Question 611 Deck General

A) The stress on the heel block is less at 60°. This is the correct answer. As the boom angle increases from 20° to 60°, the tension on the heel block decreases because the vertical component of the load force is reduced. At a 60° angle, the vertical force on the heel block is lower compared to the 20° angle, resulting in less stress. The other options are incorrect: B) The change in angle of elevation does affect the stresses in the head block, as the tension on the head block will decrease as the boom angle increases. C) The stress on the topping lift is actually lower at 60° since the vertical force component is reduced. D) The thrust on the boom is greater at 20° because the horizontal force component is higher at shallower boom angles.