Auxillary Flashcards
Q1
With reference to MARPOL Annex 6:
(a) State the current special areas identified for diesel engine NOx and SOx emissions (8)
(b) State the current SOx emission limits globally AND for emission control areas. (4)
(c) State the required documenation that must be held onboard to show compliance with NOx regulations (4)
Need to check answers
Under MARPOL Annex VI, the following are the current special areas designated for diesel engine NOx and SOx emissions: 
(a) Special Areas for NOx and SOx Emissions:
1. Baltic Sea Area: Designated as both a SOx Emission Control Area (SECA) and a NOx Emission Control Area (NECA). 
2. North Sea Area: Also designated as both a SECA and a NECA. 
3. North American Area: Encompassing designated coastal areas off the United States and Canada, this area is designated as both a SECA and a NECA. 
4. United States Caribbean Sea Area: Covering areas around Puerto Rico and the United States Virgin Islands, designated as both a SECA and a NECA. 
5. Mediterranean Sea Area: Designated as a SECA, with regulations entering into force on 1 May 2024 and taking effect from 1 May 2025. 
6. Canadian Arctic Waters: Designated as both a SECA and a NECA, with amendments entering into force on 1 March 2026 and taking effect from 1 March 2027.
7. Norwegian Sea: Designated as both a SECA and a NECA, with amendments entering into force on 1 March 2026 and taking effect from 1 March 2027.
(b) Current SOx Emission Limits:
• Global Limit: As of 1 January 2020, the maximum allowable sulphur content in fuel oil used on board ships operating outside Emission Control Areas is 0.50% m/m (mass by mass). 
• Emission Control Areas (ECAs): Within designated SECAs, the sulphur content of fuel oil must not exceed 0.10% m/m.
(c) Required Documentation for NOx Compliance:
To demonstrate compliance with NOx regulations under MARPOL Annex VI, ships are required to carry the following documentation on board:
1. International Air Pollution Prevention (IAPP) Certificate: This certificate confirms that the ship complies with applicable air pollution prevention requirements, including those for NOx emissions.
2. Engine International Air Pollution Prevention (EIAPP) Certificate: Issued for each applicable marine diesel engine, this certificate certifies that the engine meets the NOx emission standards set out in MARPOL Annex VI.
3. Technical File: Accompanying each EIAPP Certificate, the Technical File provides detailed information about the engine’s components, settings, and operating parameters, as well as the results of emission testing.
4. Record Book of Engine Parameters: This log records any adjustments or modifications to the engine that could affect its NOx emissions, ensuring ongoing compliance with emission standards.
Maintaining these documents on board is essential for demonstrating compliance during inspections and audits.
Q2
(a) Explain TWO factors that have an influence on the separating process within a centrifugal purifier. (8)
(b) Explain TWO reasons for a purifier not attaining full running speed (8)
a) The course of separation can be influenced by changes in viscosity/density/temperature and throughput (process liquid supply rate).
(b) The purifier may fail to attain full running speed if:
Brake is on
Friction surfaces of clutch shoes are oily
(a) Explain TWO factors that have an influence on the separating process within a centrifugal purifier. (8)
(b) Explain TWO reasons for a purifier not attaining full running speed (8)
Q2a explain TWO factors that have an influence on the separating process (8)
-Input temperature of the oil to be purified
-The density of the oil which is to be purified
Density of oil
The density of the oil directly affects the separator’s ability to distinguish between oil and impurities.
• Centrifugal separation principle: Separation depends on the difference in specific gravity (density) between the oil and contaminants. If the density difference is too small, separation becomes less efficient because the centrifugal force has less effect in pulling the heavier components outward.
• Incorrect bowl setting: Separators are often set up with specific gravity discs or gravity rings. If the density of the oil is not correctly accounted for, the wrong disc may be used, leading to carryover of water or sludge into the clean oil line.
