CPV code 50221000 designates Repair and maintenance services of locomotives in the Common Procurement Vocabulary (CPV 2008), the EU classification used to describe the subject of public contracts.
50221000 sits under 50220000 (Repair, maintenance and associated services related to railways and other equipment) and groups 4 more specific sub-codes. When classifying a tender, choose the narrowest code that still covers the full subject of the contract.