In this post I have discussed the questions that
were asked in the Class 4B exam of MMD exam. This is the part 8 of
series dealing with the Marine engineering practice. Answer to these questions
will be available shortly. It is very important to have a look of the
questions that are asked in the previous year’s exam papers. If you have any
suggestions related to these questions, please write in the comment box below
this article. Previous year MMD exam papers are available for other subjects
also in our site.
were asked in the Class 4B exam of MMD exam. This is the part 8 of
series dealing with the Marine engineering practice. Answer to these questions
will be available shortly. It is very important to have a look of the
questions that are asked in the previous year’s exam papers. If you have any
suggestions related to these questions, please write in the comment box below
this article. Previous year MMD exam papers are available for other subjects
also in our site.
Function: Maintenance & Repair at Management Level
Marine engineering practice for Class 4B MMD exam- Part 8
1. With
reference to alkaline batteries used on board ship, state:
reference to alkaline batteries used on board ship, state:
(a)
The significance of the specific gravity reading of the
electrolyte;
The significance of the specific gravity reading of the
electrolyte;
(b)
When the electrolyte would normally be renewed;
When the electrolyte would normally be renewed;
(c)
The reasons why the voltage reading of this type of
battery is not necessarily indicative of its condition;
The reasons why the voltage reading of this type of
battery is not necessarily indicative of its condition;
(d)
The normal temperature range for correct operation of a
battery and the safe upper temperature limit;
The normal temperature range for correct operation of a
battery and the safe upper temperature limit;
(e)
The effects of high and low temperatures.
The effects of high and low temperatures.
2. With
reference to the automatic combustion system for an auxiliary boiler describe
in detail how all safety checks
are carried out.
reference to the automatic combustion system for an auxiliary boiler describe
in detail how all safety checks
are carried out.
3. (a)
Describe the operating mechanism for a watertight door, which has provision for
remote closure from the bridge and local operation.
Describe the operating mechanism for a watertight door, which has provision for
remote closure from the bridge and local operation.
(b) State
the source of power for closure of electrical and the source of power for alarm
and indicator.
the source of power for closure of electrical and the source of power for alarm
and indicator.
4. Explain
the consequences of operating an engine with:
the consequences of operating an engine with:
(i)
Restricted air inlet passageway.
Restricted air inlet passageway.
(ii)
Restricted exhaust passageway.
Restricted exhaust passageway.
5. With
respect to main condensers using the shipboard instrumentation state, with
reasons, how the following would be detected:
respect to main condensers using the shipboard instrumentation state, with
reasons, how the following would be detected:
(i) Air leakage;
(ii)
Accumulation of oil on steam side of tubes;
Accumulation of oil on steam side of tubes;
(iii)
Deposits accumulation on waterside of tubes.
Deposits accumulation on waterside of tubes.
6. (a)
Describe a method of removal of a fixed pitch propeller.
Describe a method of removal of a fixed pitch propeller.
(b) State why intense concentrate heat
should not be applied to propeller bosses.
should not be applied to propeller bosses.
7. With
reference to mechanical / hydraulic governors explain:
reference to mechanical / hydraulic governors explain:
(a) Why
the flyweights are driven at a higher rotational speed than the engine.
the flyweights are driven at a higher rotational speed than the engine.
(b) How
dead band effects are reduced.
dead band effects are reduced.
(c) How
hunting is reduced.
hunting is reduced.
(d) How
the output torque is increased.
the output torque is increased.
8. With
reference to air compressors state why:
reference to air compressors state why:
(a)
Piston ring freedom and condition is important.
Piston ring freedom and condition is important.
(b)
Correct clearance volume is critical to performance.
Correct clearance volume is critical to performance.
(c)
Suction and delivery valves need to be maintained in
good working condition.
Suction and delivery valves need to be maintained in
good working condition.
(d)
Suction filters should be of large size and kept clean.
Suction filters should be of large size and kept clean.
9. The
flanges of a pump and motor are to be engaged with flexible coupling. Suggest
some coupling types which are in common use. State the materials of the
couplings used.
flanges of a pump and motor are to be engaged with flexible coupling. Suggest
some coupling types which are in common use. State the materials of the
couplings used.
10. Sketch any
two types of welds, widely used to join steel plates during construction of the
hull of a ship. State what would be the type of electrode used.
two types of welds, widely used to join steel plates during construction of the
hull of a ship. State what would be the type of electrode used.
1.
Suggest the most effective procedure of stopping a
number of pin hole leakages on a large main Sea Water pipe line without
stopping the line water under 7kg/cm2 pressure. The leakages are
over a large length of the pipe and in patches.
