The Hellenic Railways Organization or OSE (Greek: Οργανισμός Σιδηροδρόμων Ελλάδος or Ο.Σ.Ε.) is the Greek national railway company which owns, maintains and operates all railway infrastructure in Greece with the exception of Athens' rapid transit lines. Train services on these lines are run by TrainOSE S.A., a former OSE subsidiary. In addition OSE owns and maintains the rolling stock used by TrainOSE and maintains preserved special rolling stock, withdrawn locomotives and railcars.