• Fuel type variation: Different fuels (e.g., MGO vs. HFO) have different densities, so the separator must be adjusted accordingly to maintain purification efficiency and avoid cross-contamination or mechanical issues.
-Temperature of the oil.
• Viscosity reduction: As temperature increases, the viscosity of the oil decreases, making it thinner and allowing suspended impurities (such as water and solids) to separate more easily. Lower viscosity helps in forming distinct layers during centrifugal separation.
• Separation efficiency: Warmer oil promotes better separation because the lighter and heavier phases (oil, water, sludge) can migrate more efficiently under centrifugal force.
• Recommended practice: Manufacturers often specify an optimal temperature range (e.g., 85–98°C for fuel oil) to achieve maximum separation efficiency. If the oil is too cold, the separation is poor; if it’s overheated, it can cause thermal degradation or affect the integrity of certain components.
B) Give TWO reasons for a purifier not attaining full running speed (8)
-Fouled, dirty, heavy sludge deposits on the purifier bowl
-Driving motor, bearings worn, under-performance
- a) State two factors that have an influence on the separating process.
-Flowrate of oil provided by the feed-pump.
b) Give two reasons for a purifier not attaining full running speed.
-Brake has been left on by mistake, preventing purifier from attaining full speed.
-Driving pad or belt being worn or dirty with oil which will cause slippage and poor grip of the bowl
driving wheel.
Sure! Here’s a solid explanation of two reasons why a purifier may not attain full running speed, tailored for a marine engineer IAMI written exam answer:
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- Drive System Fault or Slippage
• Description: Most purifiers are driven by either friction belts, direct coupling, or clutch mechanisms. If there is belt slippage, worn belts, or a faulty clutch, the bowl will not reach its designed operating speed.
• Impact: Insufficient speed reduces the centrifugal force, which is crucial for effective separation. This leads to poor purification and potential contamination of clean oil systems.
• Example: A loose or oil-contaminated V-belt may slip during startup, preventing the bowl from accelerating to full speed.
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- Excessive Bearing Friction or Mechanical Resistance
• Description: If the purifier’s internal components—especially the bowl bearings, spindle, or journal bearings—are worn, poorly lubricated, or damaged, they create excessive friction or resistance during rotation.
• Impact: This mechanical resistance can prevent the motor from reaching full RPM, possibly triggering motor overload or protective shutdowns. It also increases the risk of overheating or vibration damage.
• Example: A purifier with insufficient lubrication to the top bearing may struggle to accelerate, leading to slow or uneven bowl rotation.
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Let me know if you’d like a quick summary version for notes or a model answer in formal exam style.
Q3
Describe the purpose of EACH of the following publications issued by the Maritime and Coastguard Agency (MCA):
(i) Merchant Shipping Notices (MSNs). (4)
(ii) Marine Guidance Notes (MGNs). (4)
(iii) Marine Information Notes (MINs). (4)
(b) State how it can be determined that such MCA publications have been superseded or cancelled. (4)
a) (i) MSNs – Convey mandatory information that must be complied with under UK legislation. These MSNs relate to Statutory Instruments and contain the technical detail of such regulations.
(ii) MGNs – Gives significant advice and guidance leading to the importance of the safety of shipping and life at sea and to prevent or minimize pollution from shipping.
(iii) MINs – Marine Information Notes are intended for a more limited audience e.g. training establishments or equipment manufacturers, or contain information that will only be of use for a short period, such as timetables for MCA examinations.
(b) It can be determined that such MCA publications have been superseded or canceled from particulars updated/modified notices on the same subject. Additionally, it can also be determined by checking the historic record of current/active notices, through the MCA website.
