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

Normal wear from extended operation

Answer

Excessive shaft alignment error only

Answer

Thermal expansion from overheating exhaust

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

Intercooler efficiency

Answer

Fuel injector spray pattern

Answer

Exhaust manifold backpressure

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

To dampen vibration between shaft and hull

Answer

To lubricate the propeller shaft bearings

Answer

To maintain propeller pitch angle

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

A starboard fuel injector is partially blocked

Answer

The governor is malfunctioning under load

Answer

Transmission fluid is overheating

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

The engine is running at optimal load

Answer

Excessive fuel enrichment at idle

Answer

The raw water pump is overperforming

Question 6

A surveyor finds bronze through-hull fittings adjacent to the aluminum stern drive. What corrosion concern should be documented?

Accepted Answer

Galvanic corrosion due to dissimilar metals in an electrolyte

Answer

Crevice corrosion from the bronze fitting threads

Answer

Stray current corrosion from the raw water pump

Answer

Intergranular corrosion of the aluminum casting only

Question 7

Which condition would a surveyor most expect to find associated with a cavitating propeller?

Accepted Answer

Erosion pitting on the suction face of the blades near the tips

Answer

Smooth leading edges with uniform pitch

Answer

Even thinning of blade trailing edges from abrasion

Answer

Increased propeller diameter from metal deposition