The Combined Nomenclature (CN), v1:2025
8604 00 00: Railway or tramway maintenance or service vehicles, whether or not self-propelled, e.g., workshops, cranes, ballast tampers, trackliners, testing
https://www.dst.dk/en/Statistik/dokumentation/nomenklaturer/kn?id=3297a864-18b0-4927-8f75-9f2fa29c9c69