Lube Oil Purifier.docx

Lube Oil Purifier
Lube oil does not wear out! However, its lubricating quality tends to deteriorate over
time due to contaminants such as dirt, sludge, metals, and water to name just a few.
There are many different ways to remove these contaminants, some being more
effective than others. Common methods include; strainers, filtration, settling tanks,
and centrifugal type purifiers.
In the centrifugal purification process, there are two common methods used. One
method is the batch purification process where all of the oil is removed from a
storage tank (sump, settler, etc.) by the purifier and is delivered cleaned to another
reservoir. This method is typically done on machinery that is not operating. The
other method is the continuous process where the centrifuge takes a portion of the
oil from a tank, cleans it, and recycles it back to the same tank. This method can be
used on operating equipment but is not as fast or efficient as the batch process.
Centrifuges can also be used as Separators or Clarifiers. Separators use a dam
ring or discharge ring and remove water as well as solids from the oil being purified.
The water is discharged from the purifier. A clarifier is used when the main
contaminant is sediments, and water does not need to be removed from a system.
Any small amounts of water that does enter the centrifuge will remain in the bowl
until it is cleaned.
Centrifugal purifiers as sometimes catagorized as disk-type or bowl-type purifiers
according to the shape and general arrangement of the centrifuge, and some purifiers
are self-cleaning, while others must be manually cleaned.
Aboard the Patriot State, we have a disk-type, non-self-cleaning purifier
manufactured by DeLaval, and used as a separator in the continuous process.
In a a disk-type purifier, a bowl shaped rotating element encases a stack of disks.
The bowl itself sits atop the vertical bowl spindle which is driven by a worm gear
and clutch assembly. The spindle and bearing absorbs the weight of the bowl
assembly. Once operating, the bowl spins at approximately 7500 rpm. As liquids and
sediments of different densities enter through the distributor (the inner most center
of the bowl housing) of the centrifuge, they are quickly separated by the tremendous
centrifugal force created by the velocity of the centrifuge, and also by the close
separation created by the shallow distances of the individual disks inside the bowl
housing. The clean oil travels up between the neck of the top disc and the tubular
shaft/distributor. If the centrifuge is operating as a separator, the water will discharge
out between the neck of the top disc and the discharge ring mounted at the uppermost
section of the bowl top. Sediment, sludge and other materials will be moved to the
inside of the bowl shell and will remain there till cleaned. It is important to note that
the size of the discharge ring must be properly matched for the density of the

lubricating oil to be purified. If you are to use the purifier to centrifuge other oils
with different specific gravities, a different discharge ring must be used for each.
Lube Oil Purifier Specifications
Manufacturer DeLaval
Model 65N-03
Capacity 300 GPM (250 SSU at 130 °F)
Outlet pump 25 psig
Suction lift 15" Hg
Motor 1 HP. 440 VAC, 3, 1800 rpm

Lube Oil Purifier Operation
The following procedure is used to start the lube oil purifier aboard the Patriot State.
1. All of the internal running parts of the purifier are automatically lubricated
by a mist or spray caused by the helical gear running in a reservoir of oil.
This reservoir must be checked and filed before operating the purifier. To
fill the reservoir, unscrew the filler cap (with dipstick) and pour oil into the
lube oil reservoir. It will take about 1 quarts of oil to completely fill the
reservoir. Make sure that the reservoir is not overfilled when done and also
make sure to replace the cap/dipstick. This should not be done while the
purifier is operating!
2. Check that the brake and lock screws have been released, open the purifier,
inspect, and make sure that the bowl is properly reassembled and that the
bowl revolves freely.
3. Clamp the cover and inlet arm down firmly
4. Open all valves for the discharge pump and the tank it supplying.
5. Open all valve for the suction pump and the tank its receiving
from except the inlet valve for the suction pump.
6. Start the pump and check for the speed by depressing the speed indicator.
The plunger should indicate not less than 70 times per minute..
7. Prime the bowl by adding water to the funnel at the top of the purifier. The
bowl is completely primed if water drains from the discharge port.
8. Open the inlet valve slowly. Maintain a discharge head of 6-8 psig.
9. The temperature of the lube oil should be maintained between 160-165° F.
The oil discharge port should be 1/8 full and the water discharge port should
have no oil in it and little or no water. (a large amount of water would
indicate water contamination of the oil being purified and should be
investigated.

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Direct comments to William Haynes whaynes@maritime.edu
Mon, Jul 1, 1996
TSPS Engineering Manual ©1995 Massachusetts Maritime

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HomeMarine EngineeringMarine Purifiers Principles of operation
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Marine Purifiers Principles of operation
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Fuel and Lubricants
1.
Draw a line diagram of a simple distillation process indicating the points at which kerosene,
gas oil, residual fuel, heavy gas oil and lubricating oil are fractioned off. (10)
2.
(a) What are the reasons for the deterioration in the quality of fuel supplied for use in marine
diesel engines.(2)

(b)Write short notes on the following fuel characteristics, Viscosity, Density, CCAI and
Calorific value (8)
3.
(a)Explain upper and lower flammable limit of hydrocarbon using a graph (7)
(b) Define classification of dangerous fuels by their flash point.(3)
4.
With respect to fuel characteristic used in internal combustion engines
1. Define ignition delay.(2)
2. Explain octane number and cetane number (8)
5.
(a)Describe the source of water contamination of fuel.(3)
(b) Describe the on board testing procedure for water in fuel (4)
(c) Discuss the effect of salt water contamination of fuel oil on engine.(3)
6.
(a) What are the likely consequences if fuel with excessive catalytic fines is used in an
engine.(8)
(b) What adjustment is required to remove this catalytic fines are more efficiently removed in
separators. (2)
7.
(a) Why fuel oil additives being used in fuel oil (4)
(b) Explain the harmful effect of having excessive sulphur, vanadium and catalytic fine in
bunker fuel. (6)
8.
(a) Draw and describe a oil filter module capable of removing water.(7)
(b) Describe the automatic back flushing process of the module.(3)
9.

Write down the key check points and documentation required in different stages of bunkering
, (a) Before bunker (2)
(b) During bunker (6)
(c) after bunker (2)
10.
(a) Explain the difference in use of the fine mesh filter with respect to coarse types. (2)
(b) Draw a Auto-Klean filter and describe the cleaning process including the particle size it is
capable of filtering out. (8)
11.
State the precautions to be taken against spillage during bunkering operations. ( 10)
12.
With reference to the treatment of lubricating or fuel oil:
a.State the function of a purifier;(2)
b.State the function of a clarifier;(2)
c.State TWO constructional differences found in the bowls of purifiers and clarifiers (6)
2.0 Pumps and pumping system
1.
(a) Sketch a lubricating oil pump and explain it’s operational procedure.(6)
(b) Identify the clearances critical to pump efficiency (2)
(c) Why a relief valve is needed? (2)
2.
(a) Sketch a centrifugal pump (5)
(b) Why such a pump may require a priming pump? (3)
(c) State two distinct characteristics that separates it from other pumps. (2)

3.
(a) Sketch a pump most suitable for lub oil circulation in a marine engine. (6)
(b) What is the function of the timing gear? (2)
(c) How axial thrust is managed with in acceptable limit in such a pump (2)
4.
(a) Draw and describe a constant speed, unidirectional, variable stroke, axial flow, rotary
positive displacement pump.(8)
(b) State 2 shipboard application of such a pump (2)
5.
With reference to self priming centrifugal pumps
(a) Sketch a liquid ring priming pump and describe how it operates? (7)
(b) Why all ER centrifugal pumps are not fitted with priming pump?(3)
6.
(a) Draw a line diagram of central priming system, label the principal items and show the
flow in all lines.(6)
(b) State the advantages and disadvantages the system has over individual priming equipment
(4)
7.
With respect to centrifugal sea water pumps
(a) Give four reasons why the output may reduce (6)
(b) If the pump vibrates occasionally, what could be the causes? (4)
8.
(a) Explain with suitable graph following characteristics of a centrifugal pump VS quantity
delivered. A) Discharge head b) NPSH c) input Power d) Efficiency (10)
9.
(a) Draw and describe a pump suitable for noxious chemical cargo discharge (7)
(b) State the need for two seals and the use of cofferdam between seals (3)

10.
(a) Sketch a double acting reciprocating pump with suitable valve assembly.(6)
(b) Describe the operation including the use of an accumulator. (4)
11.
With reference to Diesel engine driven emergency fire pumps
(a) Define their limitation as regards to suction lift, out put and jet distance (5)
(b) Explain how and why they are isolated from the main fire pumps (3)
(c) State two suitable locations for such a pump. (2)
12.
(a) Sketch and describe a centrifugal pump.(4)
(b) Why Relief valve is not fitted in above pump?(2)
(c) Identify the causes of cavitation in centrifugal pump.(4)
13.
(a) Sketch and describe a pump other than a centrifugal pump.(4)
(b) Why positive displacement pump is required relief valve but centrifugal pump doesn’t
require?(3)
(c) Centrifugal pump taking not taking suction, state three main reasons.(3)
14.
With respect to centrifugal pumps describe causes of followings.
(a)Pump not taking suction.(3)
(b)Pump fails to deliver liquid.(3)
(c)Pump doesn’t deliver at rated capacity.(4)
15.
With reference to centrifugal pumps:
(a) explain why large pumps should be started with the discharge valve closed; (6)
(b) state FOUR possible reasons for failing to achieve suction from a double bottom tank.(4)

16.
With reference to a steam heating coil in a fuel storage tank developing a leak:
a.State how the leak would be detected;(3)
b.State the immediate action to be taken when the leak is detected;(3)
c.Explain how the leak may be traced.(3)
17.
a.Describe, with the aid of a sketch, the bilge injection system (6)
b.State the purpose of fitting a bilge injection system on board a ship (4)
18.
a.Outline the separation process that occurs within centrifugal oil purifiers (5)
b.Describe the change required to the purifier if it is to be used for an oil of lower density(5)
19.
a.Outline the separation process that occurs within centrifugal oil purifiers (5)
b.Describe the change required to the purifier if it is to be used for an oil of very low quality
and high density (5)
20.
List EIGHT reasons why a bilge pump may not be able to remove water from an engine room
bilge.(10)
21.
With reference to centrifugal purifiers:
state the function of the gravity disc; explain the consequences of EACH of the following:
(i) gravity disc too large (5)
(ii) gravity disc too small (5)
3.0 Heat Exchangers

1.
With reference to multi tubular sea water coolers
(a) Sketch a two pass cooler showing the direction of fluid flow (5)
(b) Give two faults to which it is prone and how these faults are countered (5)
2.
With reference to multi tubular oil coolers describe
(a) Indications of tube leakage and locating procedure by tests. (6)
(b) temporaray and permanent corrective steps to stop leakage (4)
3.
(a) Explain how the following conditions contribute to the satisfactory performance of multi
tubular heat exchangers, i) Low tube thickness ii) cross flow iii) Baffle plates (6)
(b) Why it is of utmost importance that the division plate is intact and anodes are secured
properly. (4)
4.
(a) Describe with the aid of a diagram how a sea water circulatory system is subjected to
electrical current at a controlled rate.(7)
(b) State how in such a system the valves, pipes and coolers are protected. (3)
5.
(a) Sketch a plate type heat exchanger showing the sealing arrangements and flow directions.
(6)
(b) State the advantages and disadvantages of plate type heat exchanger over tube type. (4)
6.With reference to plate type heat exchangers, state why

