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.