Question 44 3AE01 - Third Assistant Engineer

The illustrated device is used to __________. Illustration MO-0050

Diagram for USCG 3AE01 - Third Assistant Engineer: The illustrated device is used to __________. Illustration MO-0050
A supply cylinder lubricating oil to the engine
B meter fuel oil to the injectors
C admit the correct amount of starting air to the cylinders in proper order
D actuate exhaust valves in the correct sequence
AI Explanation

The Correct Answer is A ### Explanation for Option A (Correct Answer) Illustration MO-0050 typically depicts a **multi-point lubricator** or **timing lubricator**. This specialized device is used on large two-stroke slow-speed diesel engines (like those used in marine propulsion) to precisely deliver small, measured amounts of lubricating oil directly to the cylinder liner walls (the cylinder lubricating points). The device is often driven by the engine camshaft or crankshaft to ensure the oil is injected at the optimal moment in the piston stroke (usually when the piston skirt is below the injection points, minimizing oil leakage and maximizing distribution). Therefore, its primary function is to **supply cylinder lubricating oil to the engine**. ### Explanation for Incorrect Options **B) meter fuel oil to the injectors:** This is the function of the **fuel pump** (specifically, the high-pressure fuel pump) which pressurizes and meters fuel to the fuel injectors, not the lubricator shown. **C) admit the correct amount of starting air to the cylinders in proper order:** This is the function of the **starting air distributor** (or pilot air distributor) and the **main starting air valves**, which control the sequence and timing of starting air admission, not the lubrication system component. **D) actuate exhaust valves in the correct sequence:** On large two-stroke engines, exhaust valves are typically actuated by a **hydraulic or pneumatic system** controlled by the engine's camshaft or an electronic control system, often involving a dedicated hydraulic cylinder or valve drive mechanism, not the mechanical lubricator shown.

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