🔍 Key Concepts

• Crankcase explosions in diesel engines and typical causes (oil mist, hot spots) • Purpose of crankcase relief (explosion) doors/valves and why they must NOT be forced • Standard safety practice immediately after a crankcase explosion when the casing is still intact

💭 Think About

• After an explosion, what is the greatest remaining danger inside the crankcase: pressure, temperature, or fresh ignition sources? How does that affect whether you open or leave things closed? • Think about what happens if you open any access (doors, relief valves, crankcase covers) while internal surfaces are still very hot and oil mist may still be present. • Which action is focused on preventing a second, more serious explosion rather than just checking engine condition or operating other systems?

✅ Before You Answer

• Verify which option involves physically opening a path into the crankcase or related spaces and whether that is safe while hot. • Confirm standard guidance: does marine practice advise to keep the crankcase closed and allow it to cool before inspection, or to open it right away? • Check which choices are routine operating actions (indicator cocks, lube oil pump, relief valves) versus a clear safety precaution after an internal explosion.