(a) the plates carry a relief pattern (4)
(b) The carrying bars and clamping bolts are far longer than appears to be
Necessary (3)
(c) Pressure and temperature of fluids handled are restricted (3)
7.
With reference to evaporators and distillers
(a) Describe the function of demister.(2)
(b) Describe, with the aid of simple sketch, a low pressure evaporator which uses engines
heating medium.(8)
8.
(a) What is osmosis and reverse osmosis? (3)
(b) Describe with sketch, Reverse osmosis process. (7)
9.
With reference to evaporators and distillers
(a) Explain why low pressure evaporators are used? (3)
(b) Explain what is meant by single effect and double effect evaporation?(3)
(c) Describe, with the aid of simple sketch, a two stage flash evaporator.(4)
10.
(a) With the aid of diagram explain the working principle of a Evaporation type fresh water
Generator.(6)
(b) Why is it suggested not to drink the generated distillate water and when it is safe to use?
(4)

11.
1. a) Draw a line diagram of a central cooling system installed in cargo ship with the
principle components and showing the direction of flow in all lines. (3)
2. b) Explain the function of this arrangement.(3)
3. c) Give two advantages and two disadvantage of this system compared to the practice
of employing central cooling system for each service.(4)
12.
1. a) What is the function of wear ring? (4)
2. b) Draw a line diagram of central cooling system and explain its advantages and
disadvantages.(6)
13.
With reference to centrifugal separator
1. a) Differentiate between the purpose and operation of purifier and clarifier.(2)
2. b) Explain how these different roles are achieved? (4)
3. c) What are the factors need to be maintained for good purification process?(4)
14.
1. a) Explain the hazard of maintaining low quality of engine system oil in
circulation.(3)
2. b) If on passage you had reason to think that the lubricating oil in the main engine was
contaminated, Can you state any checks which would help you come to a conclusion
about the contamination. (7)
15.
1. a) Describe the regular systematic inspection of main air compressor, reservoir and
accessories.(5)
2. b) Identify common faults to which compressors and reservoirs are susceptible.(2)
3. c) Describe how these faults are prevented and rectified?(3)
4.0 Steering Gear
1.

(a) Explain the function of a hydraulic telemotor with the aid of a sketch. (5)
(b) Explain the charging system of the unit.(3)
(c) State how air in the system is detected and removed.(2)
2.
(a) Draw a line diagram of the hydraulic system for a Ram Steering gear, labelling the
principal items (6)
(b) Describe how the cushioning and relief arrangements function.( 4)
3.
With reference to ram steering gears explain
(a) the purpose of rapson slide and the mechanical advantage achieved (5)
(b) How a four ram gear can be operated with two rams in four combinations (5)
4.
(a) Sketch a hunting gear as fitted to a hydraulic steering gear, label it and explain how it
works both normally and in adverse weather condition.(7)
(b) Explain why relief valves are provided as well as shock valves in hydraulic steering gears.
(3)
5.
With reference to steering gears explain:
(a) Explain with diagram how Rudder is supported by the rudder carrier bearing and how the
conical shape of the bearing helps.(7)
(b) How limited amount of rudder drop is accommodated.(3)
6.
With reference to hydraulic steering gears, explain why:
(a) Telemotor receivers are spring loaded (5)
(b) Rudder movement is confined by the stops in the control systems(5)
7.
(a) Sketch a rotary vane steering gear and explain how it operates (7)

(b) Explain the advantages and disadvantages it possesses over Ram type.(3)
8.
(a) Describe the major rules and regulations regarding steering gear and how single failure
criteria rule is implemented. (8)
(b) State the difference between ‘follow up’ and ‘non follow up’ operation.(2)
9.
(a) Sketch a ward-Leonard all electrical steering system and explain how it works.(8)
(b) In case of unintentional rudder movement due to weather is corrected (2)
10. a) Describe with simple sketch, the principle of operation of axial piston pump used in
steering gear. (5)
11. b) Describe with the aid of simple sketch, how the pump is controlled to move the
rudder from one position to other. (5)
11.
1. a) Regarding steering gear what are the regulations extracts from SOLAS
convention?(4)
2. b) What do you mean by “FOLLOW UP” system?(3)
3. c) What do you mean by “NON-FOLLOW UP” system?(3)
12.
1. a) Sketch a hydraulic circuit of a two ram steering gear system mentioning the shock
relief and direction of flow for clockwise rotation of the rudder stock.(4)
2. b) Explain the advantages of “Rapson slide mechanism” incorporated in steering gear
system.(2)
3. c) Explain why excessive wear down of rudder carrier bearing is dangerous in ram
type steering gear? (2)
4. d) Explain how shocks to the system from wave action on rudder are absolved?(2)
13.
1. a) Draw a rotary vane steering gear? (4)
2. b) How does it work?(4)
3. c) Write one advantage and one disadvantage of ram type steering gear. (2)
14.

1. a) Sketch a hunting gear as fitted to a hydraulic steering gear labeling the principle
items. (6)
2. b) Explain the purpose of hunting gear.(4)
15.
Describe the procedure for testing a steering gear within 12 hours of sailing.(10)
16.
With reference to the testing of a ship’s steering gear, prior to departure, list EIGHT items of
machinery or control systems whose operation must be tested (10)
5.0 Oily Water Seperator/Sewage treatment plant/Ballast water Treatment Plant/Scubber
system
1.
With reference to oily water separators
1. Sketch and describe the operation of a two stage OWS.(6)
2. What is the principal of separation and how preheating is beneficial.(2)
3. What is the effect of varying degree of through put.(2)
2.
With reference to OWS
(a) Outline the routine attention needed to maintain satisfactory performance.(6)
(b) Define theadverse effect of cleaning chemical and turbulant flow in the performance(4)
3.
With reference to oily water separators explain why:
(a) Internal baffles are commonly fitted
(b) Coalescers are generally incorporated.
4.
Give reasons why each of the following conditions can result in bad performance of the
OWS,
(2.5 X 4)
1. i) high oil density

2. ii) high throughput
iii) turbulance and
1. iv) cleaning chemical
5.
(a) Sketch a 15ppm monitoring device fitted to Oily water separator discharge line and
explain it’s operation.(6)
(b) State the conditions that needs to be fulfilled before the operation of an approved
OWS.(4)
6.
With reference to oil content monitoring and control system:
(a) Explain with a sketch the operation of oil content monitoring system as fitted to the oil
tankers.(7)
(b) What are the signals at the calculating unit that is recorded.(3)
7.
(a) Sketch and describe the operation of a Biological Sewage treatment plant.(7)
(b) Define ‘BOD’ and ‘Colifor count’ (3)
8.
(a)Sketch and describe how a ‘zero discharge’ sewage treatment plant works. (6)
(b) Write the Marpol annex IV rules regarding discharge of sewage from ships(4)
9.
1. a) With the aid of sketch, Describe vacuum sewage system.(5)
2. b) State three advantages possessed by vacuum sewage system.(3)
3. c) Explain the term “coliform count”.(2)
10.
1. a) In oily separator, what type of pump is used, why centrifugal pump is not in use?(3)
2. b) What are the forces available in OWS? (2)
3. c) What are the safeties provided in OWS? (5)
11.

1. a) Describe with the aid of sketch, an aerobic STP. (5)
2. b) State the effect of, in any change in temperature and regularity of flow on the
system.(3)
3. c) Explain the significance of Biological Oxygen Demand (BOD) (2)
12.
1. a) Describe working principle of OWS.(3)
2. b) Give two reason why oil might be carried over with the water from an OWS? (2)
3. c) Outline the routine attention needed to maintain satisfactory performance of an
OWS. (2)
4. d) Define the contribution of test cocks towards functional efficiency.(3)
13.
Write presently available ballast water treatment systems. Describe any one Ballast Water
Treatment System with appropriate drawing.
14.
(a) What is SCR( Selective Catalytic Reduction)?
(b) Draw and label a SCR and briefly explain how it works.
15.
(a) How Sox is produced on board the ship? What is the present regulation? (b) Draw a Sox
scrubber plant and explain briefly.
16.
(a) With the help of diagram, describe in brief a biological type sewage treatment system.
(b) Why chlorination is necessary in this system?
27.
1. Describe the procedure for operating the oily water separator (5)
2. State TWO ways that the separator could be made to operate more efficiently (5)
7.0 Shafting System
1.
With reference to the thrust blocks state why,
(a) cooling coils are sometimes fitted in the sumps (3)

(b) axial clearance between collar and pads is minimal (4)
(c) They occasionally overheat (3)
2.
With reference to main thrust blocks:
(a) identify the critical clearances and state why they are critical.(3)
(b) describe with sketches how these clearances are adjusted.(4)
(c) give reasons why such bearings sometimes overheat although the clearances are adequate
(3)
3.
With reference to the transmission shaft coupling bolts state:
(a) why they are made a drive fit in the coupling holes.(3)
(b) why they are tightened to the limit of elasticity.(3)
(c) how couplings are assembled using “interference fit” boards.(4)
4.
With reference to the transmission shaft coupling bolts
(a) explain the conditions that causes fretting of main transmission shaft coupling bolts.(5)
(b) sketch and describe pilgrim bolt.( 5)
5.
With reference to propeller shaft couplings
(a) sketch and describe a coupling enabling external withdrawal of propeller shafts (7)
(b) state the advantages and disadvantages of this coupling compared to the solid flange
coupling.(3)
6.
With reference to the transmission shaft bearings:
(a) sketch a bearing carrying large diameter main transmission shafting and explain how the
bearing is lubricated and cooled.(7)
(b) give two reasons why such bearings occasionally overheat.(3)

7.
With reference to the stern tube sealing arrangements:
(a) sketch a sealing arrangement for an oil lubricated stern tube (aft) and explain how it
Works (6)
(b) state how oil loss due to seal failure can be restricted (4)
8.
With reference to the stern tube:
(a) draw an oil lubricated stern tube showing the seals forward and aft as well as the
bearings.(10)
9.
1. a) Draw and describe intermediate shaft and shaft bearing.
2. b) Suggest with reasons what remedial action should be taken upon arrival in port in
case of suspected uneven load on the shaft .
3. c) State the indications whilst at sea, that unequal loading of such bearing exist.
10.
State with a line diagram of two header tanks arrangement for the inboard oil seal and the
direction of oil circulation.
11.
(a) What are the purposes of putting a thrust bearing between the main engine and propeller?
(b) How is the thrust bearing cooled?
(c) Explain how does a variable pitch propeller operate?
(d) Describe how does the fail safe feature operate in controllable pitch propeller?
12.
1. a) Draw an oil sealing arrangement for stern tube aft and fwd seal.
2. b) Compare the advantages of above with water lubrication one.
13.
With reference to keyless propeller explain
(a) Why keys and keys ways have been eliminated?

