504 sample questions

Question 1

Areas to Inspect on Engine Bedplates for Cracking

Answer 1

Critical areas include:
Welds joining transverse girders to longitudinals.
Under bearing pockets (radial cracks or along the pocket line).
Causes: Faulty manufacturing, uneven/overloading, loose tie bolts or holding down bolts
.

Question 2

Purpose of the Entablature

Answer 2

Houses pistons and liners.
Contains cooling channels for jacket cooling.
Contains the scavenge space of the engine

Question 3

Purpose of Engine Tie Bolts (with Sketch)

Answer 3

Hold entablature, A-frames, and bedplates together in compression.
Transfer firing loads to the bedplate.
Reduce engine weight while allowing high power output
.

Question 4

Issues if Tie Bolts Work Loose

Answer 4

Fretting (visible as red oxide paste).
Increased stress on rods, risk of rod failure.
Misalignment and potential cracking in transverse girders

Question 5

Problems Associated with Tie Bolts

Answer 5

Can work loose.
Can break.
Cause fretting and misalignment.
Can lead to cracking of transverse girders

Question 6

Two Materials Used for Engine Chocks

Answer 6

Cast Iron or Steel.
Resin-based materials

Question 7

Stresses a Cylinder Liner Must Withstand

Answer 7

Hoop Stress: Due to internal gas pressure.
Thermal Stress: From temperature gradients between hot combustion and cooler water jacket.
The liner must manage compressive stress on the hot side and tensile stress on the water side

Question 7

Reasons for Using End Chocking

Answer 7

Prevent axial movement of the engine.
Transmit thrust to the ship’s structure

Question 8

Two Materials Used for Cylinder Liners

Answer 8

Cast iron alloyed with chromium, vanadium, molybdenum.
Spheroidal (nodular) graphite iron

Question 9

Why Cylinder Liner Cooling is Vital

Answer 9

prevent overheating and cracking.
Controls thermal stress.
Maintains mechanical strength at high temperatures
.

Question 10

Causes of Abnormal Wear &Details on Two Causes

Answer 10

Frictional wear.
Corrosion.
Abrasion.
Micro-seizure

Corrosion: Due to sulphur in fuel forming acid, especially if water jacket temperature is low.
Frictional Wear: Influenced by lubrication efficiency, piston speed, ring condition, and combustion quality

Question 11

Cloverleafing

Answer 11

Irregular corrosive wear between quills due to poor oil neutralisation.

Appears as cloverleaf-shaped wear patterns causing ring collapse

Question 12

Effects of Over/Under Lubrication

Answer 12

Over-lubrication: Increases scavenge fire risk, oil clogging, excessive consumption.
Under-lubrication: Micro-seizure, increased wear, blow-by, scavenge fires

Question 13

Gauging a Cylinder Liner

Answer 13

Use micrometer with extension bar calibrated against a master gauge.
Liner should be cleaned; ideally measured cold.
Gauging checks liner wear over time

Question 14

Crankshaft Function and Stresses

Answer 14

Converts reciprocating motion to rotary motion.
Transmits engine pressure.
Subject to bending, torsional, and shear stresses

Question 15

Five Occasions for Taking Crankshaft Deflections

Answer 15

After grounding.
Suspected misalignment.
Post-overhaul.
High bearing temperature.
Periodic maintenance

Question 16

Preparations Before Crankshaft Deflections

Answer 16

Allow engine to cool.
Ensure vessel is on even keel.
Disconnect turning gear.
Rotate crankshaft manually to measurement positions.

Question 17

Issue with crankshaft deflections at BDC and Solution

Answer 17

Accessing the crank web at BDC is difficult.
Solution: Use mirror/angled measuring tools or avoid direct BDC; measure near it then interpolate values

Question 18

Purpose of Piston Rod Stuffing Box

Answer 18

Prevent cross-contamination of crankcase and scavenge space.
Scrape oil and seal pressure

Question 19

Sketch and Label: Stuffing Box Cross-Section

Answer 19

draw it you noobs

Question 20

Three Contamination Sources from Leaking Stuffing Box

Answer 20

Scavenge air: May enter crankcase, increasing pressure.

Lubricating oil: May leak into scavenge, causing fires.

Combustion gases: Risk of crankcase explosion

Question 21

Running Gear Survey Periodicity

Answer 21

Typically at major overhauls or drydock, guided by class or manufacturer (e.g., every 5 years or 12,000–15,000 hrs for bolts)
.

Question 22

Pros and Cons of Camshaft Chain Drives

Answer 22

Pros: Low weight, low cost, high placement, reduced damage from foreign particles.
Cons: Chain elongation, noise (polygon effect), timing drift, requires tension checks
.

Question 22

Requirements for Chief Engineers to Survey Equipment

Answer 22

Must meet classification society conditions.
Typically includes:
Proper records.
Training and certification.
Adherence to survey procedures

Question 23

Effects of Worn or Poorly Fitted Camshaft Chain

Answer 23

Incorrect timing. Valve/pump operation issues. Vibration and component wear/failure

Question 24

Exhaust Valve Operational Life Determination

Answer 24

Based on: Disc surface burn limits. Stem wear. Seat grinding limits

Question 25

Why Medium Speed Engines Use Two Valve Springs

Answer 25

One acts as fail-safe. Different frequencies reduce resonance risk

Question 26

Three Methods of Exhaust Valve Rotation

Answer 26

Rotocap. Turnomat. Air spring with integrated rotation mechanism

Question 28

Two Reasons to Rotate Exhaust Valves

Answer 28

Even out wear on valve and seat. Minimise deposit build-up