cat60y

• For a fire or explosion to take place, there must be heat, oxygen and fuel

• 1. 1. In the crankcase of the main engine, the oil particles are churned into small 
     2. If a hot spot comes in contact with these small particles, forms mist, 
     3. These particles move towards the colder region inside the crankcase space and when in c…

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5 types of heat treatment are 

1) Normalising 

– Steel is heated slow to temperature which internal structure takes place 

-Sooked at this temperature

-Cooled slowly in air 

2) Annealing 

– Similar to normalizing 

-Different cooling rate are required for different material 

-After heating, soaking, steel is cooled…[Read more]

Corrosion is a primary concern on ships when it comes to burning heavy fuel oil in the marine engines. It can be further described as:

• Hot Corrosion: It occurs due to the presence of Vanadium (Va) and Sodium (Na) in the fuel oil and affects exhaust passage of the engine
• Cold corrosion: It occurs due to the presence of sulphur in fuel oil a…

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Nondestructive testing (NDT) is the process of inspecting, testing, or evaluating materials without destroying the serviceability of the part

Visual inspection inspect for high splatter, undercut,bad stop start point, surface crack.

• Surface inspection 

• Magnetic particle
• Liquid penetrant 

• Internal i…

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Firstly before on the important of keeping scavenge space clean, safety and risk acessment as the main priority. 

1. Prior to entering enclose space, risk assessment to be carry out by competent officer
2. Potential hazards to be identified. Such as toxic gas.
3. The space have to check for oxygen content using gas detector. Oxygen should read…

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1) when taking over duties 

– As C/E, upon joining vessel check ROB of all grades of Lo for any difference 

– Check the daily consumption 

-Check for sufficient Lo for voyage 

– Check for Lo analysis 

2) Ordering of Lubricant 

– Take ROB of grade 

-Identify economical port 

-Check sounding and how much to be taken <…[Read more]

If office ask for max liftable bunker, 85% of available tank 

• voyage – distance, speed, weather, anchorage, port stay

• vessel – Dead weight tonnage, avoid overloading, draft restriction for cargo calculation

• any interal transfer done for ship stability

• as per company policy, 85% volume, no more than 90%<…

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Explain Sampling Procedure of lube oil?

• Draw samples from a connection that comes directly out of the main oil supply line to the engine.
• Always sample for the same point.
• Sample only when the oil is up to its operating temperature with the engine running.
• Depending upon the draw off point, sufficient amount of oil should be d…

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Oil is selected to improve the engine operation and reduce the wear down rate and hence the maintenance cost of the machine.

Alkalinity

• When fuel burns, the fumes carry sulphuric acid which can cause acidic corrosion. Four stroke engines, the main lube oil is responsible for piston and liner lubrication; alkalinity of lube oil is impor…

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1. Spade or Balanced Rudder
1) A spade rudder is basically a rudder plate that is fixed to the rudder stock only at the top of the rudder.

 In other words, the rudder stock (or the axis of the rudder) doesn’t run down along the span of the rudder. 

The position of the rudder stock along the chord of the rudder (width meaning, from the for…[Read more]

1) it is to ensure a solid frictional drip between propeller and shaft, the use of pilgrim nut facilitates the transmission of engine torque without using key.

2) Pilgrim nut is basically a hydraulic jack with threads, screwed into slot provided on tail shaft. Propeller is forced onto tapered tail shaft region by using a steel ring, which…[Read more]

The keyway on the shaft taper is a source of defects leading to fatigue cracks developing because of the sudden change on the surface shape leading to stress concentrations around the keyway because of its sharp corners. If the key and keyway are eliminated about 75% of this problem is solved. Hence the need for keyless propeller…[Read more]

Valve Hysteresis 

It is an undesireable characteristic which affect valve positioning. 

Effect is the actuator pressure does not produce the same valve opening

Causes 

1) non linearity in actuator force due to varing effective diaphragm area 

2) non linearity in valve opening force due to varying opening rate 

3) non…[Read more]

1)Akin to the ‘Black Box’ on airplanes, a Voyage Data Recorder is an equipment fitted onboard ships that record the various data on a ship which can be used for reconstruction of the voyage details and vital information during an accident investigation.

Information is stored in a secure and retrievable form, relating to the position, move…[Read more]

1. Loss of Oil from Crankcase

– Operational leakage

– Foaming

– Suction pressure drops rapidly from evaporator

– Compressor running on high capacity (unloading setting)

Action

– Use defoaming agent during prolong shut down

– Shut stop valve in liquid supply line to expansion valve

– Suction and discharge valves to shut…[Read more]

To fully prevent oil leakage. #3s added as spare ring

In case of leakage, #3s seal ring is put into operation by close the line valve for #3, #3s will activate

In case of all seal failure,

1. Adjust LO pressure of stern tube to equal or higher then sea water pressure by changing the gravity tank position. If seawater leaking in
2. If…

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Sacrificial Anodic Protection

1. Sacrificial anodes work on the principle of electrolysis,
2. an anode and a metallic strip are dipped in electrolytic solution, 
3. Anode electron will dissolve and deposit over the metallic strip and make it a cathode.
4. Seawater acts as an electrolyte and transfers the electrons from the anode to the steel…

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 Reasons taking too long to fill up. 

• Unloader leaking
• Bottle drain valve or relief valve leaking
• Air consumption increase due to some valve kept open, someone using air continuously, air leakage on pipe/ flange.

factors affecting volumetric efficiency,

• bumping clearance increase
• suction & discharge valves sticky, leaky

…

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Possible causes:

1. 1. 1. 1. Flame eye dirty 
         2. Pilot burner. ( DO tank empty, do pump not working, nozzle choked, igniter electrode>  no voltage, position wrong, fouled or gap too much)
         3. Air/ fuel ratio incorrect
         4. Air fuel ratio adjusting linkage incorrect
         5. ACC failure

Main burner 

1. Valve shut 
2. Filter cho…

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Turn down ratio indicates the flexibility of burner to cope with different loads without losing efficiency.

TRD = fuel consumption at max load/ fuel consumption at minimum load.

Pressure jet burner TDR 3:1

Rotary cup TDR 15:1

Steam blast TDR 20:1

Ultrasonic  TDR 15:1 

• Simple pressure jet burner

Atomization of f…[Read more]