🔍 Key Concepts

• Direct vs. indirect cooling systems on large slow-speed diesel engines • Which components are most sensitive to corrosion, scaling, and contamination from seawater • Typical use of central fresh water cooling systems and where sea water actually flows

💭 Think About

• Think about which engine parts require the cleanest, most controlled cooling medium and which can tolerate seawater quality • Consider which components operate at the highest temperatures and tightest tolerances, and whether seawater contact would be acceptable there • Ask yourself: in a typical engine room cooling diagram, where does sea water first enter and what does it cool directly before any heat exchangers?

✅ Before You Answer

• Identify which components are usually cooled by fresh water jackets rather than seawater • Eliminate any choice where direct seawater contact would likely cause rapid corrosion or fouling • Recall that in many systems, seawater’s main role is in heat exchangers/condensers, not in direct contact with precision engine parts