General Order 64

Detail Construction Requirements For Trolley Contact Lines And Feeders – Class “T” Circuits

83    Grades Of Construction And Strength Requiremetns.

(See Section III and Section V.)  Class “T” lines, in determining strength requirements, are classed as ordinary supply lines of equal voltage and will take grades of construction accordingly.  This will generally mean Grade “C” construction for D.C. trolley lines of 0-750 volts, Grade “A” or “B” being required at crossings over railways according to the importance of the railway crossed.

In computing the strength of poles, wires, etc., the effect of the pull span wires, stresses due to brackets and other similar loading must be considered as part of the dead weight loading in addition to the wind stresses, etc., mentioned in Section V.