STCW Marine Engineering 4

Question 1

What is the STCW requirement for a Chief Engineer officer on a ship of 3,000 kW or more propulsion power?

Accepted Answer

STCW Certificate III/2 — Chief Engineer

Answer

STCW Regulation III/2 and Table A-III/2 specify the competence requirements for Chief Engineers on ships with 3,000 kW propulsion power or more.

Question 2

What does the term 'viscosity index' indicate about a lubricating oil?

Accepted Answer

How much its viscosity changes with temperature

Answer

A high viscosity index means the oil's viscosity changes relatively little between hot and cold temperatures, which is desirable for consistent lubrication.

Question 3

What is the primary purpose of the alpha-lubrication (pulse lubrication) system on a large slow-speed two-stroke engine?

Accepted Answer

To deliver cylinder oil precisely timed with piston movement to reduce consumption and reduce deposits

Answer

Electronically controlled pulse lubrication injects cylinder oil at the optimal moment in the stroke, reducing oil consumption and carbon deposits compared to constant-rate drip systems.

Question 4

Which of the following best describes the function of a freshwater generator (evaporator) aboard ship?

Accepted Answer

Uses waste heat from jacket water to evaporate seawater and produce freshwater by condensation

Answer

Most shipboard freshwater generators use engine jacket water heat under vacuum to evaporate seawater at low temperature, then condense the vapor to produce fresh water.

Question 5

What is the significance of the Total Base Number (TBN) of a cylinder lubricating oil?

Accepted Answer

It measures the oil's ability to neutralize acidic combustion products

Answer

TBN represents the alkaline reserve in the oil that neutralizes sulfuric and other acids formed during combustion, protecting cylinder liner surfaces from corrosion.

(STCW) Standards Certification and Watchkeeping for Seafarers Practice Test

(STCW) Standards Certification and Watchkeeping for Seafarers Practice Test

STCW Marine Engineering 4