Marine engineering knowledge previous year questions paper for Class 4B MMD exam- Part 5

1.
During your watch one of the main engine unit was
indicating high exhaust temperature reading. Write a note to Chief Engineer
explaining:

(a)
how the cause leading to abnormal running condition was
diagnosed

(b)
subsequent action taken to control the fire.

2. State
FOUR operational conditions that may lead to vibration of the main transmission
shafting.

3. What
are the main advantages of the impulse and the constant pressure exhaust
turbo-charging systems?

4. Explain
how sluggish action of the suction and delivery valves reduces the volumetric
efficiency of an air compressor.

5. (a) Make a detailed sketch of a tilting pad type
thrust block.

6. With
respect of hydraulic ram type steering gear:

(a) State
the emergency locking device that can be used in order to speedily bring the
steering gear to rest:

(b) State,
with one reason the best angular position to lock the steering gear in.

7. The
reading of the steam pressure gauge of an auxiliary boiler is suspect.
Describe:

(a) The
action to be taken

(b) How the gauge could be calibrated

8. (a)
Sketch a cascade control system.

(b)
Explain the operation of this cascade system.

9. In
any diesel engine closed freshwater cooling system, the lowest pressure exists
at the _____________.

(a)
jacket water outlet

(b)
cooling water pump outlet

(c)
heat exchanger outlet

(d)
expansion tank atmospheric vent

Briefly Justify
Your Answer

10. The
main advantage of unit injectors over other fuel injection
systems is _____________.

(a)
Reducing the need of too many high pressure fuel lines

(b)
their relatively low injection pressures

(c)
reduced wear of spray orifices

(d)
the lessened chance of fuel leaks into the engine sump

Briefly Justify your Answer

1.
Write
an Instructional note (about 500 Words) to your support crew, who are just
about to decarbonize a generator, on the need to ensure safe practices during
the overhaul.

2.
Sketch
and describe a Main Engine expansion tank (Compensating Tank) fitted on the
Jacket cooling water system.

3.
Sketch
and describe a main air starting valve, fitted to a Large Two Stroke Marine
Diesel Engine used for main propulsion.

4.
Write Short
Notes on the Following:

A. Mixing Columns

B. Main Sea
Suction Chest and Filter

5.
Lubrication for the main reduction gears used with
diesel engines is usually supplied by _____________.

A.
oil from the main engine sump

B.
an independent lube oil system

C.
the stern bearing head tank

D.
the stern bearing sump tank

Briefly Justify
Your Answer

6.
Excessive vibration of an automatically fired auxiliary
boiler can be caused by _____________.

A.
air or water in the furnace

B.
combustion pulses

C.
fuel oil pump failure

D.
flame failure

Briefly Justify
Your Answer

7.
Cooling the intake air supplied to a diesel engine will
_____________.

A.
reduce mean effective pressure

B.
decrease average compression pressure

C.
decrease air charge density

D.
increase power output
Briefly
Justify Your Answer

8.
Which of the listed items should be secured before performing any maintenance on a solenoid operated
air start valve?

A.
Electric power

B.
Lube oil standby pump

C.
Hydraulic switch

D.
Motor drain

E.
Main
switch board busbar

F.
Emergency
switch board circuit breaker.

G.
The
AV Regulator

Briefly Justify
Your Answer

9.
The purpose of a temperature sensing device installed
in the stack of a small automatically fired auxiliary steam boiler is to secure
the oil burner _______________.

A.
in the event of a flame failure

B.
in the event of a stack fire

C.
when the water level reaches the crown sheet

D.when the feed pump discharge pressure drops to a preset
minimum Briefly
Justify Your Answer

10. What
is to be installed on an internal combustion engine if its cylinder bore exceeds
200mm?

A.
Crankcase vapor monitors

B.
Engine exhaust silencers

C.
Constant pressure type turbochargers

D.
Explosion relief valves

E.
Heat
resisting, anticorrosive paint

F.
Vibration
dampers

G.
Engine
failure alarms

Briefly
Justify Your Answer

1. (a) Describe
with sketches an axial flow pump;

(b) State the
important advantage and the serious disadvantage it possesses compared to other
pumps;

(c)Explain the
effects of throttling either the suction or the discharge valve.

2. Give
the outline sketch of a piston cooling water system of a large 2-stroke marine
diesel engine, stating the means of replenshing the water.

3. (a) State, with reasons, THREE properties
required of a crankcase oil which is to be used for a trunk piston main engine.

(b) Explain
how a representative sample of crankcase oil would be obtained from a trunk
piston engine.

4. A set of fuel injectors along with their
needle and guide for an auxiliary engine of 500kw capacity is air freighted to
your ship, completely packed and sealed at the manufactures site. Give a step
by step method of how you would make such an injector ready for installation on
the engine.

5.
Sketch
and describe the valve operating mechanism for a four-stroke auxiliary Diesel engine.
Explain how the valves are set and sketch a timing diagram for the engine.
State the effects on engine operation if the initial clearances were
appreciably lower or greater respectively than those recommended by the engine
makers.

