Cyclopedia of heating, plumbing and sanitation; a complete reference work . Pig. 68. Additional Stiffness Secured by Use of Crib-Bracing. Cross-Arms. Cross-arms, where possible, should be of longleaf yellow pine, or of Oregon or Washington fir, of sound wood, 365 70 ELECTRIC WIRING thoroughly seasoned and free from sap, cracks, or large knots. Theyshould be imi less than 3^ Inches thick by -l, inches deep, the lengthdepending upon the number of pins required. Cross-arms, after being properly seasoned, should be paintedwith two coats of lead paint before erection. They should then besnugly fitt
Cyclopedia of heating, plumbing and sanitation; a complete reference work . Pig. 68. Additional Stiffness Secured by Use of Crib-Bracing. Cross-Arms. Cross-arms, where possible, should be of longleaf yellow pine, or of Oregon or Washington fir, of sound wood, 365 70 ELECTRIC WIRING thoroughly seasoned and free from sap, cracks, or large knots. Theyshould be imi less than 3^ Inches thick by -l, inches deep, the lengthdepending upon the number of pins required. Cross-arms, after being properly seasoned, should be paintedwith two coats of lead paint before erection. They should then besnugly fitted into the gain of the pole, and securely fastened witha boll not less than | inch indiameter driven through ;ihole of slightly less diameterpreviously bored in the galvanized-iron washernot less than 2 inches indiameter should be placedunder the head and nut of. Fig. 69. Two-Poles Used in Making Turnon Heavy Line. bolt. The cross-arms should be at rightangles to the pole, andshould be parallel to oneanother where two ormore arms are used onthe same pole. The cross-armsshould be braced withgalvanized-iron braces approximately 1 ) inches wide, { inch thick,and from 18 to 30 inches in length. The braces should be fastenedto the cross-arm by means of f-inch galvanized-iron bolts passingthrough the brace and the cross-arm, washers being used under thenut and head of each bolt. Guys should be provided for the cross-arms in case of unusual strain. The dimensions of cross-arms re-quired for various numbers of pins, are given verv completely in a 366 ELECTRIC WIRING 77 paper read by Mr. Paul Spencer before the Atlantic City Convention of the National Electric Eight Association in 1906, and reprintedin a number of the technical journals. Wherever practicable, cross-arms should be placed on the polesbefore the poles are erected, as not only can they be
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