ||
| 3 | 1885, 1895 | État Belge | ||
| 3 | 1905 | État Belge | ||
| 10 | État Belge | |||
| Lambert (Marcinelle) | 8 | 1889–1890 | État Belge |
| N O (1876) | 458 – 460 | 3 | ||
| Saint-Léonard | 2 N O (1879) | 492 – 495 | 4 | |
| Saint-Léonard | 3 N O (1879) | 501 – 505 | 5 | |
| Saint-Léonard | 4 N O (1881) | 528 – 534 | 7 | |
| Saint-Léonard | 5 N O (1881) | 567 – 572 | 6 | |
| Saint-Léonard | 6 N O (1884) | 669 – 677 | 9 | |
| Saint-Léonard | 7 N O (1884) | 685 – 689 | 5 | |
| Saint-Léonard | 8 N O (1889) | 813 – 817 | 5 | |
| Saint-Léonard | 8 N O 2 (1889) | 830 – 831 | 2 | |
| Saint-Léonard | 9 N O (1895) | 967 – 972 | 6 | |
| Saint-Léonard | 9 N O 2 (1895) | 984 – 985 | 2 | |
| Saint-Léonard | 9 N O 3 (1897) | 1073 – 1077 | 5 | |
| Saint-Léonard | 9 N O 4 (1898) | 1143 – 1146 | 4 | |
| Saint-Léonard | 9 N O 5 (1898) | 1154 – 1155 | 2 | |
| Saint-Léonard | 9 N O 6 (1900) | 1235 – 1239 | 5 | |
| Saint-Léonard | 9 N O 7 (1900) | 1245 – 1250 | 6 | |
| Saint-Léonard | 9 N O 8 (1901) | 1252 – 1261 | 10 |