t-4 POLES: 15-17. All poles must be roofed. 15-18. Set poles "back to back" or "gain to gain" on 15-19. Poles shall be set to the following depths unless straight lines. On curves, gains face apex of the angle. otherwise approved by the Engineer. Length of pole in feet Setting depth in soil Setting depth in rock 20 5 3 25 5 3.5 30 5.5 3.5 35 6 4 4o 6 4 45 6.5 45 50 7 4.5 15-20, Cut gains for arms as required with the axis of 15-21. Where more than one gain is required, the gains the pole to a depth of not more than 1/2 inch with a flat surface 4-3/4 inches high and approximately 4 inches wide. shall be parallel and all holes shall be squared with the axis of the pole. 15-22, When the pole has sweep or curvatures, the gains 15-23. Keep a11 poles free from posters, banners, nails, shall be made on the concave side. radio antennas, signs, or other devices that might interfere with safe climbing of the pole. 15-24, All operating poles, such as transformer poles and cable poles shall be stepped from a point ten (10) feet above the ground to within 18 inches to 36 inches below the lowest arm, unless otherwise directed. Steps shall be in line and shall be spaced approximately 18 inche between consecutive steps. 15-4