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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]

1. Combustion control system correct the proportion the quantities of air and fuel being burnt. 
2. Ensure complete combustion
3. The system measure the flow rates of fuel oil and air in order to correctly regulate their proportions.
4. Two control elements are used, ‘steam flow’ and ‘steam pressure’. 
5. The steam pressure signal is fed to a c…

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Difference between a safety valve and a relief valve

• Relief valve:

The higher the pressure, the more the valve disc lifts off its seat. Relieving capacity increases with over-pressurization increase.  

• Safety valve:

Designed to stay completely closed until the popping pressure is reached. At popping point the valve lifts sharply a…[Read more]

Fitting of new tie rod 

1. The lower nut of tie rod is screwed on 
2. Clean the seating surface of intermediate ring and upper nut 
3. Screw ring screw on tie rod and lift till the lower tie rod rest against the bearing shield 
4. Tighten the upper tie rod nut with tommy bar until seated firmly, then remove ring screw

Tightening Seq…[Read more]

The Chief Officer must always carry out a full and final inspection of all cargo holds before presenting them for shipper’s final approval and acceptance, to ensure that all cleaning work has been carried out as per his instructions and to his satisfaction, and that he is satisfied that the cargo holds are in a suitable condition for the carriage…[Read more]

Preparations before Dry-docking

1. Prepare Repair Specifications in advance for budgeting and inviting quotations
2. Pipe Lines
3. Structural steel renewal, for which plate thickness gauging may be required.
4. Overhauling of Mooring Equipment.
5. Special servicing requirements
6. Overhauling and testing of Cargo Gear ( cargo pumps if the vessel…

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Preparation and checks before drydock for receiving shore power:
A chief engineer to ensure the following checks are made to ensure safe operation.

ship’s electrical engineer will prepare the ship’s power receiving terminal box and should do following things:

• Ensure the receiving box is not obstructed with any object, pipes or spares. It…

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The ship’s main engine comprises of several bearings, which assist the moving parts such as crankshaft, connecting rod, crosshead etc. The bearings supports the journal pin to avoid metal to metal contact, to reduce the rotational friction, and to transfer the load through lubricants.

Main engine bearings are opened up for inspection or r…[Read more]

The purpose  is to inspect ship hull of damage, any organic build up in lieu to dry dock inspection

In water survey can find weld cracks prior to painting

In water survey to save time during dry dock

Requirement for inwater survey

• 1. Calm weather 
  2. Warm seawater
  3. At anchorage
  4. Enough draft, watier surface
  5. Ship at e…

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Scope of tail shaft survey

Propeller to be withdrawn for inspection

• • 1. Visual inspection
    2. Crack detection test 
    3. Check threads for damage 
    4. Check tapered cone for roughness
    5. Scoring on liner
    6. Check bearing face and white metal
    7. Measurement of tailshaft external diameter to measure wear down.
    8. Stern tube analysis r…

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https://www.youtube.com/watch?v=x7KjSLYmvJM&t=25s

1) Oct 2016 imo decide the sulphur limit (sox) under marpol VI of 0.5%m/m enter force on jan2020 

2) Ships operating within emission control area shall not exceed 0.1%m/m on or after jan2015

3) Under the marpol amendments 

• Ship shall not use non-compliant fuel oil by jan 2020, and s…

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https://www.youtube.com/watch?v=vvVzBJ952E4“>Heres an interesting video from Mothership about Flag state control
What is the first impression of the ship upon going up the gangway. Are the security measures in place? This will be the observation for ISPS.

1) Master’s office; Certificates and documents

Inspection starts at master’s office to con…[Read more]

https://www.youtube.com/watch?v=9g89KEbYd6I
Contents of Ballast Water Management Plan

1. Reduce the harmful effects on the marine environment spread by invasive aquatic microorganisms transferred from one area to another through ballasting operations.
2. (IMO) adopted a convention in order to control and manage ships ballast and sediments on on…

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