SOME BASICS Q & A PART 2

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Q:  What action you are going to take in the event of a fire or accident?

Ans:    The Abbreviation of Fire:

          F – Find         or                 Find

          I –  Inform                         Isolate

          R – Restrict                        Report

          E – Extinguish                   Extinguish

On watching a fire remove the source of combustion and inform the bridge and Chief Engineer, raise fire alarm, so that others will remain aware of the situation, will muster & come to help. In the meantime try to extinguish the fire with appropriate means.
If there is any accident happened inside engine room, inform bridge, Chief Engineer and raise emergency alarm so that other crew members will muster and come to help/rescue as appropriate. Meanwhile take corrective actions as deemed necessary.

Q: How does emergency alarm ring?

Ans: Continuous ringing of bell. Emergency situation is explained at the muster situation. Pattern of Emergency signal is indicated on Muster list

 Q. Care and management of auxiliary boilers:

Candidates should able to draw automatic combustion system of a boiler.

Q: What was the type of boiler in your last ship? What is the difference between the fire tube and water tube type?

Ans: AALBORG, Composite Boiler.

Fire Tube Type: Due to simple design of the tubes effective heat transfer takes place, but periodical cleaning or maintenance is slightly difficult. Soot blowing is not effective for regular cleaning. Used with low pressure boiler.

Water Tube type: In contrast to fire tube type heat transfer is not so so effective. Gas side cleaning is simple, sometimes fixed water spray design is used for cleaning. Soot blowing is effective when used with medium – high pressure boiler.

Q: What is Ogee ring?

 Ans: Connects the bottom of the furnace to the boiler shell plating.

Q: How is the boiler Gas side is cleaned during operation?

  • By means of steam, soot blowing
  • By injecting soot remover powder to the system.

 Q: What is the blow off pressure of the safety valve?

Ans: Max design pressure of the boiler.

Q: Sketch a gauge glass and explain about blow down procedure.

  • Close steam and the water cock, open drain cock, nothing should come out the cocks are not leaking.
  • Open and close  the steam cock to check cock is clear.
  • Open and close  the water cock to check cock is clear.
  • Close the drain
  • Now open water cock, water should gradually rise up the top of gauge glass.
  • Now open the steam cock, the water should fall to the level of the water in the boiler.

Q: What are the consequence of low water level? What is your immediate action?

Boiler running without water will cause overheating the tubes, tube plates and shell, that will lead the boiler to face thermal stress damage, crack or rupture of the tube, tube plates, shell plates.
Hence, low water level alarm should be activated and boiler firing will shutdown. When the boiler water level found minimum at the water cock level it is safe to put feed water in the boiler. If the level is below this line care has to be exercised not to thermally stress boiler while putting water into boiler.

Q: What are the consequence of high water level? What is your action?

 Ans: This will cause priming of the boiler, loss of heat from the heaters, possibly loss of steam pressure.As far as possible steam heating to be minimized temporarily, carry out partial blow down to normal level. Then introduce normal heating again.

Q: What are the purpose of treating boiler water?

a) Prevent scale formation

b) Prevent corrosion

c) Control of sludge formation & prevent carry over to the system d) Prevent entry of foreign matters in to the boiler

Q: What are the type of chemicals are used to treat low pressure boilers?

Ans:    Lime Ca(OH)2  and soda ash are used Na2CO3 are used to deal with calcium and magnesium compounds in the boiler water.

MgCl2 + Ca(OH)2 —>  Mg(OH)2 + CaCl2 

CaCl2  + Na2CO3  —>  CaCO3 + 2 NaCl

Q: What are the problem if boiler water contaminated with oil?

  • Create layer on the boiler plates, tubes etc and reduces heat transfer and thermal stresses are induced.
  • Initiates corrosion

Care and Management of Steering Systems:

Q: With regard to capacity state the regulations for steering gear?

  • A vessel at her deepest draught and at maximum service speed should be able to move rudder angel from 35° one side and to 30° other side. It should be capable to move 35° one side to 30° other side within 28 seconds.
  • The auxiliary steering gear should be able to move from 15° one side to 15°  other side at half service speed or 7 knots whichever is greater in 60 seconds.

Describe steering gears routine checks before departure & arrival ports.

  • After prolonged use of auto pilot check remote or manual steering on arrival.
  • Check both the steering gear power unit on arrival, run simultaneously on maneuvering channel.

On departure from port within 12 hours:

  • Check main and auxiliary steering gear
  • Remote control system for steering gear
  • Steering position on navigation Bridge
  • Check Emergency power supply
  • check compass rudder angel position
  • Check alarms
  • Auto isolation arrangements

Q: How often the emergency steering drill is carried out on ship? How you used to implement in your last ship?

Ans: Every three months.

Controlling the pumps in both direction by means of manual push buttons from steering gear room locally.

Q: What is the function of by pass valve & relief valves?

Ans: By pass valve are used to open circuit any particular unit.

Relief valves are given to relief over pressure, especially during rough sea undue movements of rudder created extra oil pressure which is relieved by them to avoid any rupture, leakage, damage.

Care and management of pumping systems:

Candidates should aware of various pumps working principle.

Q: Classify pumps.

  • Positive displacement pumps e.g. reciprocating, screw, gear etc.
  • Rotor dynamic e.g. Centrifugal, Propeller etc.

Q: A centrifugal pump not taking suction, what action are you going to take?

