General Order 64
Section VIII
Detail Construction Requirements For Trolley Contact Lines And Feeders – Class “T” Circuits
87 Span Wires.
(a) Span wires, not including bracket span wires, supporting, or attached to wires which support trolley contact conductors or appurtenances in electrical contact thereto shall be insulated as follows (this includes cross span wires, pull-offs, trolley strain guys, etc.):
1. There shall be suitable and effective insulator (preferably of the interlocking strain type) inserted in the span wire not less than 4 feet nor more than 5 feet (measured along the span wire) from each suspension or point of support of the trolley contact conductor or its appurtenances which have electrical contact thereto. (See Appendix E, Fig. 28.)
2. When a span wire is so attached to the trolley contact conductor or appurtenance which it supports that it makes an acute angle with the trolley contact conductor, and the insulator placed in the span wire in accordance with the last above paragraph, is less than a four foot perpendicular distance from the trolley contact conductor, then in addition to compliance with the last above paragraph, an additional insulator shall be placed in the span wire which shall be not less than a four foot or more than a ten foot perpendicular distance from the trolley contact conductor. (See Appendix E, Fig 29.)
3. Where the span wire is supported from a steel pole or other metal structure an additional suitable and effective insulator (preferably of the interlocking strain type) shall be inserted adjacent to such support, the distance measured along span wire to the insulator to be not less than 6 feet nor more than 9 feet from the pole or support. (See Appendix E, Fig. 30.)
4. No insulator shall be required in any span wire supporting two trolley contact conductors between the suspensions of such conductors, provided these suspensions are not more than 18 feet apart. (See Appendix E, Fig. 31.)
5. Rules (a) 1 (Fig. 28) and (a) 2 (Fig. 29) shall not apply to feeder wires used as span wires, but in this case Rule (a) 3 (Fig, 30) and (a) 4 (Fig. 31) shall apply whether supporting structures be of wood or metal. Such feeder span wires, however, shall be well insulated except at points of contact with trolley contact conductor, and shall be continuous without splice from the main feeder to a point not less than one foot or more than five feet beyond the last trolley contact conductor to which they are attached, where the feeder wire shall terminate in a suitable strain insulator (preferably interlocking). Feeder span wires shall be of a strength not less than that of 4/0 stranded copper cable. (See Appendix E, Fig. 32.)
Note - In territories where fog conditions prevail, it is recommended that two strain insulators, instead of one, be used at the location specified in Rule 87 (a)(3).
(b) Where span wires in bracket construction are used, and such span wires support, or are attached to span wires support, trolley contact conductors or appurtenances in electrical contact thereto, such span wires shall be insulated as follows:
1. There shall be suitable and effective insulator inserted in the span wire between the suspension of the trolley conductor and each point of support of the span wire, such insulators to be not less than two feet from the trolley contact conductor. (See Appendix E, Fig. 33.)
2. The suspension or hanger supporting the trolley contact conductor shall be adequately insulated for the trolley voltage. (See Appendix E, Fig. 33.)
3. Where brackets are supported on wooden poles which support no other conductors than those of the railroad company, Rule (b) 1 (Fig. 33) need not apply. (See Appendix E, Fig. 35.)
4. Where brackets are made of wood or are suitably insulated along their length perpendicular to the pole, that part of Rule (b)1 (Fig. 33) which prescribes an insulator between the suspension and the point of bracket support need not apply.
5. Where “feeder” wires are used partially as bracket span wires, the span wire insulator nearest the pole may be inserted at a distance greater than two feet from the trolley contact conductor, but in no case shall it be closer than four feet to the pole. Such feeder span wires shall be well insulated except at points of contact with trolley contact conductor, and shall be continuous without splice from the main feeder to the span wire insulator farthest from the pole, and shall be of strength not less than that of 4/0 stranded copper cable. (See Appendix E, Fig. 36.)