Q3
Describe the purpose of EACH of the following publications issued by the Maritime and Coastguard Agency (MCA):
(i) Merchant Shipping Notices (MSNs). (4)
(ii) Marine Guidance Notes (MGNs). (4)
(iii) Marine Information Notes (MINs). (4)
(b) State how it can be determined that such MCA publications have been superseded or cancelled. (4)
- a) Describe the purpose of each of the following publications issued by the Maritime and
Coastguard Agency (MCA):
i) Merchant Shipping Notices (MSNs): are used to convey mandatory information that must be
complied with under UK legislation. These MSNs relate to Statutory Instruments and contain the
technical detail of such regulations.
GREGOR CONNOR 30
ii) Marine Guidance Notes (MGNs): give significant advice and guidance relating to the
improvement of the safety of shipping and of life at sea, and to prevent or minimise pollution from
shipping.
iii) Marine Information Notes (MINs): are intended for a more limited audience e.g. training
establishments or equipment manufacturers or contain information which will only be of use for a
short period of time, such as timetables for MCA examinations.
b) State how it can be determined that such MCA publications have been superseded or cancelled.
By the release of an M notice via email or other means. Marine Information Notes will have a
cancellation date on them (which will typically be no more than twelve months after publication).
Q4
(a) With reference to a control system, list FOUR examples of a measured variable. (4)
(b) Explain the meaning of the term two step control, giving one example of its use. (6)
(c) Explain the meaning of the term proportional control, giving one example of its use. (6)
(a) FOUR examples of measured variables in a control system are:
Temperature (Jacket water temperature, LO temperature).
Pressure (Fuel oil pressure, LO pressure).
Level (Boiler water level, FO service tank level)
Rotational speed (TC RPM, Engine RPM)
(b)This is the simplest form of control. Here only two control positions are allowed; on or off. In the case of a valve, it opens or closes by the signal from the controller. Examples for such control system are; water level control for boiler cascade tank, air compressor cut in cut off control, temperature control for fuel oil storage tanks, etc.
(c) A proportional control system is a type of linear feedback control system. The principle aim of proportional control is to control the process as the conditions change. This controller sets the manipulated variable in proportion to the difference between the set point and the measured variable.
In this case when the tank level drops from high the pump kicks in at a variable rate to stabilise the level in the tank. However this method will always result in an offset. This is because the pump just matches the output rate
Q4
(a) With reference to a control system, list FOUR examples of a measured variable. (4)
(b) Explain the meaning of the term two step control, giving one example of its use. (6)
(c) Explain the meaning of the term proportional control, giving one example of its use. (6)
- With reference to a control system, list four examples of a measure variable (8)
• Temperature
• Electrical Voltage
• Flow Rate
• Pressure
b. Outline the basic action of a two-step controller (4)
The two-step controller output signal changes from one value predetermined value to another when the deviation of the
measured variable changes. This is not the same as ON-OFF control especially in digital systems.
C. Outline the basic action of a proportional controller (4)
The proportional control acts to maintain the output variable near constant by adjusting the process (hot cold mix)
proportionate to the deviational value, with the smallest possible offset.
Q5
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:
(a) Galley. (4)
(b) Accommodation space. (4)
(c) Machinery space control room. (4)
(d) Main electrical switchboard. (4)
a) Galley:
Foam, in the event of an oil-based fire.
CO2, in the event of a fire with electrical equipment.
(b) Accommodation spaces:
Water, in the event of a combustible material’s fire.
Dry Powder, in the event of a fire involving electrical equipment.
(c)Machinery space control room
Foam in the event of an oil-based electrical fire.
CO2 in the event of a fire involving electrical equipment.
(d)Main electrical switchboard
CO2 in the event of a fire involving live electrical systems that are critical.
Dry Powder in the event of a fire involving live electrical equipment non-critical.
Q5
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:
(a) Explain TWO factors that have an influence on the separating process within a centrifugal purifier. (8)
(b) Explain TWO reasons for a purifier not attaining full running speed (8
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(a) Two Factors Influencing the Separating Process in a Centrifugal Purifier (8 Marks)
- Relative Density (Specific Gravity) of Fluids
• Explanation: The difference in density between the fuel oil and the contaminants (water and solids) affects how well the purifier can separate them.