(b) How is angular slip avoided?
(c) Draw & explain muff coupling.
14.
a.Describe the actions that the EOOW should take on finding that the temperature of the
thrust block is rising above normal acceptable range.(6)
b.Explain why the thrust block temperature is critical.(4)
8.0 Fire and Safety
1.
(a) Sketch a portable fire extinguisher suitable for oil fire, showing details of its triggering
mechanism, chemical composition and the details of hose. (7)
(b) Describe the strength and limitation of this extinguisher (3)
2.
In shipboard fire detection system, state
(a) Draw and describe an Ionisation type smoke detector (6)
(b) How tests are carried out on the different types of sensor heads (4)
3.
In shipboard fire detection system
(a) Use a suitable sketch to explain, how immediate warning is given in a sudden
conflagration and how a slow burning fire is detected.(8)
(b) Explain how false alarms can arise in (2)
4.
State why precautionary measures need to be taken in the following instances
(a) Entry into confined spaces, for example duct keel (4)
(b) Working in refrigerated spaces (3)
(c) Working in an emergency battery room (3)
5.
(a) Sketch and label a self contained breathing apparatus(4)

(b) State the precautionary measures taken on the SCBA set before entry into a confined
space (3)
(c ) State the safety feature of SCBA to warn wearer of low air pressure (3)
6.
With regards to bulk CO2 Fixed fire extingushing system
(a) Sketch a layout for a typical shipboard application. (4)
(b) State regulations that control capacity, quantity, and duration of discharge (3)
(c) State the advantage and limitations with battery CO2 system. (3)
7.
Concerning the CO2 total flooding fixed fire fighting installation:
(a) What checks would be made before operating the system (3)
(b) Draw a line diagram and explain the releasing operation.(5)
(c ) After discharge, how soon could re-entry be attempted (2)
8.
With regards to emergency fire pump
(a) What factors influence the location, operation and power requirements (3)
(b) Draw a fire main system and state the location of isolating valve and emergency fire
pump.(5)
(c ) Why drains are necessary on the deck main (2)
9.
(a) Sketch a sprinkler system state why it is considered as a detection and extingushing
combination system. (6)
(b) After such a system has been activated, how would it again be made ready for service? (4)
10.
Make a comparision of the benefits and limitations of the following installations for
shipboard machinery spaces.(10)
(a) High pressure water spray system

(b) CO2 total flooding system
(c ) Fixed foam smothering system
11.
(a) Sketch a fire detection control system and describe the main features (5)
(b) Sketch the switching mechanism to isolate air and fuel system powers before gang release
of CO2. Narrate its operation.(5)
12.
Compare with reasons the merits and demerits of the following permanent fire extinguisher
installed in machinery spaces
1. a) High pressure water spray
2. b) Carbon dioxide smothering
3. c) Chemical foam smothering
13.
State with reason, two types of fire extinguisher that may be used to fight a fire in each of the
following shipboard areas
1. a) Galley
2. b) Accommodation space
3. c) Machinery space control room
4. d) Main electrical switchboard
5. e) Paint locker.
14.
With reference to entry of personnel into enclosed spaces
1. a) State what minimum oxygen content in atmosphere within a space could be
considered safe.
2. b) Explain with the aid of sketch, the operation of an oxygen meter suitable for
checking the atmosphere within an enclosed space.
3. c) Explain the procedures to check the accuracy of the meter.
15.
1. a) How tests are carried out on the different types of sensor head?

2. b) Why mixed types of sensor are preferable in the engine room?
16.
State the safety checks needed before using EACH of the following lifting gear, assuming
that all certificates are in order and the equipment load capacity is sufficient for the lift:
a.wire strops;(5)
b.chain blocks;(5)
17.State the safety checks needed before using EACH of the following lifting gear, assuming
that all certificates are in order and the equipment load capacity is sufficient for the lift:
a.eye bolts (5)
b.shackles (5)
18.a.Describe the FOUR classes of fire indicating which fire fighting media should be used to
extinguish each.(4)
b.State the document that indicates the location of the fire extinguishers on board a vessel.(3)
c.State THREE places where the document stated in Q(b) would be found (3)
19. State, with a reason, TWO types of portable fire extinguisher that may be used to fight
a fire in EACH of the following shipboard areas: (5 X2)
20. Galley;
21. Accommodation space;
22. Machinery space control room;
23. Main electrical switchboard.
24. Dryer room.
20.
(a)State the meaning of the term enclosed space.(4)
(b) Explain the procedure for preparation for entry into a cofferdam prior to an ( 12)
inspection.
21.
a.State FOUR actions the Engineer Officer of the Watch would take on discovering a small
oil fire in the engine room bilge (6)
1. State FOUR good watchkeeping practices that can help prevent such fires

mentioned in Q(a) from occurring (4)
22.
Describe the routine inspection of the portable fire extinguishers found in the machinery
spaces (10)
21.
a.Explain the importance of regular fire drills (5)
b.Describe how a drill relating to a fire in a purifier room may be organised (5)
22.
Describe the actions to be taken to operate a bottled C02 fixed fire-fighting system, from the
decision being taken that C02 must be used, to the C02 being released into the compartment.
23.
Name the appropriate regulations and describe the safety practices relating to EACH of the
following: (2.5 x4)
1. Grinding wheels;
2. Rotating machinery;
3. Safety clothing and footwear;
4. Prevention of skin reactions
24.
1. Explain the importance of regular fire drills .(5)
2. Describe how a drill relating to a fire in a purifier room may be organised.(5)
25.
List Ten actions to be taken by the Engineer Officer of the Watch to ensure the safe passage
of the vessel through an area of heavy weather.(10)
26.
a.State FOUR features which assist in the sta1iing of lifeboat engines in cold climatic
conditions.(5)
27.
Briefly describe TWO devices that control the rate of fall of a lifeboat when launched from
standard davits.(5)
28.

Outline a safe procedure for final daily watch-keeping checks of an engine room which is
designated UMS. (10)
29.
Describe EIGHT actions to be taken by the relieving Engineer Officer of the Watch before
taking charge of the watch.(10)
30.
Describe the immediate action that the Engineer Officer of the watch should
take in the event of the engine room bilge rising faster than can be contained
by the bilge pump. (10)
(b) State the features provided in the engine room pumping systems to deal with
the situation in Ql(a). (6)
31.
With reference to the emergency generator:
a.State the checks required prior to starting the engine.(5)
b.Describe the routine testing (5)
9.0 Materials
1.
Write short notes on the following mechanical properties of a metal (10)
(a) Ductility
(b) Elasticity
(c) Hardness
(d) Strength
(e) Toughness
2.
(a) Explain how the microstructure of steel is formulated, depending on the percentage of
carbon content. What is the significance of 0.8% carbon content (5)

(b) Explain how the tensile strength, hardness and ductility of steel changes with the increase
of carbon content.(5)
3.
(a) State the principal properties of Gray Cast Iron and White Cast Iron (3)
(b) Explain the effects of the presence of silicon and the cooling rate on the final
microstructure of cast iron.(3)
(c) Why and where non-ferrous metals and alloys are used in ship building (4)
4.
Give two desirable and two undesirable properties of the following metals and their use in
marine engineering application.(10)
(a) Brass (b) Cast Iron (c) Mild Steel
5.
(a) Outline three main reuirements of a material used in the construction of a pressure
vessel. (6)
(b) Explain how a welded joint could cause failure of the vessel.(4)
6.
(a) Define the meaning of the term ‘creep’ as applied to metals.(3)
(b) Define how the creep value of an alloy steel is determined.(3)
(c) Explain with reason the significance of creep in machinery component failure and how it
is countered.(4)
7.
Explain how non-destructive tests are used for the following:
(a) Detection of surface cracks(3)
(b) Detection of internal cracks (4)
(c) Measurement of hull plate thickness (3)
8.
Make a list of faults found in welding and describe briefly with the aid of a suitable

diagram. (10)
9.
(a) Briefly explain the hardening and tempering process of Iron (5)
(b) Write brief notes on annealing and normalising of Iron (5)
10.
1. a) Explain the essential difference between cast iron and mild steel. (5)
2. b) Explain with reason, the properties of material required for ship side sea water
overboard valve. (5)
11.
(a) Explain the followings (5 X2)
i)Ultimate tensile stress
ii)Creep
iii)Fatigue
iv)Plasticity
v)Elasticity
12.
What are the non-destructive tests carried out onboard? Explain with examples. (10)
13.
(a)Describe the followings non-destructive tests(3 x2.5)
(i)Dye penetrant
(ii) Ultrasonic
(iii) Magnetic particle inspection.
(b) Give one advantage and one disadvantage of any two of the above non-destructive
tests.(2.5)
14.

Define the followings (4 X 2.5)
(a) Magnetic particle inspection
(b) Fretting
(c)Forging
(d )Case hardening
15.
1. a) Give composition & properties and use of (2 X 3)
i.Stainless steel
ii.Heat resistance steel
1. b) State the required properties & composition of use for propeller. (4)
16.
Explain the meaning of the following terms (2.5 X 4)
(a) Fatigue failure
(b) Yield point
(c) Creep
(d ) 0.1% proof stress.
10.0 Instrumentation and control
1.
(a) Sketch a bi-metallic thermometer and explain the working principle (5)
(b) Sketch a resistance thermometer and explain the working principle (5)
2.
(a) Sketch a thermocouple and describe the working principle.(5)
(b) Sketch a manometer to measure the pressure difference across the M/E air cooler. What
action is required if the reading is high.(5)
3.

(a) Draw and describe a rota meter (5)
(b) Draw and describe a rotor meter (5)
4.
(a) Sketch a bourdon tube pressure gauge and explain how it works (8)
(b) What you understand by 5.2 bar reading on a reefer compressor oil pressure gauge when
suction pressure gauge shows 1.9 bar 2.
5.
(a) Draw a DP cell and show how it is used to send the boiler water level. (7)
(b) State two more application of DP cell.(3)
6.
Define following terminologies used in control system (4 X 2.5)
(a) Closed loop control system
(b) Deviation and off set
(c) Gain
(d) Hunting
7.
(a) Sketch a pneumatic P+I+D controller and label all parts (6)
(b) What is the function of the proportional band width adjustment parts (4)
8.
(a) Note the quality of air to be used in pneumatic controllers and why?(4)
(b) Draw a refrigerating type drier and explain how it works (6)
9.
(a) Draw and describe a pneumatic controller in association with Main engine JCW system
and explain how it controls the temperature with out offset. (8)
(b) Which part of this controller removes offset. (2)
10.

