General Order 64-A
Detailed Construction Requirements For Communication Lines
(Class C Circuits)
84.7 Climbing and Working Space.
A. Climbing Space.
General: A climbing space shall be provided on one side
or quadrant of all poles or structures except where specifically exempted in
these rules and shall be measured from the center line of pole. A metal back brace shall be assumed as one
of the arms of double arm construction and where used the requirements for
double arm construction shall be met.
The climbing space on poles shall be maintained in the same quadrant of the pole for a minimum distance of 4 feet vertically above and below each conductor level through which it passes, and its location shall not be changed to any but an adjacent quadrant between any two consecutive conductor levels.
(2) Dimensions Where Buck Arms Are Not Used: The climbing space on the structures carrying line arms only shall have the following dimensions:
For toll and trunk circuits the climbing space shall be not less than 18 inches by 30 inches.
For exchange circuits the climbing space shall not be less than 30 inches square.
For all circuits on joint poles the climbing space shall be not less than 30 inches square.
(3) Dimensions Where Buck Arms Are Used: The dimensions for climbing space shall be fixed according to the following cross arm combinations. These dimensions are based on the minimum 3 inch pin spacing of this Order.
Where the Combination in Double Line
Arm and Double Buck Arm Construction Leave:
3 pin positions from the pole vacant in each double arm.
Where the Combination is
Double Buck Arm and Single Line Arm Construction or Vice Versa, and the
Climbing Space is left open opposite side of the pole from the single are
3 pin positions from the pole vacant in single arm.
Where the Combination is
Single Line and Single Buck Arm leave:
3 pin positions from pole vacant in one single arm.
d) Alternative: Where it is impracticable to locate the
climbing space in one of the quadrants specified above, it may be located in
another quadrant, provided any cross arm which falls within it is treated as
one of the arms of a double arm installation.
In applying the pin position spacing as prescribed above, it is contemplated that the minimum spacing in Table 2, Case 15 will be used. In the event the cross arms are not bored to these specifications, a spacing of conductors to give equivalent dimensions will be considered as meeting the requirements.
The above climbing space requirements do not apply to a cross arm and its related buck arm occupying the top position on the pole, provided no other cross arm on the pole is within 4 feet of the buck arm.
(4) Vertical Runs: Vertical runs of wire attached directly to the pole and their suitable protective covering, and guys and Unenergized portions of conductor deadending equipment shall not be held to obstruct climbing space provided one only of such obstruction is installed between any two conductor levels. This shall not be held to permit unnecessary impairment of climbing space.
(5) Conductors Attached Directly to Pole: The climbing space requirements do not apply to the 3 feet of pole next below the topmost conductor for open wire conductors attached directly to poles which carry no cross arms.
(6) Bracketed Service Wires: Brackets used for the distribution of paired wire service drops other than those originating from conductors supported on crossarms may be attached to both the face and the back of the poles, provided that if other facilities are supported at higher levels on the pole an unobstructed climbing space 30 inches square shall be provided using any one of the service drops as one side of such space and having one other side perpendicular to it and tangent to the surface of the pole. (See App. G, Fig. 88.)
A suitable working space shall be provided on all poles, the depth of same to be measured horizontally from the face of the crossarm. (See App. G, Fig. 37.)