Suggest the most effective procedure of stopping a
number of pin hole leakages on a large main Sea Water pipe line without
stopping the line water under 7kg/cm2 pressure. The leakages are
over a large length of the pipe and in patches.
2.
Write short notes on the following:
Write short notes on the following:
(i)
Gauging o2 content in a oil tank
Gauging o2 content in a oil tank
(ii)
Gauging toxicity in a sewage tank
Gauging toxicity in a sewage tank
3.
Briefly describe a procedure of welding shipside plates
for a repair job of 1m2, stating types of weld used.
Briefly describe a procedure of welding shipside plates
for a repair job of 1m2, stating types of weld used.
4.
(a) In a radial piston pump, reversal and control of
fluid flow are accomplished by moving the _____________.
(a) In a radial piston pump, reversal and control of
fluid flow are accomplished by moving the _____________.
(i)
central valve
central valve
(ii)
radial plunger
radial plunger
(iii)
floating ring
floating ring
(iv)
cylinder body
cylinder body
(b) Briefly
Justify your option and state why the other options were not considered.
Justify your option and state why the other options were not considered.
5.
(a) One cause of leaky valves in a low pressure air
compressor may be attributed to _____________.
(a) One cause of leaky valves in a low pressure air
compressor may be attributed to _____________.
(i)
running with an air filter element different from that
required by the original manufacturer’s specifications
running with an air filter element different from that
required by the original manufacturer’s specifications
(ii)
excessive operating hours without carrying out
preventive maintenance
excessive operating hours without carrying out
preventive maintenance
(iii)
the compressor running too fast
the compressor running too fast
(iv)
excessive discharge pressure
excessive discharge pressure
(b) Briefly
Justify your option and state why the other options were not considered.
Justify your option and state why the other options were not considered.
6.
(a) A fluctuating and unsteady vacuum in an evaporator
may be caused by _____________.
(a) A fluctuating and unsteady vacuum in an evaporator
may be caused by _____________.
(i)
wet steam entering the air ejector nozzle
wet steam entering the air ejector nozzle
(ii)
pinhole leaks in the evaporator tube nests
pinhole leaks in the evaporator tube nests
(iii)
rapid scaling on the evaporator tube nests
rapid scaling on the evaporator tube nests
(iv)
high water levels in the last effect
high water levels in the last effect
(b) Briefly Justify your option and state why the other options were
not considered.
not considered.
7.
(a) A grease lubricated ball bearing or roller bearing
will run cooler if the grease _____________.
(a) A grease lubricated ball bearing or roller bearing
will run cooler if the grease _____________.
(i)
fills only 10% of all void spaces within the bearing
fills only 10% of all void spaces within the bearing
(ii)
has a high grease penetration number (is hard)
has a high grease penetration number (is hard)
(iii)
is thinned with a suitable lubricating oil
is thinned with a suitable lubricating oil
(iv)
is heated prior to packing the bearing
is heated prior to packing the bearing
(b) Briefly
Justify your option and state why the other options were not considered.
Justify your option and state why the other options were not considered.
8.
(a) The gasket and the broken studs have been replaced
on a tank manhole cover. Which of the following methods is satisfactory for
testing the repair?
(a) The gasket and the broken studs have been replaced
on a tank manhole cover. Which of the following methods is satisfactory for
testing the repair?
(i)
Pressurize the tank with 10 psig air, soap the repaired
area, watch for visible signs of leakage or bubbles.
Pressurize the tank with 10 psig air, soap the repaired
area, watch for visible signs of leakage or bubbles.
(ii)
Fill the tank with water via the ballast pump until the
innage reading corresponds to the maximum depth of the tank.
Fill the tank with water via the ballast pump until the
innage reading corresponds to the maximum depth of the tank.
(iii)
Hose test the repaired area with a minimum of 7kg/cm2
water pressure.
Hose test the repaired area with a minimum of 7kg/cm2
water pressure.
(iv)
Fill the tank via the ballast pump until water flows
from the vent line opening on deck.
Fill the tank via the ballast pump until water flows
from the vent line opening on deck.
(b) Briefly
Justify your option and state why the other options were not considered.
Justify your option and state why the other options were not considered.
9.
(a) In reference to air conditioning, when air attains
the maximum amount of moisture it can hold at a specific temperature, it is
said to be _____________.
(a) In reference to air conditioning, when air attains
the maximum amount of moisture it can hold at a specific temperature, it is
said to be _____________.
(i)
superheated
superheated
(ii)
saturated
saturated
(iii)
condensed
condensed
(iv)
convected
convected
(b) Briefly
Justify your option and state why the other options were not considered.
Justify your option and state why the other options were not considered.
10. (a)
Why are removable sleeves installed on centrifugal pump shafts?
Why are removable sleeves installed on centrifugal pump shafts?
