CPC Subgroup
E01B 3/34 with pre-tensioned armouring or reinforcement (pre-tensioned armouring or reinforcing elements E04C5/00)
Full Title
Transverse or longitudinal sleepers (for switches or crossings E01B7/22); Other means resting directly on the ballastway for supporting rails > made from concrete or from natural or artificial stone (manufacture B28) > with armouring or reinforcement (hollow sleepers E01B3/30) > with pre-tensioned armouring or reinforcement (pre-tensioned armouring or reinforcing elements E04C5/00)