General Order 95
Detailed Construction Requirements for Trolley and Electric Railway
Contact and Feeder Conductors and Their Supporting Messengers,
Span Wires, Etc. (Class T Circuits)
74.3 Material and Strength
In determining strength requirements, Class T lines are classed as supply lines of equal voltage and will take grades of construction accordingly. This will generally mean Grade “C” construction for DC trolley lines of 0 - 750 volts, Grade “A” or “B” being required at crossings over railways according to the importance of the railway crossed (see Rule 22.9 , Table 3 , Rule 49.4 and Section XI ).
The minimum size which shall be used for trolley contact conductors on public streets or highways is No. 0 solid medium–hard–drawn copper, or other wire of equal strength.
The minimum size of wire to be used as a feeder span or feeder auxiliary span wire shall be No. 4/0 stranded medium–hard–drawn copper or other wire of equal strength.