TB/T 3074 is the Chinese railway industry standard that specifies the protection of railway signalling equipment against the lightning electromagnetic impulse. Railway signalling is one of the more demanding applications of lightning protection, for reasons that follow from the way the railway is built: the track and the signalling cables run outdoors for hundreds of kilometres, the rails and the catenary form an efficient collector for lightning current, and the equipment that must be protected is distributed along the line in equipment rooms and track-side cabinets rather than concentrated in a single protected building. The standard therefore defines the protection zones along the railway, the bonding and earthing arrangements appropriate to each, the selection and installation of surge protective devices on the signalling circuits and on the power supplies feeding them, and the shielding and routing rules for cables. It is applied together with the industry standard for the lightning test methods used to verify signalling equipment.