General Order 64-A
Section V
Detailed Construction Requirements For Supply Lines
(Class H, L and T Circuits)
54.7 Climbing and Working Space
A. Climbing Space. (See App. G, Figs 35-39)
(1)
General: Climbing space shall be provided on one side
or quadrant of all poles or structures and shall be measured from the
centerline of pole.
The climbing space shall be
maintained in the same quadrant of the pole for a minimum distance of 4 feet
vertically both 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.
The climbing space in all
combination line and service buck arm construction must be maintained in
accordance with the rules covering climbing space for buck arm construction for
voltages of 750-7500. (See Rule
54.8-B.)
(2)
Dimensions Where Buck Arms are Not
Used: The climbing space
on poles or structures carrying line arms only shall have the following
dimensions:
For conductors of 0-7500 volts
the climbing space shall not be less than 30 inches square.
For conductors of 7500-68,000
volts the climbing space shall not be less than 36 inches square and more than
68,000 volts not less than 48 inches plus ½ inch per K.V. in excess of 68 K.V.
and these dimensions shall be increased as much as practicable if such
conductors are to be energized when it is required that men work above them.
(3) Dimensions where Buck Arms Are Used: The dimensions for climbing space shall be fixed according to voltage classifications given below. These dimensions are based on the minimum pin spacing given in this order for the voltages involved.
a)
Where the combination is
double line and double buck arm construction, leave:
No. 1 pin position from pole
vacant in each double arm for 0-750 volts.
No. 1 pin position from pole
vacant in one double arm and No. 1 and No. 2 pin positions vacant in the other
double arm voltages in excess of 750.
b)
Where the combination is
double line arm and single buck arm construction or vice versa, the climbing
space being left open on the opposite side of the pole from the single arm,
leave:
No. 1 pin position from pole
vacant in the single arm for 0-750 volts.
No. 1 pin position from pole
vacant in line and buck arms for voltages in excess of 750, or leave
No. 1 and
No. 2 pin positions vacant in the single arm for voltages in excess of 750.
c)
Where the combination is
single line arm and single buck arm construction, the climbing space being left
open on the opposite side of the pole from the arms, leave:
No. 1 pin position from pole
vacant in one arm for 0-750 volts.
No. 1 pin position from pole
vacant in the line and buck arm for voltages in excess of 750.
d)
Alternatives: 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 pine position spacings
as prescribed above it is contemplated that the minimum spacings of Table 2,
Case 15, will be used. In the event the
crossarms are not bored to these specifications a spacing of conductors to give
equivalent dimensions will be considered as meeting the requirements.
In locations where climbing
spaces as defined above do not lend themselves to the construction used an
unobstructed climbing space, measured from the nearest face of the crossarms,
30 inches square through conductors of less than 7500 volts and 36 inches
square through conductors of more than 7500 volts, shall be considered as
meeting the requirements of this order.
(4) Vertical Runs: Vertical runs of wire attached directly to the pole and their suitable protective coverings, guys and Unenergized portions of conductor dead-ending equipment shall not be held to obstruct climbing space provided one only of such obstructions is installed between any two conductor levels. This shall not be held to permit unnecessary impairment of climbing space.
(5) Conductor Dead Ends: Where conductors are dead-ended directly to the pole such conductors and their connecting taps shall be so arranged that no energized portion of them enters the climbing or working space.
B Working Space.
(1) General: A suitable working space through which no lateral, vertical or diagonal conductor passes shall be provided between conductor levels on all poles in such position This requirement does not apply between line arm conductors and the conductors on related buck arms.
(2)
Dimensions of Working Space: The following rules apply:
The width of the working space
shall be the distance between the outside pin position of the cross arm
involved.
The height of the working space
shall be the distance between the conductor levels as fixed by Table 2 for the
voltages involved.
The depth of the working space
measured horizontally from the face of the crossarm shall be equal to the width
of the climbing space required for the highest voltage conductor at the level
concerned.
Line arms and related buck arms
may for the purpose of designating working space only, be considered as
supporting their respective conductors at the same level.