General Order 95
Strength Requirements for All Classes of Lines
A. Material(See Rule 48)
Metal crossarms shall be protected by a corrosion resistant treatment or composed of material which is corrosion resistant.
Note: Revised February 5, 2014 by Decision No. 14-02-015.
B. Minimum Size
The physical properties as a result of dimensions, shape and cross–sectional area of crossarms shall be such as to result in sufficient strength to meet the requirements of these Rules.
Part (3) added February 13,
1974 by Decision No. 82466 Revised January 21, 1992 by Resolution SU–10.
Crossarms shall be securely supported by bracing, where necessary, to withstand unbalanced vertical loads and to prevent tipping of any arm sufficiently to decrease clearances below the values specified in Section III . Such bracing shall be securely attached to poles and crossarms. Supports in lieu of crossarms shall have means of resisting rotation in a vertical plane about their attachment to poles or shall be supported by braces as required for crossarms. Metal braces or attachments shall meet the requirements of Rules 48.2 and 49.8 .
In addition to the above, a vertical load of 300 lbs. at the outer pin position shall be included in computing the vertical loads on all crossarms.
Longitudinal Loads Normally Balanced
Supply Lines: Where longitudinal loads are normally balanced, crossarms supporting
supply conductors shall have sufficient strength to withstand a load, applied
in the direction of the conductors at the outer pin position, of 700 pounds
with a safety factor of not less than unity.
Communication Lines, Class C: Where longitudinal loads are normally
balanced, crossarms supporting Class C conductors shall have sufficient strength
to withstand a load, applied in the direction of the conductors at the outer
pin position, of 400 pounds with a safety factor of not less than unity.
(2) Longitudinal Loads Normally Unbalanced: Crossarms subjected to unbalanced
longitudinal loads shall have sufficient strength to meet the strength requirements
with safety factors at least equal to those specified in
At unbalanced corners and dead ends in Grades “A”, “B” or “C” construction, where conductor tension is held by cantilever strength of pin–type insulators and pins, double crossarms shall be used to permit conductor fastenings at two insulators to prevent slipping. In lieu of double crossarms and double insulators, single crossarms may be used with single insulators and steel pins and prefabricated conductor ties.
For conductor tensions up to 2,000 pounds per conductor, double wood crossarms fitted with spacing devices at each end will be considered as meeting the strength requirements of Rules 47.2 and 47.3 .
Note: Revised March 9, 1988 by Resolution E–3076 and February 5, 2014 by Decision No. 14-02-015
D. Replacements (See Rule 44.3 )
E. Guard Arm
Guard arms shall: (i) be made of wood or other suitable material; (ii) be at least 48 inches in length; and (iii) meet the insulating efficiency of Rule 22.8. Each guard arm, including support elements, shall withstand a vertical load of 300 lbs. at either end.
Note: Added January 13, 2006 by Decision No. 05-01-030and February 5, 2014 by Decision No. 14-02-015