(a) Sketch and describe a pneumatic cascade control system that maintains a steady water
level in the boiler. (7)
1. Explain the function of a boiler water level transmitter (3)
11.
(a) Sketch and explain the function of a pneumatic split range control in association with
Main Engine jacket cooling water system.(8)
(b) Define the terminology ‘Dead Zone’.(2)
12.
(a) Sketch a pneumatic booster relay and explain its use (6)
(b) Define ‘Dead Time’ and state why it should be as less as possible.(4)
13.
(a) Draw and describe a pneumatic ‘fail set’ device. State its function.(6)
(b) What is the difference between ‘fail safe’ and ‘fail set’? Give two examples for each in
marine devices. (4)
14.
(a) State four reasons for incorporating a valve positioner in a pneumatic control system.(4)
(b) Sketch a pneumatic valve positioner and describe how it works. (6)
15.
(a) Sketch a hydraulic governor and explain how it works. (7)
(b) Why a load sensing part is required for engines that drive electrical generator.(3)
16.
(a) Sketch a ship board hydraulic system powered by variable delivery pump and capable of
operating a crane. Explain how it works. (6)
(b) In case the power failure occurs, show with a diagram how the system remains safe with a
high load on the crane. (4)
17.
With reference to control terms, define (4 X 2.5)
(a) Cascade control

(b) Split range control
(c) Show with the aid of sketch, the application of cascade and split range control system.
(d) ON-OFF control.
18.
With reference to differential pressure pneumatic instruments
(a) Describe the operation of such instruments.(4)
(b) Explain how the instruments of such instrument may be adapted to measure each of the
following items
i)Boiler water level (2)
ii)Fluid flow (2)
19.
(a) With the aid of sketch explain how the level of boiler is maintained. (5)
(b) Identify the difference between transmitter and transducer. (5)
20.
Define the followings (5 X2)
(a) Closed loop control
(b) Open loop control
(c) Proportional control
(d) Integral control
(e) Derivative control
21.
Sketch and describe its fail safe arrangement how the temperature of main cooling system is
controlled remotely. (10)
22.
(a) What is proportional action control? (2)
(b) What is the advantages and disadvantages of proportional action control?(4)

(c) Why integral action controls incorporate in proportional action control?(4)
23.
Sketch an auxiliary boiler combustion control system. (10)
24.
Describe followings (2.5 X 4)
(a) Bourdon type pressure gauge
(b) Flow meter
(c) Bi-metal thermometer
(d) Level gauge
25.
(a) What is D.P cell? (5)
(b) Draw a system for controlling water level in the boiler. (5)
26.
(a) Sketch and describe a thermo-electric pyrometer.(5)
(b) State the various materials that can be used in its construction and give the approximately
temperature ranges for which these materials are suitable. (2)
(c) What are the advantages and disadvantages of this instrument? (3)
27.
(a) Describe, with the aid of a sketch, a method of remotely indicating the water level of a
main water-tube boiler (10)
28.
Describe, with the aid of a sketch, a typical single element temperature control for a large
lubricating oil system (10)
29.
Describe with simple sketch, an equipment suitable for measuring: ( 5×2)
1. a) Temperature
2. b) Level

30.
a)State the term ‘close loop” control. (4)
b)State the difference between open loop and closed loop control. (6)
31.
1. a) What is D.P. cell? (4) b) Draw & describe a system, for controlling water level in
the boiler (6)
32.
sketch and describe any two of the following: (2 X 5)
1. a) thermocouple b) DP cell c) tachometer
33.
Explain with a sketch operation of a valve positioner.(10)
34.
With sketch describe a Cascade control system used on Board.(10)
11.0 Refrigeration and Air Conditioning
1.
Reference to marine refrigeration systems:
(a) Sketch a simple direct expansion system for ship’s domestic use.(4)
(b)Explain how the flow of refrigerant through the evaporator is regulated and why (4)
(c) What would be the result of fouling on the water side of the condenser tubes? (4)
2.
With reference to refrigeration systems:
(a) Explain what happens in the condenser and the evaporator. (4)

(b) Explain why the refrigerant temperature changes from one side of the expansion valve to
the other. (3)
(c) explain what is meant by the term ‘super heat setting’ of the thermostatic expansion
valve.(3)
3.
With reference to refrigeration plants, state how:
(a) Very low evaporator temperatures are achieved. (2)
(b) Thermostatic expansion valves in direct expansion plants are adjusted. (2)
(c) Compressors are protected from appreciable ‘carry over’ of liquid refrigerant.(3)
(d ) Air in the system is detected. (2)
(e) over charge of refrigerant is indicated. (2)
4.
State with reasons why the following courses of action might be advisable if the temperature
of the ship’s cold lockers rises steadily although the compressor runs continuously.
(a) Defrost the evaporator (2)
(b) “Top-up” with refrigerant.(3)
(c) Clean both sides of condenser.(2)
(d) overhaul compressor (3)
5.
With reference to refrigeration systems:
(a) State how Freon leakage are detected.(1)
(b) Explain the precautionary measures taken to prevent leakage and why. (3)
(c) What do you understand by the Ozone Depletion Potential and Global Warming

Potential. (3)
(d) R134a is used as a replacement for Freon 12, what are the design considerations to be
taken into account in relation to lubricating oil? (3)
6.
With reference to the lubrication of reciprocating refrigerant compressors:
(a) Explain in detail the reasons for oil carry over. (3)
(b) State how the collection of oil in the evaporator coils is prevented. (2)
(c) Sketch and describe a device which returns oil from the system to the sump.(5)
7.
Considering shipboard air conditioning systems:
(a) describe how the temperature and relative humidity of individual rooms are measured
using a hand held instrument. (4)
(b) What is meant by ‘comfort zone’? (2)
(c ) Explain with reasons why the relative humidity should not be too high or too low. (4)
8.
With reference to accommodation air conditioning plants, explain how:
(a) Humidity is controlled. (3)
(b) Air temperature is controlled. (4)
(c ) Air changes and compensation for air loss is achieved. (3)
9.
Explain the following terms with respect to air conditioning:
(a) (i) wet bulb temperature (ii) dew point temperature (iii) relative humidity (4)
(b) Itemize the preventive maintenance you would expect to be necessary on the automatic
controls of an air conditioning plant with which you are familiar. (6)

10.
Considering air conditioning systems:
(a) Draw a plenum system suitable for centralized air conditioning and label the principle
components. (4)
(b) explain how the quantity of air circulated is determined and maintained in a fresh
condition.(3)
(c ) describe the precautions to be taken to ensure the system is kept free of infection. (3)
11.
Considering the design and operation of air conditioning systems:
(a) Describe, with the aid of simple drawings, how the temperature and humidity of
circulating air is controlled. (3)
(b) Show, using a sketch of a psychometric diagram, the region of control for comfort of
personnel. (2)
(c) Explain why the humidity should not be too high or too low. (3)
(d) Suggest how individual room temperatures may be adjusted and what effect it would have
on humidity. (2)
12.
With reference to the conditioning of circulating air:
(a ) Identify four conditions which require to be controlled indicating why control is
necessary. (4)
(b ) Differentiate the terms ‘absolute humidity’ and ‘relatie humidity’. (3)
(c ) Explain how relative humidity can be determined using a sling hygrometer and
psychoetric chart. (3)
13.

With reference to the handling and treatment of circulating air:
(a) Compare the centralised plenum system with the distributed chilled/heated water system
for air conditioning. (4)
(b)How is the spread of fire and smoke controlled where such systems are employed? (3)
(c )What maintenance is required to control noise levels and heat loss/gain in the system
ducting? (3)
14.
With reference to the refrigerated containers:
(a) What is the rational for refrigerated containers in preference to refrigerated bulk cargo?
(3)
(b) How the condition of refrigerated containers/bank is monitored and controlled? (3)
(c ) sketch how the containers are connected to the bank. (4)
15.
(a)State desirable properties of a refrigerant with reasons for the same.(5)
(b)What is short cycling? State a few causes and their remedy for the same.(5)
16.
(a) What are the safety devices fitted in a reefer system? A well designed system
should have an expansion valve that causes the refrigerant to leave the evaporator
with 5 to 7 degree of superheat, should there be an accumulator before he compressor… give
explanation in favour of your answer. (4)
(b) State the causes and remedy of the following symptoms
(i) frosted or sweating suction line (2)
(ii) Warm liquid line ( 2)
(iii) Frosted liquid line (2)

17.
State the causes and remedy of the following symptoms
(a) i. Low discharge pressure (1)
1. High / low discharge temperature (2)
iii. Low oil pressure (2)
1. State the causes and remedy of the following symptoms
2. Oil leaves crankcase (2)
3. Oil does not return to crank case (2)
iii. Oil sight glass shows presence of oil foaming (1)
18.
State the causes and remedy of the following symptoms
(a)i. Crankcase and cylinder temperature relatively warm with low suction pressure (2)
1. Crankcase and cylinder temperature relatively cold/ sweating/frosting (2)
iii. Compressor noisy (1)
(b) State the causes and remedy of the following symptoms
(a) Sight flow indicator shows bubbles in refrigerant (1)
(b) reefer compartment temperature too high (2)
(c) Reefer compartment temperature too low (2)
19.
Describe the principle of operation of a thermostatic expansion valve with
simple diagram. What is the function of an equalizing line. (10)
20.
State the effect of moisture in a reefer system, what are the symptoms and for the same?
What is pump down, how you would figure out that there is air in the system? (10)
21.
Sketch and describe the followings

(a) Compressor crankshaft gland seal.(4)
(b) Pressure switch.(3)
(c) Regulator.(3)
22.
(a) What is relative humidity? (2)
(b) What is dry bulb temperature? (2)
(c) What is wet bulb temperature? (2)
(d) What is legionella bacteria? Where it is found and why it is harmful for human body?(4)
23.
With reference to refrigeration system
(a) State the types of compressor in common use. (3)
(b)Explain with reason, why the refrigerant return is connected with compressor sump? (7)
24.
With reference to refrigeration system, state the effect of (4 X 2.5)
(a) High cooling the liquid refrigerant.
(b) Super heating the suction vapor.
(c)Very low evaporation temperature.
(d)Gradual loss of refrigerant.
25.
Describe the purpose of followings in Freon Refrigeration system (4 X 2.5)
(a) Compressor
(b) Expansion valve
(c) Condenser
(d) Evaporator
26.

