| Class 55 | |
| Powertype: | Diesel |
| Builder: | BN/ACEC/SEMG |
| Builddate: | 1961-1962 |
| Totalproduction: | 42 |
| Uicclass: | Co′Co′ |
| Driverdiameter: | 1010mm |
| Length: | 19.55m (64.14feet) |
| Fueltype: | Diesel |
| Primemover: | GM 16-567C |
| Enginetype: | Two-stroke 45° V-engine diesel |
| Cylindercount: | 16 |
| Cylindersize: | Bore x Stroke x |
| Transmission: | Electric (ACEC) |
| Maxspeed: | 120km/h |
| Operator: | SNCB/NMBS |
| Operatorclass: | 55 |
| Numinclass: | 23 |
| Fleetnumbers: | Various remain in range 5501-5542 |
| Disposition: | In service |
The SNCB Class 55 is a NMBS/SNCB diesel locomotive.
Six of these locomotives (5501, 5506, 5509, 5511, 5512 and 5514) are outfitted with TVM 430 signaling and a Scharfenberg coupler. This is for hauling broken-down or unpowered TGVs on line 1. They display a horizontal red band and the letters "TVM". Some locomotives are owned and used by the Société Nationale des Chemins de Fer Luxembourgeois as CFL Class 1800.[1]