Detailed Construction Requirements for Trolley
and Electric Railway
Contact and Feeder Conductors and Their Supporting Messengers,
Span Wires, Etc. (Class T Circuits)
The provisions of Rule 52.4 apply to crossarm supporting Class T conductors except that any crossarm (either of wood or metal) or any appliance used in lieu thereof attached to poles or structures which support only Class T conductors of more than 750 volts, or such conductors and private communication conductors of the same ownership, need not be marked as supporting high voltage conductors.