USCG Exam PracticeCargo gear and rigging
Which safety device on a modern cargo crane or winch is specifically designed to prevent the hook block from being drawn up into the head block?
- A. The overload cut-out, which stops hoisting when the SWL is exceeded
- B. The slack-rope warning, which alerts the operator when the runner goes slack
- ✓ The upper limit switch, which stops the hook before two-blocking occursCorrect
- D. The luffing limit switch, which stops the jib at the end of its travel
Why C is correct
NAVEDTRA 14343 §9-4 identifies limit switches that stop the hook before two-blocking as a required safety device on modern cargo machinery. The luffing limit switch stops luffing at the ends of travel, and the overload cut-out prevents lifting beyond the SWL — these are separate functions.
Cited:NAVEDTRA 14343 §9-4