USCG Exam PracticeCargo gear and rigging
In a single swinging boom rig, friction in the tackle system reduces the theoretical mechanical advantage. According to NAVEDTRA 14343 §8-2, approximately how much loss per sheave should be allowed when estimating actual mechanical advantage?
- A. Five percent per sheave
- ✓ Ten percent per sheaveCorrect
- C. Fifteen percent per sheave
- D. Twenty percent per sheave
Why B is correct
NAVEDTRA 14343 §8-2 states that friction reduces the ideal mechanical advantage and that one should allow roughly ten percent loss per sheave when estimating practical mechanical advantage. This loss accumulates with each additional sheave in the system.
Cited:NAVEDTRA 14343 §8-2