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If an eagle or other bird were to land on the obstructed side of the cross- <br /> arm, contact between the phase and ground would be prevented by the separa- <br /> tion of the two wires by about 5 feet vertically. In addition, contact is <br /> further prevented by the fact that the ground wire runs on the opposite side <br /> of the pole from the phase wire on top of the crossarm. Contact between two <br /> phases is also extremely unlikely due to the approximate 3 feet vertical <br /> separation of the wires. <br /> 2) The Stacked Structure is represented in Figure 3.8-6 and shows the three <br /> phases mounted one above the other in a stacked fashion with a ground wire <br /> mounted at the top of the pole. The separation of phases and ground is a <br /> minimum of eight feet so there is no chance for power contact to be made. <br /> There is a lightning rod at the top of the pole with an insulated wire run- <br /> ning down the pole to the ground. <br /> 3) The Switch Structure is represented in Figure 3.8-8 and is a modified Tangent <br /> Structure, to accommodate a switch. The Tangent Structure is discussed in <br /> paragraph 4. This structure may be erected with the contacts on the upper <br /> crossarm rotated in toward the pole or away from the pole. The groundwire on <br /> this structure is mounted 6 inches below the top of the pole and again, there <br /> is a lightning rod with an insulated wire running from the rod to the <br /> ground. The top crossarm is mounted 7 '-4" below the top of the pole, and it <br /> is assumed that an eagle or other large bird would land on the top of the <br /> pole or on the unobstructed end of the upper crossarm. If an eagle were to <br /> land on the end of the crossarm having the phase mounted on it, there would <br /> be no chance of contact with an average wingspan less than 90 inches. Ninety <br /> inches is the diagonal distance between the closed switch mounted in the out- <br /> ward tilted position and the ground wire at the top of the pole. With the <br /> switch mounted in the position rotated toward the pole, the diagonal distance <br /> is reduced to 66.2", but there would only be 28 inches between the phase and <br /> the pole horizontally. It would be highly unlikely that a large bird would <br /> choose to land in this area. In addition, there is a 60-inch vertical <br /> separation between the phase wire and the ground wire leaving the most remote <br /> possibility contact would be made. <br /> 4-163 <br /> REYISED FEB 13 `�7 <br />