🔍 Key Concepts

• How a mechanical overspeed trip on a diesel works (centrifugal weights move outward when RPM is too high) • Which part in the illustration is driven by the engine and will react first to overspeed (look closely at piece #10 and its connection to the rotating shaft) • How motion from the rotating trip mechanism is transmitted to the fuel rack / shutoff rod (follow how #10 interacts with #9, #11, and then #8)

💭 Think About

• When the engine exceeds safe RPM, which part in this drawing would feel the change in speed directly? Trace from the rotating shaft to the numbered pieces. • If the centrifugal weights try to move outward, will that make piece #10 push, pull, or rotate something? How would that motion then move the latch connected to the vertical shutoff rod (#8)? • Think about the direction the spring is pulling on the vertical rod and what must happen to overcome that spring and trip the shutdown.

✅ Before You Answer

• Identify which numbered part is the rotating flyweight carrier and which is the vertical trip/shutoff rod. • Confirm which way the spring on the vertical rod (#8) is trying to move it under normal conditions (up or down). • Verify which linkage piece (#9 or #11) actually contacts the rod connected to #8 when #10 reacts to overspeed. That tells you which part must move, and in what direction, at the instant of overspeed.