Question 69 DDE01 - Designated Duty Engineer - Unlimited HP

The Correct Answer is C **Explanation of why option C is correct:** The fault description states that the **astern clutch fails to engage from all control locations**, but the **ahead clutch properly engages from all control locations**. 1. **Failure from All Locations:** If a fault is common to all control stations (Engine Room, Bridge, etc.), the fault must lie downstream of where the control signals converge or at a component shared by all control systems. 2. **Clutch Control Panel (CPP) / 4-way Control Valve:** The 4-way control valve (or the Clutch Control Panel) is the central hydraulic/pneumatic switching component that physically directs the high-pressure air (or oil) to the clutch actuator based on the remote pilot signals received from the control stations. This component handles both ahead and astern engagement signals. 3. **Specific Failure (Astern Only):** If the ahead function works perfectly, the main air supply, the ahead pilot system, and the physical ahead clutch mechanism are all functional. 4. **Astern Pilot Tubing Separation:** If the astern pilot air tubing separates from the 4-way control valve (or the corresponding astern input port) at this central location, the astern pilot signal (pressure) sent from *any* control station will simply leak to atmosphere instead of reaching the 4-way valve. Consequently, the 4-way valve will never switch into the astern position, and the astern clutch will fail to engage, regardless of which station is attempting control. **Explanation of why the other options are incorrect:** * **A) The ahead clutch engagement pilot air tubing has separated from the clutch actuator 4-way control valve at the clutch control panel.** This is incorrect because the symptom explicitly states that the **ahead clutch properly engages**. If the ahead pilot tubing had separated, the ahead clutch would fail to engage, contradicting the observed symptoms. * **B) The control lever at the pneumatic remote-control station has a blocked astern clutch engagement pilot port.** This is incorrect because the symptom states the astern clutch fails to engage **from all control locations**. If only the remote-control station (Bridge) had a blocked port, the astern clutch would still engage properly when commanded from the Engine Room control station. * **D) The control lever at the engine room control station has a blocked astern clutch engagement pilot port.** This is incorrect for the same reason as B. If only the Engine Room station had a fault, the astern clutch would still engage properly when commanded from the pneumatic remote-control station (Bridge). The fault must be common to, and downstream of, all control stations.