(a) Explain the working principle of refrigeration system.(5)
(b) Explain the working principle thermostatic expansion valve.(3)
(c) Explain how does the oil separator works? (2)
27.
a.Describe the operation of a domestic refrigeration plant, refere ncing the refrigerant
condition at the main components.(5)
b.State how liquid is prevented from returning to the compressor.(5)
28.
1. Sketch a simple refrigeration system showing the FOUR major components.(5)
2. State the condition of the refrigerant between EACH component in the sketch of Q(a).
(5)
29.
With reference to a refrigeration system:
(a)Describe how air is removed from the system (5)
(b)Describe how and where refrigerant gas is added to the system (5)
12.0 Regulations
1.
(a) Name the International convention that regulates the prevention of oil pollution at sea.(2)
(b) Describe how oily water from machinery space bilges, when pumped overboard, complies
with the convention mentioned above. (6)
(c) Where are these discharges overboard recorded on board. (2)
2.
(a) Outline the information which should be entered in the Oil Record Book. (4)
(b) Outline the conditions which must be complied with for the discharge of oily water from
machinery space in special areas under Marpol annex I. (4)

(c) State how long the ORB to be kept on board after the last entry. (2)
3.
Define the following abbreviations and briefly explain their relevance in the maritime
industry.
(a) SOLAS (3)
(b) STCW 2010 amendments (3)
(c) MLC 2006 (4)
4.
With reference to the prevention of pollution at sea regulations, explain the purpose of the
following:
(a) Shipboard Oil Pollution Emergency Plan (SOPEP) (4)
(b) Oil Record Book (4)
(c) Shipboard incinerator (2)
5.
(a) What do you mean by BMSO ’83 and ISO 1976? (4)
(b)What is MMD? Who is the legal authority to register Bangladeshi flag ship? (4)
(c) What is Flag of Convenience? (2)
6.
Explain the following terms in more detail:
(a) International Maritime Organization (IMO) (2)
(b) International Safety Management Code (ISM Code) (3)
(c) ISPS Code (3)

(d) IBC Code (2)
7.
Describe the following certificates and their duration of validity: (2.5×4=10)
(a)IOPP Certificate
(b)IAPP Certificate
(c) ISPP Certificate
(d) ISSC
8.
(a) State the meaning of the term “enclosed space” (2)
(b) State THREE areas on board a ship that would be designated as enclosed space.(3)
(c) Outline the procedure for entry into an enclosed space. (6)
9.
(a) State the records of operations which should be entered in the Oil Record Book of all
ships. (6)
(b) State the conditions which must be complied with for the discharge of oily water from
machinery spaces. (4)
10.
Briefly state what do the following certificates stand for and what are their validity periods:
(a) DOC & SMC certificates (4)
(b) Certificate of Registry (3)
(c) Loadline certificate (3)

11.
(a) What is ISM? (2)
(b) What is meant by SEP policy in ISM manual? (3)
(c) What is the validity of ISM certificates and objectives of ISM? (5)
12.
(a) What is ISPS code? Which chapter of SOLAS includes this? (4)
(b) With respect to ISPS code explain: i) ISSC and validity ii) SSO, CSO, PFSO, AIS. (6)
13.
(a) What do you understand by MARPOL 73/78? (2)
(b) State MARPOL regulation regarding prevention of pollution by sewage. (2)
(c ) State MARPOL regulation for machinery space and cargo pump room regarding
prevention of pollution by oil.(6)
14.
(a) What is classification society? (2)
(b) Define the following.
1. i) Annual survey. (2)
ii)Docking survey.(3)
iii) Special survey.(3)
15.
Define a duty engineer officer’s responsibilities with regard to avoidance of pollution of
1. a) Enclosed & inshore water with oil. (4)
2. b) Port atmosphere with smoke. (3)

(c) Explain how (ii) can be avoided when raising steam from cold in an auxiliary
boiler? (3)
16.
(a) State Marpol Annex-VI. Mention when it came into force?(2)
(b)State ECAs, when they came into force? (4)
(c) Mention the compliance of BDN and sample. (4)
17.
According to MARPOL Annex-I define:
(a) Initial survey (2)
(b) Intermediate survey (3)
(c)Periodic survey (3)
18.
(a) What is oil record book? What are the entries in Oil record book? (5)
(b) Describe MARPOL regulation regarding to garbage disposal. (5)
19.
(a) What is IMO 2020? When it came into force? (4)
(b) What is the present maximum sulphur limits for fuel in ECAs & outside ECAs? (4)
(c)What is SIP? (2)
20.
(a) Explain the procedure to change over of Main engine from high sulphur to ECA
compliant fuel during entering ECAs. (6)

(b) Explain why sometimes MDO cooler is used in main engine fuel oil system? (4)
21.
Explain the followings term
(a) EEZ
(b) EEDI
(c) EEOI
(d) IAPP
(e) SOPEP
(f) UNCLOS
22.
(a) State the operations which should be entered in oil record book of all ship.(5)
(b) State the condition which must be complied with for the discharge of accumulated oil in
machinery space. (5)
23.
(a) What is the MLC 2006? What are the two basic aim of MLC 2006? (2)
(b) What are the subjects of the “Titles” of MLC 2006? (4)
(c) What is meant by the concept of “No more favorable” treatment in MLC 2006.(4)
24.
(a) Why ships are classed? What is the process of classification? (5)
(b) Write short notes on “SEEMP, EEDI, EEOI” (3)
(c) State the MARPOL Regulations regarding prevention of pollution by Garbage from ships.
(2)
25.
Define Duty Engineer responsibilities with regard to avoidance of pollution of

(a) Shore water with oil. (3)
(b) Port atmosphere with smoke. (3)
(c) Explain how smoke can be avoided when using steam from cold in an auxiliary Boiler. (4)
26.
(a) List the area addressed by MLC 2006. (4)
(b) List the area addressed by SOLAS’74 convention.(3)
(c) Write short notes on “Flag state Control” & “Port State Control” (3)
27.
(a) How many annexes are there in MARPOL and what are they? (4)
(b) What is classification society? (6)
28.
(a) Define the following (2.5 X 4)
(i) Annual survey
(ii) Docking Survey
(iii)Special survey
(iv)HSSC
29.
List the certificate to be carried by cargo certificate.(10)
30.
With reference to the ISM Code state
(a) The objective of ISM Code (2)
(b) The functional requirement of safety management system (3)
(c) State safety and environmental protection policy of any shipping company under ISM
Code. (5)
31.

Define followings
(a) Non conformity
(b) Port state control
(c ) SOPEP
(d) SSAS
32.
(a) State MARPOL regulation for machinery space and cargo pump room regarding
prevention.(3)
(b) Draw a line diagram of an oily water separator labeling the principles items and showing
direction of flow. (3)
(c) Describe how does it operate? (4)
33.
(a) What is ISM? Explain its objective.(2)
(b) Define the following (2 X 5)
1. i) Designated person ashore
2. ii) Condition of class
iii) Document of compliance
1. iv) Safety management certificate (SMC) .
2. v) Non conformity Report
34.
1. a) State the condition to be complied with it in order that bilge water may be
discharged overboard while the vessel is in a special area. (5)
2. b) Describe with sketch an engine room bilge system that complies with current
legislation.(5)
35.
Define followings (2.5 X 4)
1. a) SOLAS
2. b) STCW 2010
3. c) ISM Code
4. d) MLC 2006

36.
Write down the requirements of training, familiarization and awareness creation among the
seafarer regarding lifesaving appliances as per SOLAS. (10)
37.
(a) What are the objective of Annex-VI of MARPOL 73/78. (4)
(b) Write the name of all emission control areas. (6)
39.
What is the objective of Ballast water management Convention? Write the present ballast
water management regulation to control the pollution.(10)
40.
(a)State the regulations that make each ship responsible for the prevention of pollution at sea
and in port.(2)
(b) Name the equipment that must be used in machinery spaces to comply with Annex 1 of
the regulations stated in Q(a). (2)
(c) Describe the principle of operation of the equipment named in Q(b) (6)
41.
(a)State FOUR conditions to be complied with in order that bilge water may be discharged
overboard while the vessel is in a special area. (4)
(b) Describe an engine room bilge system that complies with current legislation(6)
42.
State, with reasons, FOUR principle requirements for maintaining records on board ship.(10)
43.
Define EACH of the following abbreviations, briefly explaining their relevance in the
maritime industry: (2.5 X 4)
a.SOLAS;
b.STCW’95;

c.ISM Code.
d.MLC 2006
44.
a.State the operations which should be entered in the Oil Record Book of ALL ships.(6)
b.State the conditions which must be complied with for the discharge of accumulated
machinery space (4).
45.
a.Sketch an Aerobic Sewage Treatment Plant.(5)
1. State the conditions which must be complied with for the discharge of sewage
overboard.(5)
46.
With reference to “ISM Code” write short notes on (2.5 X4)
a.Role of company office
b.Advantage of drills and exercises
c.Documented procedures
d.Management Review
47.
Write short note on; (2 X 5 )
a.PORT STATE
b.FLAG STATE
Mohammud Hanif Dewan
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DOS
purifier and system principles

The basic operating principle of the purifier
An efficient combustion in marine engines requires good quality fuel oil. The heavy oil used in engines is
not of the purest form. In order to clean this dirty fuel, oil is sent through a series of purifying equipment’s
before it reaches the engine. Separators / purifiers, clarifiers are two such equipment’s that are used for
purifying and filtering the fuel oil to separate solid particles and / or water.
The easiest of ways of cleaning of fuel is through the method of gravity separation. Gravity is made use of
in this method which separates fuel from impurities and water that are heavier than the fuel which floats at
the top and is collected through an outlet that is made at the top of the container. The impurities and water
can be finally removed by draining of the tank at last.
Centrifuging is the process that is used for faster and most efficient cleaning of fuel. There are separators
that work on the principle of centrifuging.
However, they are divided on the basis of what they separate from the fuel. Separators that remove water /
solids from the fuel are called purifiers whereas those that remove solid impurities are called clarifiers.
Centrifugal force:

F = Centrifugal force, r = Radius , n = RPS

Centrifuging is a process that amplifies the effect of gravity and makes the process of purification faster
and more efficient.

Centrifuges work by rapidly spinning a bowl containing the liquid, thus producing the required centrifugal
force to produce separation.

The principle of operation of the centrifuge is simple. When a bowl containing impure fuel is rotated,
centrifugal forces will throw any item with density greater than the fuel oil density (solids and water) to the
periphery of the bowl while fuel that has the lowest density remains at the center.
Centrifugal separators used for the separation of two liquids of different densities (fuel and water) are
known as purifiers and those used for separating solid impurities are known as clarifiers. Purifiers will also
remove some solids and clarifiers will also remove small quantities of water.
Basic construction of the purifier
Purifier
When a centrifuge is set up as a purifier, a second outlet pipe is used for discharging water as shown.

In the fuel oil purifier, the untreated fuel contains a mixture of oil, solids and water, which the centrifuge
separates into three layers. While in operation, a quantity of oil remains in the bowl to form a complete
seal around the underside of the top disc and, because of the density difference, confines the oil within the
outside diameter of the top disc. It is necessary to prime the bowl each time that it is run; otherwise all the
oil will pass over the water outlet side to waste. The water outlet is at greater radius than that of the fuel.

Within the water outlet there is a gravity disc (shown in green), which controls the radial position of the
fuel water interface.