• Greater the difference, the more efficient the separation.
• If densities are too close, the separation is poor because the centrifugal force can’t differentiate them effectively.
• Memory Tip: “Big gap, better snap!” (Larger density difference = cleaner split) - Operating Temperature
• Explanation: Higher temperatures reduce the viscosity of fuel oil, making it flow more freely and separate more easily from water and sludge.
• If the oil is too cold, it becomes thicker and harder to separate.
• Standard operating temp is usually around 98°C for HFO.
• Memory Tip: “Warm oil runs clean” (heat helps the separation scene)
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(b) Two Reasons Why a Purifier Might Not Reach Full Speed (8 Marks)
- Faulty or Worn Bearings
• Explanation: Damaged or dry bearings increase friction, preventing the bowl from accelerating to its designed speed.
• This can lead to imbalance, vibration, or even damage to the machine.
• Memory Tip: “Bad bearings, slow spinning” - Drive System Issues (Motor or Belt Slippage)
• Explanation: If the drive motor is weak, misaligned, or if belts are loose or slipping, the bowl won’t reach full RPM.
• Some purifiers use friction or clutch mechanisms that can also fail.
• Memory Tip: “Loose drive, slow dive” (weak motor or slipping belt = low speed)
Q3
Describe the purpose of EACH of the following publications issued by the Maritime and Coastguard Agency (MCA):
(i) Merchant Shipping Notices (MSNs). (4)
(ii) Marine Guidance Notes (MGNs). (4)
(iii) Marine Information Notes (MINs). (4)
(b) State how it can be determined that such MCA publications have been superseded or cancelled. (4)
a) d. Describe the purpose of each of the following publications issued by the MCA
i. Merchant shipping notices MSNs (2)
To provide mandatory information that must be complied with under UK legislation
ii. iii. Maritime guidance notices MGNs (2)
To provide significant information and advice relating to the improvement of safety of shipping and life at sea
Marine information notes MINs (2)
To provide temporal information, relating to MCA examinations and similar articles
State how it can be determined that such MCA publications have been superseded or cancelled (2)
The release of an M notice or PUBLICATION UPDATE via e-mail or other means, previous M notices should be archived
for reference
Q4
(a) With reference to a control system, list FOUR examples of a measured variable. (4)
(b) Explain the meaning of the term two step control, giving one example of its use. (6)
(c) Explain the meaning of the term proportional control, giving one example of its use. (6)
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(a) Four Examples of a Measured Variable (8 Marks)
These are the things that sensors “measure” in a control system:
1. Temperature – Measured with thermocouples or sensors (e.g. engine coolant or exhaust temp).
2. Pressure – Found in systems like fuel, lube oil, air, steam.
3. Flow Rate – Fuel flow, cooling water flow, etc.
4. Electrical Voltage – Used in electrical panels, generators, sensors.
Memory Tip:
“The Pirate Flew Electricity”
(T = Temperature, P = Pressure, F = Flow, E = Electricity)
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(b) Two-Step Controller (4 Marks)
What it does:
• It switches between two states (e.g. HIGH or LOW) based on the value of the measured variable.
• Think of it like a traffic light with just green and red – no in-between.
Example:
• A bilge pump controlled by water level:
• If water level rises above a set point – pump ON
• When it drops – pump OFF
Not the same as simple ON/OFF because it works on preset switching points in digital systems.
Memory Tip:
“Two-step = Two states”
(One value to another based on limits – like flip-switch logic)
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(c) Proportional Controller (4 Marks)
What it does:
• Adjusts the output gradually depending on how far the measured variable is from the setpoint.
• More deviation = more adjustment.
• Less deviation = less adjustment.
Example:
• Mixing hot and cold water:
• If temp is too low, controller opens hot water more
• As temp gets closer to target, it opens less
Memory Tip:
“P = Proportional, Precise”
(Makes small or big changes based on how big the error is)
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