  • Check valves open
  • Suction live have crack/leakage
  • Air Ingress to check, primer to check
  • Suction line jointing to check
  • check suction filter clogged
  • Check the wear ring clearance excessive
  • may be the impeller securing arrangement detached.

Q: Why positive displacement pumps require relief valves?

Ans: with the pumping action, pumping rate is same but if the delivery is obstructed the pressure will be built up gradually, which will damage line, casing etc. To protect from over pressure relief valves are required to be fitted.

Q: What type of pump is used for Oily water separator? Is centrifugal pump is suitable for the above?

Ans: Positive displacement pumps for example rotor line screw, reciprocating and gear pumps are used for the above. Centrifugal pumps are not suitable for oily water separator because they produce large quantities of small oil droplets.

Q: How in tubular coolers thermal expansion is allowed?

  • By means of expansion pieces
  • By means of free end arrangements

Q:  What for “bilge injection” v/v is used? What is relevant regulation?

Bilge injection valve is used in case of serious flooding in the machinery space. Diameter of the valve must be 2/3rd of the diameter of main sea inlet, valve spindle should be clear of engine platform.

Care and Management of oily water separator equipment:

Candidate should be aware to draw a commonly used two stage oily water separator and its working principle.

Q: What are the function of oil sensing probe?

Ans: The Capacitance probe in 1st stage senses and causes the solenoid to be energized through control switch. So, control air access to the diaphragm controlled piston valve to drain oil to bilge oil tank.

Q: what is the functions of coalesce filter ?

Ans: Removes fine solids up to certain extent. Small drops of oil coalesces to form larger drops. These rise up to oil collecting space.

Q: How to ensure no accidental discharge overboard will take place from O.W separator?

  • 15 PPM alarm monitor will activate  and discharge pump will stop automatically.
  • Three way valve will trigger on reaching effluent content 15 PPM, will divert the flow to bilge water tank instead of O/B.

Construction, maintenance and operation of fire fighting equipment, fire detection and fire prevention:

Candidate should know the basic principle of operation of portable extinguishers, fixed fire fighting installations and fire detector sensors.

Q: With regard to capacity state the regulations for emergency fire p/p.

  • Capacity should be at least 40% of the fire pumps but not less than 25m3/hour.
  • To supply 2 jets 13 mm dia with a horizontal throw of 40ft.

Q: How does smoke detector works? How do you test it ?

Smoke is sensed by the photo electric call, this signal is transmitted to trigger the alarm.

It can be tested by

  • Smoke
  • Spray can

Q: How does sprinkler system work? Where is it used ?

Sprinkler heads are fitted with quartzoid bulb. Heat expands the liquid and shatters the bulb. Water strikes on the deflector to ensure a cover of floor area of 12m2. On dropping system pressure sprinkler P/P starts automatically.
It is used for accommodation, alleyways of passenger ships and some cargo spaces

Q: What is international shore connection?

It is provided to enable water to be supplied from another ship or from shore to the fire main.
PCD 132 mm, Outer diameter of flange 178 mm, Bore (inner dia of flange) 64 mm.
4 bolts of 16 mm dia and 50 mm length are required.

Q: With regard to CO2 total flooding state the regulations ?

85% of the CO2 gas must be released within two minutes. The quantity of gas carried must be enough to give a free gas volume equal to 40% of the volume of the space except where the horizontal casing area is less than(<) 40% of the general area of the space.
Must give a free gas volume equal to the 35% of the entire space whichever is greater

Q: How the CO2 total flooding system is maintained on ship ?

CO2 room visual check is to be carried out regularly CO2 alarm checked on monthly basis and servicing and others checking of the system is carried out annually by authorized work shop.
Modern marine vessels maintain routine checklists of weekly, monthly, quarterly, 6 monthly and annually

Q: What is fireman outfit?

a) A safety lamp

b) A fireman’s axe

c) A breathing apparatus or  Smoke helmet,  or  a smoke mask.

Q: Before wearing a BA set, what would you check?

  • Pressure normal; 140-210 bar
  • Test alarm whistle working
  • Check mask “seals”, not leaking
  • Alarm comes when the air contents are brought about 80%.

Q:    State the procedure of CO2   flooding

On completion of assessment, permission granted by Master in consulting with chief engineer to carry out flooding:

  • Personnel counted
  • All openings sealed including flaps, ducts for ventilation purpose.
  • Shut down all fans, blowers, pumps, purifiers, motors by remote stop device situated on upper deck.
  • Shut down fuel supply by quick closing valves.
  • Follow instruction for operating pilot cylinder for gang release and there after the master valve.
  • Use boundary cooling and observe fire and rescue procedures.

Q: what are the safeties incorporated in co2 system? How it works?

  • Relief v/v on manifold, rupture disk for cylinders
  • Interlock for fan, pump and  purifiers stop
  • Audio-visual alarm sounds while operating lever box is opened.
  • Overriding procedure for releasing, if pilot release fails to operate
  • Co2 cylinders are stored to maintain temp below 55°c and at 52 bar. If pressure rise above 177 bar at temp 63°c or above, rupture disk on cylinders opens. This gas is released through safety valve on manifold.

Q: When the co2 cylinder require recharging? How the content be checked?

  • Re-charge when weight reduce by 10%
  • Check by weighting, or radio active level indicator or ultrasonic gauging.