6.
List
the equipment required and describe completely the operation of removing the
connecting rod of a main Diesel engine.

7.
State
the causes of excessive cylinder liner wear in compression-ignition
engines. In what part of the liner does
the greatest wear take place and why does it occur there? , Explain the
possible consequences of operating an engine with excessive wear of a cylinder.

8. If
the combustion control system of an automatically fired auxiliary boiler fails
to restart from the normal shutdown mode, you should check for ______________.

(A)
broken or grounded high tension leads

(B)
a faulty ignition cable connector

(C)
an incorrect electrode setting

(D)
all of the above

Briefly Justify your Answer

9.
When taking tank
soundings on a ship, coating the tape with chalk helps to ______________.

(A)
better identify the correct reading

(B)
show the depth of any water in an oil tank

(C)
make the tape roll easier

(D)
reduce possibility of sparks

Briefly
Justify your Answer

1. Discuss the importance of following
characteristics of lubricating oil used in low and

medium speed diesel engines :-

(a)
Dispersants

(b)
detergent

(c)
acid neutralization

(d)
anti-oxidation

(a) Increase
fuel to the engine.

(b) Open
exhaust gas boiler by pass.

(c) Clean
air filter.

(a)
Why flyweights are driven at a higher rotational speed than the engine.

(b)
How dead band effects are reduced

4. What types of bearing are used to support
the rotating elements of propulsion

reduction gearing?

(a)
jacket water outlet

(b)
cooling water
pump outlet

(c)
heat exchanger
outlet

(d)
expansion tank
atmospheric vent

6. (a)
Sketch and describe a turbocharger with a radial flow gas turbine
showing the

position of the bearings.

(b)
State the advantages of radial flow gas turbines.

7. In engine rooms that are operated under UMS
conditions describe with the aid of

sketches how
the following are monitored:

(a)
The perforation of a high pressure fuel pipe.

(b)
The imminence or possibility of a scavenge fire.

(c)
Condition that may be conducive to a crankcase
explosion.

8. (a)
State the aims of boiler water treatment.

(b) Describe FOUR tests that may be undertaken to
ascertain boiler water condition.

9. Explain why the effectiveness of crank case
diaphragm glands deteriorates in service.

Describe briefly how such glands are
overhauled.

10. Excessive vibration of an
automatically fired auxiliary boiler can be caused by

_____________.

(a)
air or water in
the furnace

(b)
combustion pulses

(c)
fuel oil pump failure

(d)
flame failure

1.
Indicator cards have shown that one cylinder is high in power although
the maximum pressure is low. State the associated effects that this might have
on the various instruments of the engine and give a detailed description of the
method of rectifying the defect. If this abnormality were not remedied, what
might be the subsequent effects on the operation of the engine? State the type
of engine to which your answer refers.

2.
With reference to turbochargers :

(a) Explain the term
surging, stating how it occurs, its effect on the turbocharger and how it can
be avoided;

(b) Describe the procedures
for cleaning EACH of the following and explain the precautions which should be
taken;

(i) Suction air filter,

(ii) Turbine blades and
nozzle ring

3.
With reference to diesel engine maintenance:

(a)
Describe the various means that are available to check
the condition of a diesel engine as a guide to when maintenance is actually
needed;

(b)
Compare the methods described in (a) with the use of planned maintenance schemes.

4.
Describe with a sketch an automatic combustion system for a auxiliary
boiler, also state how the system with its safety devices is tested for all
modes of operation.

5.
Which of the following statements describes the
function of an expansion tank in a diesel engine cooling system?

(a)
Maintains a constant head on the system.

(b)
Reduces the likelihood of air or steam pockets
formation.

(c)
Provides a low pressure point for the addition of
makeup cooling water.

(d)
All of the above.

Briefly Justify Your Answer

6.
(a) Sketch a
pneumatic operated diaphragm valve, as used for control of piston cooling water
temperature in large 2 stroke main propulsion engines and for the valve you
have drawn, state its ‘action’ and ‘fail-safe’ properties.

7.
In a diesel engine, late fuel injection is indicated by
black or gray exhaust smoke with ______________.

(a)
low firing pressure

(b)
low exhaust temperature

(c)
mechanical knock in each cylinder

(d)
fuel knock in each cylinder

Briefly
Justify your Answer

8.
With reference to cylinder head valves explain the
reason for the following details:

(a)
Detachable molybdenum steel seats,

(b)
Stellite deposits on seat faces,

(c)
Spinners on valve stems,

(d)
Springs in pairs, series or parallel.

9.
If the combustion control system of an automatically
fired auxiliary boiler fails to restart from the normal shutdown mode, you
should check for ______________.

(a)
broken or grounded high tension leads

(b)
a faulty ignition cable connector

(c)
an incorrect electrode setting

(d)
all of the above

Briefly Justify Your Answer

10.
One method of constructing large marine diesel engines
and reducing the total engine frame weight is through ___________.

(a)
casting interlocking components

(b)
welding plates to form sections for assembly

(c)
forging integral components

(d)
case hardening integral components

Briefly Justify Your Answer