Tables 1-2 and 1-3 list the approximate safe work- ing loads of new fiber lines with a safety factor of 5. NOTE: These are for reference only. Check the manufacturer’s ratings before determining the safe working loads, as they may differ from the tables. You may not always have a chart available to tell you the safe working load for a particular size of line. There is a rule of thumb that will adequately serve your needs on such an occasion. The formulas below are examples of synthetic fiber lines used for rigging, not slings. For  nylon  or  polyester  line,  change  the  line diameter into eighths of an inch, square the numerator, and  multiply  by  60. Example:   1/2-inch nylon line = 4/8-inch diameter SWL = 4 x 4 x 60 = 960 lb For polypropylene line, multiply the diameter by 40, and for polyethylene, by 35. Remember that the strength of a line decreases with age, use, and exposure to excessive heat, boiling water, or sharp bends. Especially with used line, you should give  these  and  other  factors  affecting  strength  careful consideration  and  make  proper  adjustment  in  the breaking strength and SWL of the line. WIRE ROPE During the course of a career, CEs often need to hoist or move heavy objects. Wire rope is used for heavy-duty work. In the following paragraphs, we will discuss the characteristics, construction, and usage of many types of wire rope as well as the safe working load, use of attachments and fittings, and procedures for the care and handling of wire rope. Table 1-2.—Safe Working Load of Fiber Line APPROXIMATE SAFE WORKING LOADS OF NEW FIBER LINES — POUNDS Three-Strand Line Safety Factor = 5 Nominal Line Manila Nylon Polypropylene Polyester Polyethylene Diameter (inches) 3/16 100 200 150 200 150 1/4 120 300 250 300 250 5/16 200 500 400 500 350 3/8 270 700 500 700 500 1/2 530 1,250 830 1,200 800 5/8 880 2,000 1,300 1,900 1,050 3/4 1,080 2,800 1,700 2,400 1,500 7/8 1,540 3,800 2,200 3,400 2,100 1 1,800 4,800 2,900 4,200 2,500 1 1/8 2,400 6,300 3,750 5,600 3,300 1 1/4 2,700 7,200 4,200 6,300 3,700 1 1/2 3,700 10,200 6,000 8,900 5,300 1 5/8 4,500 12,400 7,300 10,800 6,500 1 3/4 5,300 15,000 8,700 12,900 7,900 2 6,200 17,900 10,400 15,200 9,500 1-4