A set of gravity discs is supplied with each machine and the optimum size to be fitted depends on the
density of the untreated oil. When the fuel centrifuge is operating, particulate matter will accumulate on
the walls of the bowl. If the centrifuge is set as a clarifier, the particulate matter will be a combination of
water and solid material. If it is set as a purifier, the free water is continuously discharged. Therefore, the
particulate matter will consist of solid material. In older machines it is necessary to stop the centrifuge to
manually clean the bowl and disc stack, however, the majority of machines today can discharge the bowl
contents while the centrifuge is running.
Construction

1. Feed valve 2. Clean oil out 3. Liquid 4. Housing 5. Bowl
6. Spring 7. Operating water distributor 8. Check valve 9. Bearing housing
10. Drive belt 11. Electric motor 12. Gearbox 13. Foundation
Basic components of the centrifuge are as follows:

Exterior framework:
The exterior frame work is normally made up of caste iron which supports the internal bowl and disk parts
and carries water line, feed line and outlet line connections.
Bowl and disk:

There are bowls inside the frame, which can be a solid assembly operating continuously and have space
enough to retain the separated sludge. There can also be an arrangement in which the upper and lower parts
are separate for discharging the accumulated sludge during operation. These parts are normally made up of
high tension stainless steel.
Disks improve the purifying efficiency.

The Vertical shaft is used to transform the electrical motor output into rotational motion for rotating the
bowl in high speed through spur gear and horizontal shaft or belt. The material used for vertical shaft
construction is an alloy of steel.
Horizontal shaft or belt drive:
The electrical motor drives the horizontal shaft through clutch pads and is used for transmitting the
rotational motion to bowl assembly. A special belt having elastic character is used in some models in place
of horizontal shaft, thus removing the use of the gear assembly. The horizontal shaft material is a special
alloy of steel.
Spiral gear:
A spiral gear is placed between the horizontal and vertical shafts for the transfer of rotational motion.
These gears are manufactured by special aluminum bronze material.
Clutch or friction pads:
An electric motor will get overloaded if it is connected directly to the bowl assembly for the rotation of the
same as the complete assembly is very heavier. To avoid this, clutch or friction pads and drum assembly
are installed on the horizontal shaft. Normally the number of pads varies from 2 to 4 depending upon the
frequency supply to the motor.

As the motor starts, the pads inside the drum moves out gradually due to centrifugal force and cause
friction in the internal wall of the drum resulting in rotation of the shaft and the bowl gradually without
overloading and damaging the motor and gears.
Attached Gear pump:
A general construction of centrifuge consists of a horizontal shaft driven attached supply or discharge gear
pump. In some system an external supply pump may be installed in place of the attached pump
Sludge discharge mechanism

Fig. shows diagrammatically the method of sealing and sludge ejection for a self-cleaning purifier.
Bowl sections A, B and C, are all keyed to the central drive spindle, B and C, and are secured so that they
cannot move vertically whereas A is free.
The purifier is first brought up to operating speed and water is then supplied to space D through supply
port G. Due to centrifugal force the water pressure in space D moves A vertically to form a seal at the bowl
periphery. Water and then oil would next be supplied to the purifier in the usual way.
When the purifier requires to be cleared of sludge the oil supply is shut off and water supply is changed
over from G to F supply port. The hydraulic pressure created in space E is sufficient to open the spring-
loaded valves and the water from space D will-together with water from space E-be discharged and A will
fall, the bowl seal will now be broken and the sludge ejection will take place. After de slugging is
completed the water supply will change from F to G. The spring load v/v will close & start pressuring the
space D to shut the bowl for the next cycle.
Sequence of discharge sludge

When sludge discharge cycle initiates
1. V1 valve operates and oil inlet by pass the purifier
2. V4 opens for few second and supplies water to the bowl

3. V3 closes, Bowl closing water stops
4. V2 opens, Bowl opening water open
5. Purifier desludge
 Why purifier needs following data concerning temperature, quantity of flow and density
Temperature
HFO viscosity decrease with increasing temperature, so the separation process accelerates as the resistance
to flow (viscosity) is decreased. It means due to less resistance to flow, water and solid particles easily
separates.
Density
In a purifier separation takes place due to density differences. Internal diameter of the gravity disk depends
on fuel density and selection of correct gravity disk is very important. If the wrong dam ring (gravity disk)
is selected water may carry out with clean oil or oil can be seen at the water out let.
Flow rate

Purifier flow rate should be correctly matched with engine consumption and it should be at the optimum
throughput rate as possible but to be just above total fuel consumption.
Difference between purifying and clarifying
When two liquids of different densities are separated using a centrifuge, the equipment is labeled as a
purifier, but when the same centrifuge is used to separate solid impurities from the fuel, it is called a
clarifier.
A clarifier works as a backup system if one feels that purifier has not completely removed dissolved solid
impurities from the fuel.
Purifiers have a Gravity disc / dam ring that works to create a line of separation between fuel and water.
However, in clarifiers, instead of a gravity disc, a sealing ring is used that prevents water and dissolved
impurities to remain inside the purifier bowl.

Purifier
• The discs have holes
• Separates water & heavy solid impurities
• Two outlets on top, each for water & oil
• Gravity disc on top of disc stack.
• Require sealing water while starting.
Clarifier
• The discs have no holes.
• Separates only solid particles.
• There is only one outlet on top.
• No gravity disk ( a disk is used to completely seal the water outlet)
• Sealing water is not required.
Separation as a means of removing impurities from a fuelcan be undertaken bymeansof
gravityin a settlingtankor by means of centrifuging the fuel. Both methods workon the
sameprinciplesthat bysubjecting thefuelto aconstant force, the denser components of the
fuel i.ewater and dirt will be separated from the lightercomponents i.e. thefuelitself.

Gravityacting on thefuel as it passesslowly through thetank will separate the denser
components from the fuelwhere they will accumulate at the bottom of the tank.
Thecontaminantscan then be remove byseparation ofsludge from the tank.
2
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Principle of separation

If an oily water mix is placed into a tank then separationof the two parts will begin
with the lighter element risingto the top. The rate the separation occurs is governed
byseveral factors including the in and the force of gravity
acting upon it.
mixesplaced into a settling tankthere islittle thatcan be done about the gravity but the
in gravities can be increased by heating. Thisbecause water
density changes at a much reduced ratewhen compared to oil. ! wide shallow tank
will increase the rate over a tall thin tank
"

Principles of Separation
#hen a volume of light oil is placed into atank contain a weir and a $uantity of
waterthe %uids will tend to arrange themselves asshown above. The height of the
water in theweir rises to a point governed by the volume&and thereby relative height'
and of the light oil.
(nowing this it is possible to form arudimentary system.
)

Principle of separation
!s a oil*water mix is fed into the tank separationbegins with heavy particulates falling
to the baseof the tank along with water which +oins the otherwaterexcess over%owing
the heavyphase weir.,opefully clear oil passes over the light phaseweir. The problem

arisesthat to ensure theiris nt time to allow for full &separation of theoily mix the
%ow would have to be very smallrelative to thesi-e of the tank.

Centrifuging
Centrifuging is the process by which theeffects ofgravity can be amplified by the use
of centrifugalforce to the that the separation processbecomes rapid and
continuous.Centrifuges work byrapidly spinning a bowl containing the li!uid,
thusproducing the re!uired centrifugal force to produceseparation.
The principle of operation of the centrifuge is simple."hen a bowl containing impure
fuel is rotated,centrifugal forces will throw any item with densitygreater than the fuel
oil density #solids and freewater$ to the periphery of the bowl.
/

Centrifuging
Centrifugal separators used for the separation of twoli!uids of different densities #fuel
and water$ areknown as purifiers and those used for separatingsolid impurities are
known as clarifiers. %urifiers willalso remove some solids and clarifiers will
alsoremove small !uantities of water.
0

Principle of seperation in centrifugecontaining angled plate stack
1

moving between two plates has avelocity greatest at mid point andminimum
approaching the plates.a particle entering into the plates willtend to be pushed
upwards by the %uid%ow. !llthe time centrifugalforce tendsto retard the hori-ontal
component ofthe movement causing the partical toapproach the underside of the top
disc.!s it approaches the %uid %ow velocityreduces.
"
*
3
*

4 5oham
mud ,anif 6ewan7 8enior 9ngg.:ecturer7 International 5aritime !cademy7;angladesh
The centrifugal force eventuallyovercomes the force acting on the particledue to
%uid movement and the particlestarts to move towards the outer rim. Thecentrifugal
force acting on a particle isproportional to its mass therefore a smallparticle will tend
to move further underthe in%uence of %uid %ow. Indeed aparticle small enough will
be carriedthrough the plates and out with thedischarge. In this way it can be seen
thatreducing the %ow rate to a willtend to increase the $uality of the output.
"
*

3
*
3
Typesof Centrifuge&
There are normally two types based on theapplication&'$ Clarifier ()$ %urifier
1)
Clarifier :

"hen a centrifugal is arranged to remove only impuritiesand smallamount of water, it is
called as clarifier. Sinceit isused mainlyforthat fluid where mostlysolidimpurities are to be
removed, gravitydiscisnot used inclarifier* instead asealing ring isused to keep theimpurities
intactunlessdesludged
.
The particle is pushed upwards with the oil streamtowards the centre while the
centrifugal force directs itto the periphery. The residual force on denser

particles#impurities$ will drive them towards the periphery, whilethe less dense
particles #oil$ will be directed towardsthe centre of the bowl and raise to the
outletconnection.

2) Purifier:
"hen a centrifuge is arranged for separating two li!uidsof different densities, for e.g.
water from oil, it is knownas a purifier. The main component of purifier is correctsi+e
gravity disc or dam ring which is responsible tocreate interface between the oil and
water.
The basic operations of clarifier and purifier are:
-t contains stack of disk numbering up to and areseparated from each other by
very small gap. 0 seriesof holes are aligned in each disk near the outside edgewhich
permits the entry of dirty oil.

< 6ue to in gravity and centrifugal force7the heavier impure li$uid &water'
and particles movesoutside and lighter clean oil %ows inwards and
getseparated.< The collected sludge and impurity can be dischargedcontinuously or
at a time intervals7 depending upon theconstruction7 automation and system
incorporated.

#hen a centrifuge is set up as a asecond outlet pipe is used for
dischargingwater as shown. In the fuel oil theuntreated fuel contains
a mixture of oil7 solidsand water7 which the centrifuge separates intothree
layers. #hile in operation7 a $uantity ofoil remains in the bowl to form a complete
sealaround the underside of the top disc and7because of the density
theoil within the outside diameter of the top disc.