(i)
They make it easier to replace the pump shaft packing.
They make it easier to replace the pump shaft packing.
(ii)
They can be economically replaced as they wear out.
They can be economically replaced as they wear out.
(iii)
They can be removed when it is necessary to lighten the
weight of the pump.
They can be removed when it is necessary to lighten the
weight of the pump.
(iv)
They increase the strength of the shaft.
They increase the strength of the shaft.
(b) Briefly Justify
your option and state why the other options were not considered.
your option and state why the other options were not considered.
1. Suggest
a repair procedure for a pitted pump shaft mainly in the areas of sleeve and
wear ring. Since no replacements possible.
a repair procedure for a pitted pump shaft mainly in the areas of sleeve and
wear ring. Since no replacements possible.
2. Write
short notes on the following:
short notes on the following:
A. Ultrasonic
testing methods
testing methods
B. Magnetic
particle detection tests
particle detection tests
3. Tubing
is sized by _______________________.
is sized by _______________________.
A. allowed
working pressure
working pressure
B. cross-section
area
area
C. nominal
inside diameter
inside diameter
D. nominal
outside diameter
outside diameter
Briefly Justify Your Answer
4. Short
cycling of a refrigeration compressor refers to _____________.
cycling of a refrigeration compressor refers to _____________.
A. frequently
grounding out
grounding out
B. frequently
starting and stopping
starting and stopping
C. running
too fast
too fast
D. running
too slow
too slow
Briefly Justify Your Answer
5. The
emergency bilge suction valve is typically used _____________.
emergency bilge suction valve is typically used _____________.
A. to
inject cleaning additives when the bilges are extremely dirty
inject cleaning additives when the bilges are extremely dirty
B. when
the main condenser becomes fouled, in order to provide additional cooling water
circulation
the main condenser becomes fouled, in order to provide additional cooling water
circulation
C. to
connect the rose box to the independent bilge suction
connect the rose box to the independent bilge suction
D. if
the bilges become flooded and they can not be emptied by any other means
the bilges become flooded and they can not be emptied by any other means
Briefly Justify Your Answer
6. The
by-products of oxidation, as a result of water contamination of hydraulic oil,
are generally ____________.
by-products of oxidation, as a result of water contamination of hydraulic oil,
are generally ____________.
A. removed
by cellulose type filters
by cellulose type filters
B. gums,
varnishes, and acids
varnishes, and acids
C. always
neutralized by oil additives
neutralized by oil additives
D. harmless
and have no effect on system components
and have no effect on system components
Briefly Justify Your Answer
7. A
high reading at a salinity cell located in the loop seal between two stages of
a flash type evaporator would indicate __________.
high reading at a salinity cell located in the loop seal between two stages of
a flash type evaporator would indicate __________.
A. chill
shocking is necessary to remove scale
shocking is necessary to remove scale
B. leakage
at the second-stage condenser
at the second-stage condenser
C. faulty
operation of the brine overboard pump
operation of the brine overboard pump
D. carryover
in the first-stage
in the first-stage
Briefly Justify Your Answer
8. Which
of the following statements represents the proper relative direction of flow
through a globe valve?
of the following statements represents the proper relative direction of flow
through a globe valve?
A. Direction
of flow through the valve is unimportant.
of flow through the valve is unimportant.
B. Direction
of flow through the valve depends upon the type of seat design used in the
valve.
of flow through the valve depends upon the type of seat design used in the
valve.
C. Direction
of flow should be from below the seat.
of flow should be from below the seat.
D. Direction
of flow should be from above the seat.
of flow should be from above the seat.
Briefly Justify Your Answer
9. Which
of the listed types steam traps operates on the principle that hot water
flashes to steam when its vapor pressure is rapidly reduced?
of the listed types steam traps operates on the principle that hot water
flashes to steam when its vapor pressure is rapidly reduced?
A. Ball
float
float
B. Thermostatic
C. Bimetallic
D. Impulse
Briefly Justify Your Answer
10. A squealing
sound occurring from within an operating reciprocating air compressor is an
indication of __________.
sound occurring from within an operating reciprocating air compressor is an
indication of __________.
A. compressor
overload
overload
B. motor
overload
overload
C. tight
compressor bearings
compressor bearings
D. badly
leaking unloaders
leaking unloaders
Briefly Justify Your Answer
1.
The Fresh Water transfer pump on board your ship, has
gradually stopped taking suction from the Fresh Water tanks. Write a letter to
the owner / manager stating the parts of the pump you suspect are either worn
out or broken.
The Fresh Water transfer pump on board your ship, has
gradually stopped taking suction from the Fresh Water tanks. Write a letter to
the owner / manager stating the parts of the pump you suspect are either worn
out or broken.
