QUESTION BANK GENERAL ENGINEERING KNOWLEDGE PART-2

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Q Discuss the advantages and disadvantages of adopting the following policies for maintenance of main and auxiliary diesel engines:

a) Planned maintenance.

b) Condition monitoring.

c) Periodic replacement of components.

Q A new vessel exhibits severe aft end vibrations.

a) As a 2/E officer, outline a procedure to investigate & identify the source of vibration.

b) Suggest possible remedies to obviate / reduce aft end vibration.

Q Discuss the cause of vibration & noise in main gearing and describe its possible detrimental effects on machinery & operating personnel?

How would you detect the source(s) of this vibration & how might it be reduced to tolerable limits?

Q a) Explain how analysis of used lubricating oil can be used as a “health-monitoring” tool for diesel engines.

b) Describe how vibration measurement can be used with a main engine turbo-charger:

i. For fault analysis.

ii. For condition monitoring with respect to the maintenance.

iii. As a substitute to opening up machinery for the survey.

Q a) Sketch & describe TWO methods that employ manometric means for measuring tank content.

b) State what corrections are made to the readings obtained by the methods described in (a) in order to gauge the mass contents,

c) Explain how bunkering requirements may be estimated when no records of the main engine fuel consumption are available on board.

Q You had to discharge to shore 200 tonnes of emulsified and contaminated fuel oil. You had attempted to purify this oil but were unsuccessful. Write a report to your head office explaining the above, how the oil became emulsified & contaminated, & what steps have been taken to avert a reoccurrence.

Q With regards to care of lubricating oils on board answer the following:

a) Microbial degradation of the lubricating oil & measures to prevent the same.

b) Method of ensuring correct sampling is done for the purpose of the shore based testing.

c) If shore based testing results show abnormal value of the water content & TBN for crank case lube oil of a slow speed main engine, what will be interpretation & subsequent action?

Q a) Explain how analysis of used lubricating oil can be used as a “health-monitoring” tool for diesel engines.

b) Describe how vibration measurement can be used with the main engine turbo-charger:

i. For fault analysis.

ii. For condition monitoring with respect to the maintenance.

iii. As a substitute to opening up machinery for the survey.

Q State why the temperature of the lubricating oil supplied to an engine needs close control. Sketch & describe an arrangement & explain the principle of operation of instrumentation & control equipment for automatically maintaining the temperature of lubricating oil supplied to an engine at its desired value?

Q Sketch & Describe 2 Methods that employ Man METRIC Means for Measuring Tank Contents State What Corrections are to be made to the Reading Obtained by the Methods Described? Explain how Bunkering Requirement May Be Estimated When no Records of the Main engine Fuel Consumption are available

Q Describe the operation of overhauling, testing and setting a fuel valve for an auxiliary Diesel engine. How the following Diesel engine faults should be rectified:

a) A smoky exhaust

b) One cylinder exhaust gas temperature is abnormally low

c) The engine does not appear to be using any lubricating oil

Q It is important to maintain the quality of lubricating oils in main and auxiliary diesel engines:

a) Discuss critically the methods used to maintain crankcase oils on the various ships in which you have served.

b) Drawing conclusions from (a) state, as second engineer, your preferred methods of maintaining crankcase oil quality.

Q Describe the type of pump that would be installed in a hydraulic system for deck machinery;

a) Explain the possible causes of contamination in a hydraulic system.

b) Describe the likely results of contamination

c) Explain how contamination is monitored.

Q Reverse osmosis is the modern alternative for shipboard production of drinking water.

a) Describe using  the simple diagrams if necessary, the principle of reverse osmosis.

b) i. Sketch a line diagram showing a single pass system for producing fresh water from sea water.

ii. Describe such a system.

Q With reference to multi-tubular heat exchangers explain:

a) How and where impingement attack is likely to occur in the multi-tubular heat exchangers tubes?

b) Why it is desirable that coolant flow rate should not exceed that required to maintain correct fluid temperature?

c) Ample well-shaped water boxes and smooth tube inlets are desirable?

d) Partial obstruction of tube bore is a common cause of tube failures?

Q a) Draw a line sketch of a system used as an alternative to low pressure evaporator for producing water on board ship?

b) Explain its working principle

c) What are its inherent advantages & limitations?

Q a) Sketch and describe a low pressure evaporator utilizing low grade heat to produce the distillate.

b) State, with reasons the prohibitions placed on the use of the evaporator with regard to the location of the vessel.

Q An auxiliary boiler water level control system has a differential pressure transmitter as the detecting element for water level:

a) Sketch and describe such an arrangement.

b) If the transmitter was damaged describe how a replacement unit would be calibrated

Q a) Describe with the aid of a sketch, the main engine ancillary equipment for automatic monitoring and regulation of fuel viscosity.

b) Explain the operation of equipment described in (a)

c) Discuss the multi fuel concept.

Q a) With reference to the adoption of unmanned machinery spaces, describe suitable automatic control and alarm systems to deal with:

i. High bilge level

ii. Fuel oil tank overflow

iii. Bearings overheating

iv. Fire direction.

b) Comment on the method & frequency of testing the equipment & the energy supply source to ensure unfailing continuous operation.

Q With reference to pneumatic differential transmitters:

a) Sketch & describe such a transmitter

b) State the duties that they may perform

Q Sketch, & describe, a valve suitable for reducing air pressure & maintaining the reduced pressure within close limits. Describe the processes through which the air from the starting air receivers should be treated before it is used in a pneumatic control system.

Q a) Explain how and why the performance of reciprocating air compressor tends to “fall off” in service.

b) State how “fall off” is indicated & to what extent permissible before correction.

c) Describe how optimum performance is restored.

d) What is the significance of “clearance volume” for the reciprocating air compressors?