0s marine fuel oil normally contains a small!uantity of water, it isnecessary to prime
thebowl each time that it is run, otherwise all the oilwill pass over the water outlet
side to waste. Thewater outlet is at greater radius than that of thefuel. "ithin the water
outlet there is a gravitydisc, which controls the radial position of the fuelwater
interface

! set of gravity discs is supplied with eachmachine and the optimum si-e to be
on the density of the untreated oil.#hen the fuel centrifuge is
operating7particulate matter will accumulate on thewalls of the bowl. If the centrifuge
is set as the particulate matter will be acombination of water and solid
material.
If it is set as a the free water iscontinuously discharged7 therefore7
theparticulate matter will consist of solidmaterial. In older machines it is necessary
tostop the centrifuge to manually clean the bowland disc stack7 however7 the

ma+ority ofmachines today can discharge the bowlcontents while the centrifuge is
running.
23

>peration
The factors are of i!portance understanding the
function of the
-ncreasing the sg of the oil will tend to push theinterface outlet and cause overflow
from the heavyphase outlet untillthe e!uilibrium isrestored. Shouldthe interface be moved sofar
astobreach the damoilwill be issued from the heavy phase outlet and analarm will sound.The
idealposition forthe interface isto lie overthe distribution holes
1educing the sg of the oil willtend to bring theinterface towards the this reduces the
force ofseparation on the oil and reducesthe efficiency ofthe unit possiblyleading to
conExplain how lubricating oil can be tested onboard.
Answer:
L.O can be tested on board by using Maker’s supplied test kit , which can give the result
whether it is safe for further use or not.
For L.O test , sample oil must drawn out from correct point , such as from test cock or from
pump’s discharge pressure gauge connection. It should not be drawn out from , filter out let
and purifier out let .
Sample oil must be taken with standard plastic tube with seal for both on board test and Lab.
analysis.
Acidity Test
– Release a drop of sample oil onto the blotter paper. Then wait about 5 min. allow to spread
itself.
– Add a drop of indicator solution ( Potassium Hydroxide ) onto the spread area of sample
oil. Then wait about 5 min
– Acidity can be determined by color change of sample oil.
– Bluish Green means: – No acidity in sample oil , it is alkaline stage.
– Yellowish Orange means: – Neutral stage , but no longer satisfactory.
– Reddish Color means: – Acidity in sample oil , not fit for further use.
Another test is extracting the acid from sample oil , known as Ph. Test.
– Mix unknown amount of distilled water to sample oil and shake well.
– Then mix with known strength of indicator solution
– Compare with a series of color standard each representing their Ph value .
– Determine Ph value of sample oil quite accuracy.
Fuel Oil Contamination Test ( Viscosity Test )

Fuel oil contamination with L.O may cause by dribbling fuel valve and leaking fuel pump
due to excess wear of its components. When L.O is contaminated with fuel
– L.O color change to dark brown
– Flash point become low
– Viscosity decrease
If fuel oil contamination is occurred , viscosity of L.O to be tested for determination ,
whether fit or unfit for further use.
– The viscosity test can be done 3 tube rolling ball viscometer
– One tube is filled with used sample oil . ( Let say its viscosity grade is SAE 40 when fresh )
– Fill lower and higher viscosity fresh oil into another two tube each and individually ( Let
say SAE 30 & SAE 50 oil )
– Then placed all 3 tube in hot water contained plastic bucket to allow same temperature for a
moment.
– Mount all 3 tube in tilted board and inverted. Internal hollow ball in each tube will rise to
surface.
– If the time taken by ball in sample oil tube is between the time taken by remaining two ball
in their tubes , it means that , the viscosity of sample oil is fit for further use.
– If not , contaminated L.O must be changed.
Water Dilution test
Water may dilute in L.O from…
– Condensation from vapour in the crankcase
– Leakage from Cylinder cooling system ( i.e , JK seal from liner )
– Leakage from steam heating of sump tank.
– Sea water cooler tube..
Water dilution can be check with a Crackling test.
Take sample oil with test tube and heated up while shaking .
If there is no crackling sound , oil is dry.
If there is a slight crackling sound, the oil having trace of water.
If there is heavier crackling and frothing , the oil is heavily diluted with water.
Insoluble Content test
It is very simple test use with blotter paper.
Release each single drop of sample oil and similar fresh oil with known insoluble content .
Wait for complete spread of both oil drops.
Compare the two oil spread condition and determine the content result of test oil.
For straight mineral oil , test result should below 1 ~ 1.5 % of upper limit.
For detergent/dispersant oil below 5 % of upper limit.
(b) How will you rectify in the case of lubricating oil which has been contaminated with
a certain amount of sea water.
Answer:
Lubricating Oil can be contaminated with sea water due to leakage from air cooler tubes and
L.O cooler tubes. It is mostly happen while engine is stopped. Contamination of sea water

can be detected by abnormal rise of sump oil level abnormal water discharge from L.O
purifier and colour change of L.O .
If certain amount of S.W contamination with L.O is detected , batch purification method is
recommended . For the successful purification , the following process should be done.
– Transfer the whole quantity of dirty L.O from sump tank to a storage/renovating tank .
– In this tank , L.O to be heated up to 60 ‘C by provided heating arrangement and allow to
settle at least 24 hour. While settling , water and sludge from L.O to be drained out
frequently.
– At this time , open up M.E crankcase , both wet and dry sump tanks , properly ventilated ,
thoroughly wipe out and cleaned , make inspection and closed back . All L.O piping to be
drained out.
– If condition of L.O in renovating tank is found satisfactorily free from water and sludge in
drainage , start to purify with L.O separator , renovating tank to renovating tank circulation
process.
– To achieve optimum purification effects
– Use correct size of gravity disc
– Minimum feed rate
– Heated up inlet oil to 77 ~ 82 ‘C by purifier heater
– Water washing by using warm water.
– Frequently de-sludge the purifier
– During the process , possible sources for Sea water ingression to be rectified and pressure
test to be done , to
make sure no further sea water contamination.
– L.O acidity , viscosity and water content test to be done frequently and keep batch
purification process until test results are satisfactory.
– Then release L.O from renovating tank to sump tank via purifier outlet for normal engine
operation.
– Even though the test results are found satisfactory , Oil sample to be sent for laboratory
analysis for further recommendations.
BOILER WATER TESTS
(By Kamal Hossain, Chief Engineer)
Q. (a) Explain why regular testing of water in auxiliary boiler is advisable
(b) How to take correct sample
(c) Discuss what factors are necessary when measured value differ appreciably from
desired value in each test.
(d) Give reasons for the situation when alkalinity is found to have fallen unaccountably.
Answer:
(a) For the well boiler operation, boiler water should be tested regularly and accurately.
Then correct chemical treatment should be followed based on the test results for the
following reasons.
– To keep the boiler water in alkaline condition
– To precipitate all scale forming , both dissolved and suspended salts in the boiler water , in
the forms of removable and non-adherent sludge.

– To remove dissolved oxygen , carbon dioxide and other gases
– To produces substances which will be well below the limits for carry over , foaming and
priming..
– To keep their decomposition products not to be harmful to the whole boiler system
– To prevent metal loss due to corrosion
– To prevent scale formation in the system
– To prevent contamination by sea water and by oil
(b) Since highest concentrations are at the water surface , sample should be taken at this
point can represent more conditions . Therefore sample drawing line is located in the steam
drum , just above the water tubes. In order to get proper results , it should be as far as
possible from the chemical feed line. Correct sample must be taken…
– From salinometer cock
– With salinometer gauge
– Allow to flush about 5 min before taking
– Cool down to 25’C before test to prevent flashing which concentrate the sample
– All test apparatus should be cleaned with sample water
– Sample should be tested as soon as possible after drawing
(c) The boiler water should be tested and actions to be taken as follows.
 Excess Phosphate test: Measure content of phosphate salts in the boiler water which
can prevent scale, form non-adherent sludge and give alkalinity. Control limit is 20 ~
40 ppm . If less than 20 ppm dose NaSO4 chemical ( adjunct B ) as per instruction. If
excess 40 ppm , take blow down action.
 Phenopthalein and Total Alkalinity Test: Measure content of NaOH , control
correct pH value and require alkalinity , to remove hardness salts and precipitate scale
forming permanent salts .
– Control limit is 100 ~ 150 ppm. Double for Total Alkalinity test.
If the result is less than 100 ppm , dose the highly concentrate of alkaline
chemical NaOH ( Called G.C )
– If the result is excess , action to blow down , because it may cause caustic corrosion
and embattlement.
 Chloride test: Measure content of NaCL & MgCL to prevent HCL formation in
boiler water. Control limit is 240 ppm . Test result should less than limit . If excess,
blow down action to be taken.
 Condensate pH value test: Measure to power of hydrogen value in condensate to
prevent corrosion. Control limit is 8.3 ~ 8.6.
If the result is less than 8.3, dose SLCC-A corrosion inhibitor chemical increase by 25
%. If more than 8.6 , reduce by 25 %.
(d) When alkalinity is found to have fallen unaccountably in boiler water , this may be caused
by
 Due to boiler water forming acidity by contamination of sea water or any chemical
reaction in boiler water system
 Due to incorrect strength of reagent used
 Due to direct water losing from boiler, resulting all constituent level reduction.

SUMMARY OF STEERING GEAR REGULATIONS &
REQUIREMENTS
SOLAS REGULATION & REQUIREMENTS FOR STEERING GEAR
1. Steering gear compartment must be separated from machinery spaces and readily
assessable.
2. Every ship shall be provided with main steering gear and auxiliary steering gear.
3. The failure of one of them must not render the another one operation.
4. Relief valves shall be fitted to any part of the hydraulic system. Setting shall not
exceed designed pressure, i.e , 1.25 times of working pressure.
5. Main steering gear and rudder stock shall be:

o Capable to put rudder hard over from 35 deg. one side to 35 deg. another side
not more than 28 second while running with full sea speed and full loaded
draught.
o They should be done at maximum astern speed as also.
6. The auxiliary steering gear shall be:
 Adequate strength and capable of steering the ship at navigational speed and could be
brought to action in an emergency.
 Capable to put rudder from 15 deg. one side to 15 deg. another side not more than 60
second with the ship full loaded condition with speed not less than 7 knot.
7. Rudder angle indicator shall be independent from steering gear control system.
8. Means of quick communication to be provided between Wheel house , E.R &
Steering gear room.
9. System oil low level alarm , audible and visible to be provided in Wheel house , E.R
& steering room.
10. Fluid used must be approved type and non freezing.
11. With stock diameter 230 mm and above, an alternative power supply , capable to
provide within 15 second, automatically, must be provided. Its capacity shall be at
least 30 minutes for the ship 10000 grt and above. 10 minutes for other smallers.
12. Electrical wiring system for steering gear shall be sized to accept 100 % load.
STEERING GEAR SURVEY
Steering gear system is subjected to annual survey , intermediate survey and special survey
under machinery items by Classification Society. The following parts are to be surveyed not
exceeding 2 years interval.
1. Fastening of steering gear , quadrants , tillers and rudder brake

2. Any leakage of hydraulic system
3. The motors with starters , control gears and electrical
4. Insulation resistance test to motors and wiring system
5. Function test including emergency operation.
6. Alarm test of safety arrangements , such as
 Oil level alarm
 Control voltage failure alarm
 Over load alarm
 Phase failure alarm
UMS SYSTEM FAILURE
It is complete failure of the UMS, bridge control and data logging system has failed and
the main engine is needed to run on manual control and monitoring.
(a) State with reasons six main items of data, which require to be monitored and
recorded manually.
(b) Explain how a watch keeping system should be arranged to provide for effective
monitoring and control of the main engine.
(c) Explain how the staff will be organized to maneuver the engine safely. State the
machinery plants at which attentions are required during maneuvering.
Answer:
(a) When M.E to be put on manual control and monitoring, the following six main items
of data to be monitored and recorded manually.
1. Cooling water system.
It is required to prevent the thermal stress and thermal loading on the engine. Engine may
breakdown in severe
Case.
– Jacket water temperature and pressure
– Piston cooling temperature and pressure ( If water cool )
– Sea water temperature and pressure ( For Coolers & condenser ) …. to be checked &
recorded.
2. Lubricating oil system
It is required to prevent thermal stress, occurrence of hot spot, local welding between
engaging aspirate and seizure case for severe condition. It is also reducing the wear and tear
in engine component .
– Lub. Oil pressure & temperature for crankshaft bearings & camshaft bearings
– Cylinder Lubrication
– T.C Lubrication……… to be checked and recorded.
3. F.O system
It is required to obtain the correct fuel injection viscosity to achieve good combustion process
in the cylinder.