2.
The flanges of a pump and motor engaged with flexible
coupling are always misaligned resulting in regular coupling failure. Suggest
proper installation and alignment procedures to avoid such a problem.
The flanges of a pump and motor engaged with flexible
coupling are always misaligned resulting in regular coupling failure. Suggest
proper installation and alignment procedures to avoid such a problem.
3. Sketch
any two types of welds, widely used to join steel plates during construction of
the hull of a ship. State what would be the type of electrode used.
any two types of welds, widely used to join steel plates during construction of
the hull of a ship. State what would be the type of electrode used.
4.
The exposed portion of the outboard propeller shaft is
protected against seawater corrosion by ________________.
The exposed portion of the outboard propeller shaft is
protected against seawater corrosion by ________________.
(a)
a heavy lubricant
a heavy lubricant
(b)
a covering of plastic, rubber, or shrunk-on composition
sleeve
a covering of plastic, rubber, or shrunk-on composition
sleeve
(c)
a corrosion-resistant paint
a corrosion-resistant paint
(d)
a layer of oxidation formed when the metal of the shaft
is exposed to seawater
a layer of oxidation formed when the metal of the shaft
is exposed to seawater
5.
Why are removable sleeves installed on centrifugal pump
shafts?
Why are removable sleeves installed on centrifugal pump
shafts?
(a)
They make it easier to replace the pump shaft packing.
They make it easier to replace the pump shaft packing.
(b)
They can be economically replaced as they wear out.
They can be economically replaced as they wear out.
(c)
They can be removed when it is necessary to lighten the
weight of the pump.
They can be removed when it is necessary to lighten the
weight of the pump.
(d)
They increase the strength of the shaft.
They increase the strength of the shaft.
Briefly
Justify your Answer
Justify your Answer
6.
If a reciprocating air compressor has a knock occurring
in frequency with its operating RPM, the cause is probably ____________.
If a reciprocating air compressor has a knock occurring
in frequency with its operating RPM, the cause is probably ____________.
(a)
misalignment or worn main bearings
misalignment or worn main bearings
(b)
insufficient cylinder lubrication
insufficient cylinder lubrication
(c)
defective or poorly fitted valves
defective or poorly fitted valves
(d)
all of the above
all of the above
Briefly
Justify your Answer
Justify your Answer
7.
Which of the following clearance readings should be
taken and recorded in drydock?
Which of the following clearance readings should be
taken and recorded in drydock?
(a)
The clearances between the propeller blade tips and the
hull.
The clearances between the propeller blade tips and the
hull.
(b)
The clearances between the propeller hub and the fair
water cone.
The clearances between the propeller hub and the fair
water cone.
(c)
The rudder bearing clearances.
The rudder bearing clearances.
(d)
The clearances between the stern tube packing gland and
the retaining ring.
The clearances between the stern tube packing gland and
the retaining ring.
Briefly
Justify your Answer
Justify your Answer
8. A
small ship side over board discharge valve appears to be leaking sea water
apparently because of corosion or a crack in its body. (a) Suggest some
measures you would propose to the second engineer to rectify the leakage. (b)
Concurrently the fitter on your ship comes up with a brand new equivalent valve
and suggests to replace it immediately. What specific conditions you would look
for to even attempt such a repair?
small ship side over board discharge valve appears to be leaking sea water
apparently because of corosion or a crack in its body. (a) Suggest some
measures you would propose to the second engineer to rectify the leakage. (b)
Concurrently the fitter on your ship comes up with a brand new equivalent valve
and suggests to replace it immediately. What specific conditions you would look
for to even attempt such a repair?
9. The
propeller shaft of a lifeboat makes a horrendous noise, whenever the engine is
tried out. What in your opinion could be the possible reasons of this noise and
suggest some corrective measures for causes which in your opinion creates this
noise.
propeller shaft of a lifeboat makes a horrendous noise, whenever the engine is
tried out. What in your opinion could be the possible reasons of this noise and
suggest some corrective measures for causes which in your opinion creates this
noise.
10. A portable
aluminium alloy air cylinder of a SCBA
is leaking from its body. You are aware, by literature of methods and
innumerable means of repairing it
aluminium alloy air cylinder of a SCBA
is leaking from its body. You are aware, by literature of methods and
innumerable means of repairing it
(a) suggest
what type of innovative repair procedures you would adopt on board
what type of innovative repair procedures you would adopt on board
(b) alternatively,
you have a choice of discarding it and going
in for a new one already available on board. Which one of the options
would you exercise and why.
you have a choice of discarding it and going
in for a new one already available on board. Which one of the options
would you exercise and why.
(c) are
there any means of testing such bottles on board.
there any means of testing such bottles on board.
