SOME BASICS Q & A PART- 4

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Candidates should know about starting air explosion and crankcase explosion, causes, remedy and action.

Q: What inspections is carried out on piston ring?

i) Axial clearance .

ii) Butt clearance

iii) Ring thickness

iv) Radial thickness

v) Ring tension

Q: What inspection should carry out with cylinder liners?

i) Check the ridge on top of liner remove by grinding if any

ii) check for crack, oilyness

iii) Check lubricators, condition of retaining Cylinder LO

iv) Check for wear (gauging), ovality

v) Scuffing

vi) Abrasive wear

vii) Corrosion

Q: What is thrust block?

This makes use of the engine bedplate and seatings to distribute the propeller thrust to the ships structure.

Q: What is the function of flywheel?

i) Stores energy while acceleration and releases while deceleration, smooths out fluctuation of engine speed.

ii) Turns the engine for maintenance

iii) Used as pointer of engine position

Q: What are the TBN values for C/C oil of cross head engines and trunk piston engine?

Engine using residual fuel, C/C oil to be alkaline.
For X-head engine 10-15 TBN
For trunk piston engines up to 40 TBN

Q: What is microbial degradation?

It is a infection of C/Case oil by micro organism. They live by consuming hydrocarbons in the base oil together with nitrogen, sulphur and phosphorus from additives. Cooling water etc. leakage are responsible for depleting the above situation

Safety requirements for working shipboard electrical systems:

Electrical shock and the fire can cause loss of life and damage to the equipment, hence in general following should be complied :

  • To be familiar with ship electrical equipment and diagrams.
  • Operate as makers instructions
  • Maintain as per makers instruction
  • Guards, covers, doors etc securely tightened
  • While shutting off the power, inform duty officer or engineer of the watch
  • While maintenance being done, remove fuse etc.
  • Before working with the equipments confirm circuit is dead.
  • Do not leave the live conductors or rotating parts exposed
  • Avoid overloading equipment
  • Use appropriate warning notices

 Q: What are the conditions of electric shock?

Minimum 15 mA AC or DC current is sufficient to cause an electric shock. Circuit may be from the hand to hand or hand to foot. Shock current depends on the applied voltage and body resistance. sadly, If the applied voltage goes up, body resistance goes down, that means shock current is further increased.

Constructional and operational characteristics of the Shipboard AC and DC electrical systems and equipment;

Candidates should be familiar with alternators & motors and their protection, A/C switch Boards.

Q: What are the safeties of the panel boards?

i) Guarded

ii) Insulated barriers

iii) Some of the panel board cannot be opened unless the breaker is off.

iv) Adjacent floor covered by insulated mats.

Q: During your watch you find low insulation resistance alarm, what is your action?

Inform chief engineer officer & electrical engineer officer. Meanwhile take the following actions to find & detect the faulty equipment.

  • Isolate/change the running motor and check megger
  • If not found, check galley, laundry equipments
  • Deck crane electrical motors
  • Fwd/aft electrical equipments

After the faulty equipment is removed from the electrical supply, insulation indicator will restore back to normal.

Q: How do you check insulation resistance?

i) Phase to phase

ii) Phase to earth.

Q: In dry dock while putting shore electrical connection, what will you check?

 i) Check supplied voltage

ii) Frequency

iii) Phase sequence

iv) If shore supply is earthed neutral, then the ships body has to be earthed.

v) Check the capacity of the circuit breaker.

Q: What is the sequence method synchronizing ? If synchroscope & light methods are out of order how do you parallel generator?

Two lights bright and one light goes out, synchronizing method is sequence method.
Same phase of bus bar and incoming generator are connected across a 500 V voltmeter. When voltmeter indicates 0 to max. slowly & when voltmeter shows at zero, breaker to be closed. This is the point where they are in perfect phase sequence.

Basic Working Knowledge of the relevant IMO convention regarding safety of life at sea and protection of the marine environment.

Q: What is IMO ?

Ans: International Maritime Organization, a specialized agency of the United nations, concerned solely with Maritime Affairs, first adopted in 1948.

Q: State about Annex VI, when it came in force?

MARPOL Annex VI is an international agreement under UN for eliminating air pollution by ships. From 19th May 2005, the Sulpher content of the fuel used must be maximum 4.50%, but there are restrictions on other polluting material that may have been introduced into the fuel.
Bunker delivery Note (BDN) to retain three years. Bunker MARPOL Oil samples to be preserved for 1 year. BDN should have: (i) Name and IMO No of receiving Vessel., (ii) Port, (iii) Date of commencement, (iv) Name, address, tel No. of supplier, (v) Product Name, (vi) Quantity, (vii) Density at 15°C (viii) Sulphur content (ix) Declaration that it complies with annex vi.

General Knowledge of principle structural members of a ship and the proper names for the various parts.

This is a self explanatory topics, candidates should remain familiar with above. However, some important examples are given as a reference only:

Sheer Strake: The upper most line of plating in the side shell in known as the Sheer Strake.

Bulwarks:  Ships are fitted with the solid plates at ships side to prevent personnel falling which is called bulwarks.

Water tight bulk head: Water tight bulk head are formed by plates which are attached to the shell, deck and tank top by welding.

Water tight door: A water tight door is fitted to any access/ opening in a watertight bulk head.

Strength Members: Side framing transverse; center girder about position of Keel, longitudinal are fitted at various locations specially between at the bottom Location and tank top to give additional strength.

Free Board: Is the distance from the waterline to the top of the deck plating at the side of the free board deck amidships.

Net Tonnage: It is obtained by deducting from the gross tonnage, the tonnage of spaces which are required for the safe working of the ship.