SAMS Propulsion and Machinery Systems 3

Question 1

What does the term 'propeller slip' refer to in marine propulsion?

Accepted Answer

The difference between theoretical and actual advance per revolution

Answer

Propeller slip is the difference between the theoretical pitch distance the propeller should advance per revolution and the actual distance traveled through the water.

Question 2

A surveyor notes that a vessel's inboard engine raw water cooling pump impeller is made of nitrile rubber. What inspection finding would indicate impeller failure is imminent?

Accepted Answer

Vanes show set (permanent curve), cracking, or missing pieces

Answer

A nitrile impeller with permanent vane set, cracks, or missing pieces is near failure and will rapidly cause engine overheating if not replaced.

Question 3

When evaluating a vessel with twin diesel engines and a common seawater intake manifold, what specific risk should a surveyor note?

Accepted Answer

Cross-flooding or loss of cooling water to both engines if the shared intake seacock fails

Answer

A shared seawater intake means a single seacock failure can simultaneously deprive both engines of cooling water, an important redundancy risk.

Question 4

What is the function of a cutless bearing in a propulsion system?

Accepted Answer

To support and center the propeller shaft at the strut or stern tube using water lubrication

Answer

A cutless bearing is a rubber-lined, water-lubricated bearing that supports the propeller shaft at the strut and maintains shaft alignment.

Question 5

A surveyor observes that a marine gas turbine vessel has an intake plenum with visible salt crystal deposits. What operational problem does this indicate?

Accepted Answer

Failure of the intake air filtration and washing system

Answer

Salt deposits in the intake plenum indicate the air filtration or anti-icing/wash system has failed, allowing corrosive salt-laden air to reach the compressor.

(SAMS) Society of Accredited Marine Surveyors Certified Practice Test

(SAMS) Society of Accredited Marine Surveyors Certified Practice Test

SAMS Propulsion and Machinery Systems 3