🔍 Key Concepts
• Relationship between brake horsepower (BHP) and bollard pull for conventional tugs
• Typical order of magnitude of static bollard pull (in tons) for a harbor tug of known horsepower
• Dimensional reasoning: how a factor changes the result when you divide BHP by 100 then multiply
💭 Think About
• If a tug has about 3,000–4,000 BHP, what range of bollard pull (in tons) is realistic for a conventional single‑screw harbor tug? Use that to estimate the factor.
• Take a sample BHP (for example, 2,000 BHP). Divide by 100 and then multiply by each choice. Which results look physically reasonable for bollard pull in tons for a small tug?
• Compare how big the factor would need to be to avoid giving an unrealistically high or low bollard pull for common tug sizes.
✅ Before You Answer
• Estimate a realistic bollard pull for a typical 2,000–3,000 BHP tug from your general knowledge or study materials.
• Check that the units make sense: BHP is power, bollard pull is force expressed as tons; the factor is empirical but should not give extreme values.
• Before choosing, confirm that the factor you pick gives plausible bollard pull values across a range of normal tug horsepowers (e.g., 1,500–4,000 BHP).