🔍 Key Concepts

• SOLAS and 46 CFR requirements for lifeboat launching appliances • Relationship between wire rope diameter and drum diameter to prevent excessive bending stress • Why safety gear often uses a minimum bending radius that is a specific multiple of the rope diameter

💭 Think About

• Think about what happens to a wire rope when it is bent around too small a drum—how does that affect fatigue and safety? • Compare the choices: which multiples would likely be too small for safe, repeated operation of a lifeboat winch? • Recall similar rules you may have seen for sheaves and drums on other marine lifting gear—are they usually closer to the smaller or larger multiples?

✅ Before You Answer

• Verify in 46 CFR the specific minimum drum diameter multiple required for lifeboat falls (not general cargo gear) • Check whether the rule distinguishes between drums and sheaves or applies the same multiple to both • Confirm that the multiple is intended to reduce bending stress and wire fatigue during frequent lowering/hoisting of lifeboats