SAMS Propulsion and Machinery Systems 2

Question 1

When inspecting a vessel's reduction gear, a marine surveyor notices pitting on gear teeth. What does this typically indicate?

Accepted Answer

Lubrication failure or contaminated gear oil

Answer

Pitting on gear teeth is a classic sign of lubrication failure or oil contamination, which prevents proper film formation between meshing surfaces.

Question 2

A diesel engine's turbocharger is producing an audible whine at elevated RPM. What should a surveyor check first?

Accepted Answer

Turbine and compressor blade condition and bearing wear

Answer

An abnormal whine from a turbocharger typically indicates worn bearings or damaged blades in the turbine or compressor section.

Question 3

What is the primary purpose of a shaft seal (stuffing box or lip seal) in a propulsion system?

Accepted Answer

To prevent seawater ingress into the vessel around the propeller shaft

Answer

A shaft seal prevents seawater from entering the vessel through the aperture where the propeller shaft penetrates the hull.

Question 4

During a sea trial, a surveyor observes that engine RPM drops when the vessel turns to starboard. This symptom most likely indicates:

Accepted Answer

Propeller cavitation or shaft misalignment exacerbated by hull loading in turns

Answer

RPM drop during turns often suggests propeller cavitation or shaft/strut misalignment that worsens when hull attitude changes in a turn.

Question 5

What does a high exhaust back pressure reading indicate in a marine diesel engine installation?

Accepted Answer

A restriction in the exhaust system such as a blocked muffler or collapsed hose

Answer

Elevated exhaust back pressure points to a restriction downstream of the engine, commonly a blocked wet muffler, kinked hose, or collapsed exhaust riser.

(SAMS) Society of Accredited Marine Surveyors Certified Practice Test

(SAMS) Society of Accredited Marine Surveyors Certified Practice Test

SAMS Propulsion and Machinery Systems 2