What is the lead line tension needed to lift a 3,200-pound bundled conductor using a four-part block and tackle with a 10% friction loss?

• A. 800 pounds
• B. 1,120 pounds
• C. 1,600 pounds
• D. 3,200 pounds

Answer: (B)

To calculate the lead line tension needed to lift the bundled conductor, you first need to consider the total weight being lifted and the mechanical advantage provided by the four-part block and tackle system. A four-part system divides the weight by four, which means the initial load of 3,200 pounds is effectively reduced to 800 pounds in an ideal scenario without any friction loss.

However, because there is a 10% friction loss to account for, the effective weight lifted is increased due to the additional force needed to overcome this friction. To calculate the lead line tension considering the friction, you first determine the weight per part of the tackle system:

1. Calculate the ideal tension:

( \frac{3,200 \text{ pounds}}{4} = 800 \text{ pounds} )

2. Account for friction loss:

Since you have a 10% friction loss, you need to increase the calculated tension by 10%:

( 800 \text{ pounds} \times (1 + 0.10) = 800 \times 1.10 = 880 \text{ pounds} )

However, it seems that we need to reconsider how we interpret the total force when friction