– Fuel oil pressure at circulation system
– Fuel oil temperature at end heater
– Fuel oil viscosity at visco-therm unit
– Condition of fuel oil settling and purification process… to be checked and recorded.
4. Scavenging & Exhausting
It is required to know the engine’s load distribution, combustion condition, exhaust valve
condition, turbocharger efficiency and charge air cooler condition.
– Charge air temperature and pressure
– Air cooler in / out temperature
– Individual unit’s exhaust temperature
– Turbine inlet & outlet temperature………….to be checked and recorded.
5. Level control
It is required to checked and maintained the correct level of
– Boiler water level for safe running with correct steam pressure
– Cooling water expansion tank level
– Fuel oil settling and service tank level
6. Speed and revolution counter
It is required to monitored and recorded running machinery speed and revolution counter, to
determine the engine
performance with respect to exhaust temperature and load condition.
– M.E r.p.m
– Turbocharger r.p.m
(b) Monitoring & Control
To obtain effective monitoring and control of main engine, E.R attend watch keeping to be
provided instead of UMS system. In every watch , one certified Engineer in full charge and at
least one assistant should be performed. Watch keeping should be 3 shifted as follow :
– 00 ~ 04 and 12 ~ 16 watch 2/E + one assistant
– 04 ~ 08 and 16 ~ 20 watch 1/E + one assistant
– 08 ~ 12 and 20 ~ 24 watch C/E + one assistant
Overtime could be assigned for 2 hour each after completion of day time watch keeping.
Electrician , Fitter and remaining crew ( if any ) to be assigned day work ( Normally 0700 ~
1600 )
In the watch hour, watch keepers must keep the close watch to monitor and maintain all
temperature and pressure of the running machinery. All data to be collected and entered to
Chief Engineer’s log book 4 hourly .
(c) Organization to Engine room staff (for safe maneuvering)
When M.E running with manual control and monitoring , there should be full strength of E.R
crew to present in E.R for safe manoeuvring. In addition to present watch keeper, stand-by
Engineer and day work crew must present in E.R when engine is given stand-by notice. In the
manoeuvring period, the followings to be assigned.
– As a Chief Engineer, he is a responsible person in full charge in E.R
– Duty Engineer should take engine movement control.

– Standby Engineer should keep close watch in engine room’s machinery and maintain all
temperature and pressure within normal limit.
– Electrician should be standby for main switch board and help to record engine’s movement.
– Assistant watch keeper should take care of air compressor and fuel centrifuging.
– Fitter and day work crew should attend in M.E individual platform, check engine
movement and stand-by for emergency case.
The following machinery plants are required to pay attention during maneuvering.
– M.E warming All temperature and pressure to be maintained within normal limit while
manoeuvering period.
– Generator plant : Require two generator in parallel operation to sufficient manoeuvring
loads. If not satisfactory standby generator must be running idle for emergency.
Emergency generator room to be clearly opened and keep ready.
– Air compressor plant Attention to pay air compressors and air reservoirs . Alert to change
air bottle if air pressure drop to minimum starting level.
– Fuel Centrifuging Normally, Diesel oil is used for manoeuvring. Therefore check D.O
service tank level and topping up as necessary.
– Boiler plant E.G boiler may not sufficient to produce required steam pressure. Therefore
aux. oil fired boiler have to put in service. Correct firing procedure and its safety measures to
be watched.
– Steering gear Keep watch its proper function . Alert to change emergency operation in case.
COC ORAL EXAM PREPARATION (PART – 18):
ELECTRICAL MISCELLANEOUS
Servicing a motor effected/washed by seawater:
1. Cut out power supply by circuit breaker & taking out fuse. Mark & disconnect supply
wire. Took Megger reading & recorded.
2. Take out the motor, open up & dismantle. (Make sure marking on both cover & body)
3. Clean and wash with warm fresh water.( About 180′ F)
4. Cover by canvas, dry with positive ventilation & 500 watt lamp
5. Clean with Electro cleaner.
6. Baking by 500 Watt lamp for few hours.

7. Take Megger reading. (test stable or constant reading) Apply insulation varnish to the
winding while warm.
8. Baking & taking the Megger.
9. Reassemble & put back into service.
10. When test run check sound, ampere & temperature.
Safety device on alternator:
1. Heater
2. Cooling fan.
3. Reverse power trip.
4. Preferential trip.
5. Over current trip.
6. Under voltage trip.
Windlass safety device:
1. Slipping clutch.( Fitted between hydraulic motor and gear)
2. Over load trip.
Winch safety device.
1. Over load trip.
2. Centrifugal brake.
3. Magnetic brake.
4. Limit switch for runner, topping & slowing.
5. Hydraulic oil high temperature alarm & cut out.
6. Hydraulic oil over head tank low level alarm.
Megger:
A Megger is an ohmmeter to measure insulation resistance in million of ohms. (Pole to pole,
pole to earth). Good insulation has high resistance; poor insulation, relatively low
resistance. The actual resistance values can be higher or lower, depending upon such factors
as the temperature or moisture content of the insulation (resistance decreases in temperature
or moisture).
Purpose of Megger Test:
1. To verify insulation resistance.
2. To detect any insulation fault.
Correct Procedure to Check Megger:
Switch off main switchboard by means of circuit breaker & taking out fuse, put label of MEN
AT WORK, disconnect the connection from stator, teat with Megger Meter. Measure during
hot condition resistance for accurate reading.

The Megger insulation tester is essentially a high-range resistance meter (ohmmeter) with a
built-in direct-current generator. This meter is of special construction with both current and
voltage coils, enabling true ohms to be read directly, independent of the actual voltage
applied.
This method is non-destructive; that is, it does not cause deterioration of the insulation.
(Image Credit: electrical-engineering-portal.com)
Fig: Megger test instrument hook-up to measure insulation resistance.
The generator can be hand-cranked or line-operated to develop a high DC
voltage which causes a small current through and over surfaces of the
insulation being tested (Fig). This current (usually at an applied voltage of 500
volts or more) is measured by the ohmmeter, which has an indicating scale.
Safety device on switch board:
1. Circuit breakers
2. Over current relay (OCR) for protection from high current
3. Reverse power trip
4. Preferential trip
5. Under voltage trip
6. Fuse
7. Earth lamp
8. Synchroscope, synchronising lamp.
9. Meter (ampere, frequency, volt, watt)
10. Dead front panel safety device provided on the Main switch board individual panels
wherein you cannot open the panel until the power of that panel is switched off.
Shore supply connections
 Where arrangements are made for the supply of electricity from a source on shore or
other location a suitable connection box has to be installed in a position in the ship
suitable for the convenient reception of flexible cables, it should contain a circuit
breaker or isolating switch, fuses, and terminals of adequate size to receive the cable
ends.
 For three phase shore supplies with earthed neutral terminals are to be provided for
connecting hull to shore earth
 An indicator for shore side connection energised is to be provided.
 A means for checking polarity or phase rotation is to be provided

 At the connection box a notice indicating ships requirements with respect to supply as
well as connection procedure.
 Alternative arrangements may be submitted for consideration.
How will you know the shore power supply is correct or not?
 Phase sequence indicator.(inside shore connection box, turn clock wise direction)
 Operate E/R vent fan & check airflow direction.
When excitation loss:
 Tapping with hammer to field coil core of excitation motor.
 Energise with battery.
Preferential trip:
If a generator overload condition develops, its preference overload trip will operate to
energise the timing relay. The timing relay then operates to disconnect non-essential services
in a definite order and at definite time intervals.
 None essential (without effecting the ship operation.) 5 sec:
 Essential (running the ship properly) 5 sec:
 Top polarity (propulsion, navigation) 15 sec:
Static electricity:
 Electricity produced on dissimilar materials through physical contact & separation
 Out going material negative, remaining material positive.
Spontaneous combustion:
The ignition of material brought about by a heat producing exothermic chemical actin within
the material itself, without exposure to an external source of ignition. (Wet oily rags, wet saw
dust)
Armature reaction.
– When a D.C generator or a motor is operating with load, sparking between the carbon
brushes and the commutator results due to Armature Reaction. Armature reaction takes place
when the armature current flows in the armature.
– When current flows in armature, the armature core is magnetising by this current.
Magnetising effect of the armature current can be divided into two effects: –
 Cross magnetising or distorting effect.
 Demagnetising or weakening effect.
To compensate the Armature reaction, modern Electrical Machines are provided with

 Interpoles
 Carbon brush rocker.
 Neutralising Winding.
A.C motor starters:
A motor starter is an apparatus used for controlling the starting of an electric motor.
1. Direct on line starter.(without current limiting element)
2. Resistor or rheostatic starters.(with current limiting device)
3. Star delta starter.
4. Auto Transformer starter.(reduced voltage starting 55%, 60%, 70%, full voltage
running
5. Rotor resistance starter.(starting slip ring induction motor)
Dash pot
Mechanical device to produce a time delay action. Operation of switch gears, arc lamps,
motor starters, Electro magnetic bake, etc. Time delay is adjusted by oil viscosity used.
Earth detecting lamps
 The earth fault detector consists of three incandescent lamps which are connected in
star. These three lamps are supplied from the secondaries of three single phase step
down transformers. The primaries of three transformers are connected in star. The star
point of the primaries is connected the frame of the ship. The primaries of these
transformers are fed from the red phase, yellow phase and blue phase of the ship
supply.
 Giving visual signals and buzzer will sound when there is an Earth fault in the system
on board.
 Three incandescent lamps which are connected in star. These three lamps are supplied
from the secondaries of three single-phase step down transformers.
 The primaries of these three transformers are connected in star. The star point of the
primaries is connected the Frame of the ship. The primaries of these transformers are
fed from the Red phase, Yellow Phase and Blue Phase of the ship supply main.
 No Earth Fault in the system, Lamps will glow with equal brightness.
 When earth fault occurs one of the phases, the lamp on that phase will become dark
and other two lamps will burn with extra brightness.
 Earth fault can be traced by switching off the branch circuit breaker one by one. When
the branch circuit with the fault is switched off, the earth lamp will return to its
normal glow.
Emergency power supply:
1. Emergency lights.
2. Navigation lights.
3. International communication equipment.
4. Day light signalling lamp.
5. Ship’s whistle.

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