Admin

Daily checks 

• Check the lubrication
• Check the noise level by operating the crane without load
• Check the heat generation
• Check all the limits and trips are working properly
• Check the contact areas of electrical equipment
• Check the brake operation
• Check condition of clamp in the hook

2)PMS 

• Overhauling of motor

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Zener Diode
Definition: A heavily doped semiconductor diode which is designed to operate in reverse direction is known as the Zener diode.

Diodes generally are known as a device that allows the flow of current in one direction (forward biased) and offers resistance to the flow of current when used in reverse bias. Zener Diode  on the othe…[Read more]

The Important safety devices fitted on main switch board are:

• Circuit breakers: A circuit breaker is an auto shut down device which activates during an abnormality in the electrical circuit. Especially during overloading or short circuit, the circuit breaker opens the supplied circuit from MSB and thus protects the same. Different circuit b…

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Factors that affect insulation 

1) Moisture

• Leakage current increases

2) Dust, oil, deposits on end of winding and connections

• Cause insulation burn out overtime
• Reduce heat dissipation, dust clog 
• Ventilation duct and restrict free flow of air
• Increase machine temperature and cause thermal degradation on i…

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Ppe 

must be of correct insulating class 

• • 1. electrically insulating safety helmet
    2. insulating rubber gloves

must satisfy international IEC standards, subjected to dielectrical, mechanical resistance and ageing test.to check if easily broken

• • 1. Insulating gloves
    2. Pneumatic glove tester, 

    <…

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1. Air Circuit Breaker (ACB) is used to provide Overcurrent and short-circuit protection. 
2. Air as an arc extinguishing medium.

Air Circuit Breaker Working

1. Air Circuit breakers generally have two pairs of contacts.
2.  The main pair of contacts (1) carries the current at normal load and these contacts are made of copper metal. 

<…

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1) disconnect non essential circuit from main bus bar in case of failure or overload of main supply

2)Example Air con, Ventilation fan Galley equipment 

3)Prevent main circuit breaker trip, prevent blackout, overloading of generator 

4)Preferential trip circuit consist of electromagnetic coil, arrangement to provide delay to disconnect n…[Read more]

• • • The reverse power relay is prevents power from flowing in the reverse direction. 

• • • The relay is used in installations where a generator runs in parallel with another generator

• • • to prevent power from the bus bar or another generator from flowing back to the active generator when…

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• 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]