What is the safe working load rule of thumb for wire rope?

What is the safe working load rule of thumb for wire rope?

• A. D² × 8 × 2000
• B. D² × 10 × 2000
• C. D³ × 8 × 1000
• D. D² × 6 × 2000

Answer: (A)

The main idea here is that the safe working load of wire rope scales with the rope’s cross-sectional area, which means it grows with the square of the diameter. In this rule-of-thumb formula, you estimate SWL by multiplying the diameter squared by a constant: SWL ≈ d^2 × 8 × 2000. The d^2 captures how a bigger rope can carry more load because its cross-sectional area increases with the square of the diameter, while the constants 8 and 2000 convert that area into a practical load in pounds for this training set. So, for example, a rope with a 1-inch diameter would have an estimated SWL of 1^2 × 8 × 2000 = 16,000 pounds. If the diameter doubled, the SWL would go up by a factor of four, not eight or six, reflecting the squared relationship. The other options don’t fit this typical rule because they either use the wrong exponent on diameter (D cubed instead of squared) or use a different multiplier (6 or 10) or a different base (1000 instead of 2000). This choice aligns with the standard form taught in this material.

The main idea here is that the safe working load of wire rope scales with the rope’s cross-sectional area, which means it grows with the square of the diameter. In this rule-of-thumb formula, you estimate SWL by multiplying the diameter squared by a constant: SWL ≈ d^2 × 8 × 2000. The d^2 captures how a bigger rope can carry more load because its cross-sectional area increases with the square of the diameter, while the constants 8 and 2000 convert that area into a practical load in pounds for this training set.

So, for example, a rope with a 1-inch diameter would have an estimated SWL of 1^2 × 8 × 2000 = 16,000 pounds. If the diameter doubled, the SWL would go up by a factor of four, not eight or six, reflecting the squared relationship.

The other options don’t fit this typical rule because they either use the wrong exponent on diameter (D cubed instead of squared) or use a different multiplier (6 or 10) or a different base (1000 instead of 2000). This choice aligns with the standard form taught in this material.