Q a) Explain why it is essential to assure adequate cooling of air compressor cylinders, inter coolers & after coolers.

b) State with reasons the possible consequences of prolonged operation of the compressor if these areas are not adequately cooled.

Q Give reasons why each of the following features is considered desirable in air compressors:

a) Smooth air passages with minimum obstruction at the valves

b) Minimum clearance volume

c) Multi-tubular heat exchangers

d) Generous size of suction filter

Q a) Explain the necessity of  the intercoolers on a multi-stage compressor. What attention is needed to keep them safe and in good working order? Sketch & describe an intercooler suitable for a 2400 kPa compressor & state materials used.

b) What attention is needed before opening up for inspection? What faults are likely to develop in an air compressor & how are they remedied.

Q With reference to reciprocating air compressors explain why:

a) Clearance volume is critical to efficiency

b) Spring-loaded plate valves are invariably used

c) Compression is accomplished in apparently unequal stages

d) Inter cooling is used between the stages

Q Describe the term “volumetric efficiency” as related to air compressor. Describe the effect of the following faults in multi stage reciprocating air compressor:

a) Inter stage cooler starved of cooling water

b) Worn crank shaft bearing

c) Broken or worn scarper ring

Suggest a fail safe arrangement in the event of the inter stage cooler water loss.

Q Briefly Explain, how the performance of a 3 stage air compressor is assessed & what are the method used for ensuring optimum performance, with justification on each such method?

Q a) Sketch a main engine air stating system and describe how it operates.

b) List the safety devices and interlocks incorporated in such a system and state the purpose of each.

Q a) Sketch a reciprocating air compressor incorporating a first stage rotary compressor.

b) Explain the motive behind such an arrangement.

c) State with reasons whether the advantages claimed for this design justify the Added complexity.

Q Describe the construction of a 3 stage air compressor:

a) Give the temperatures and pressures at each stage?

b) Where are the drains?

c) What type of oil is used and why?

d) Why inter cooler are used in multistage compressor?

Q You have been appointed as Second Engineer of an older vessel which is in dry-dock and recently been purchased by your shipping company. Describe in detail about your inspection, to ensure that the equipment on board related to safety equipment (equipment related to fire fighting and life saving) survey are satisfactorily complied with?

Q The pipe work of the sea water circulation system for a passenger ship has to be completely renewed. The company contracted for the work has no previous experience of marine installation. You as the Second engineer have been requested to write the specification for manufacture and installation of the steel pipe.

a) Outline your proposal for manufacture of the pipe.

b) State the necessary requirements for approval

Q A Rating has been seriously injured by a “blow back” from the oil fired auxiliary boiler. As Second engineer, make a full report to Head office explaining the circumstances of the incident and the precautionary measures now taken to reduce the possibility of a similar occurrence in the future, with the necessary reference to the ISM Code.

Q During a loaded sea passage an unusual noise followed by excessive vibrations were experienced in the engine room of your vessel while she was underway. Vessel is fitted with a four bladed propeller directly coupled to a 2 stroke Diesel engine. Engine room is located aft. After preliminary investigation and from the engine parameters, you have come to the conclusion that propeller has sustained damage. Write a letter to your company reporting this incidence and justification for your conclusion suggesting future course of action.

Q You have been appointed as the Second Engineer of an eight years old vessel, recently purchased by your shipping company. Write a report to the engineering superintendent covering the inspection of main propulsion machinery carried out by you, to ensure its trouble free operation.

Q a) The UMS monitoring & control system of your ship has recently started to give false alarms and incorrect data printouts. State, with reasons, possible causes if the false alarms & reading are:

i. Localized to a particular area of engine operation

ii. General to the engine room

b) State, with reasons, the action you, as 2/E, would take to ensure continued safe operation of the vessel if the defects were general to the engine room.

c) Explain the procedure you, as 2/E, would adopt in order to locate & rectify a general fault in the UMS system.

Q Damage has occurred to the main engine exhaust valves & the fuel supplied at a particular port is suspected. The owner’s case/ however, in the ensuing dispute may be weak because the fuel was ordered specifying only type & viscosity.

a) Apart from fuel specification, describe how you, as 2/E, should have assisted the owner’s case when receiving the suspect fuel.

b) Describe a recognized fuel standard that may be used when ordering bunker fuel.

c) Explain how the correct fuel standard selected.

d) Suggest, with reasons, why particular mention should be made of certain elements that might not be included in the fuel standard.

Q You have recently joined a vessel as Second Engineer Officer. For the past several voyages it has been the practice on board to dispense with the use of the exhaust gas boiler and leave it to run dry. As part of an overall economy drive the company has requested you to re-commission the boiler. Write a letter to the Superintendent Engineer stating how the boiler was brought on line the safety valves adjusted.

Q In view of the number of fatalities involving inert gas used for fire fighting purposes, your company is considering alternative methods of protection for the machinery spaces. As Second Engineer, compile a letter to the company expressing your views for the retention or rejection of inert gas systems and stating your opinion on viable alternative systems.

Q The vessel on which you are serving as 2/E develops an oil leak from the stern tube aft oil seal whilst on voyage. Write a letter to the owners of the vessel regarding the incident, describing the temporary emergency measures taken to stop the oil leak in order to allow the vessel to enter Indian territorial waters for cargo discharge & dry docking without contravening MARPOL 1973/78. Also information about the cause of the oil leak & the action to be taken in dry dock to rectify it may be mentioned.

Q It has been found necessary to completely replenish all of the oil in the lubricating system of a large motor ship (or steam turbine ship). Write a detailed report to the Superintendent Engineer justifying this heavy expenditure, the expediencies needed to avert further trouble during the voyage, & suggestions of permanent measures to avoid a recurrence of the initial problem