Auxiliary Systems Flashcards
How many bar of pressure does the high pressure salt water system maintain to a ring main?
7 Bar
How is the high pressure salt water system pressure supplied?
By electrically driven pumps, through a strainer and and connected via a “riser”
How is the high pressure salt water system pressure maintained?
Relief valves and 10% leak off valves
List 7 high pressure salt water system uses.
Firefighting
Pre wetting system
Fitted bilge and salvage educator’s
Emergency cooling to main propulsion turbine/diesel generators
Auxiliary machinery cooling water system
Making of fresh water
Flushing heads
How many pumps are running in damage control state 3 (DC state 3)?
One, with the others being maintained in a stand by state.
Special operations may require more pumps to be running. Give an example of an operation that would need these
Flight deck operations
How can pumps be started?
Locally (at the pump control box) or remotely (SCC or machinery Control Room)
A fixed firefighting system that can be automatically or manually operated would be used in areas of high fire risk such as?
Magazines
Paint lockers
Inflam store
Funnel
Sea water is used to cool engine coolant via a heat exchanger. What mixture is engine coolant?
Fresh water and AL39.
Name two reasons for fresh water circulation systems.
Machinery is susceptible to salt water corrosion
Other equipment can be affected by salt water contamination e.g. gas turbine, fuel systems and electric motors
What may happen if machinery is not cooled correctly?
Fires
Equipment failure
Wiping of bearings
Equipment seizing
At what temperature do white metal bearings melt?
115 degrees C
Lubrication/AL39 Systems are ……….. Loop.
Closed loop.
Cooling circulation systems are ………. Loop.
Open loop.
Machinery supplied by the main propulsion cooling system include
Lub oil heat exchanger
Gas turbine heat exchanger
CPP unit heat exchanger
Plummer block heat exchanger
Name two pieces of machinery supplied by the aux circ system
Air conditioning plant
Diesel plant/Generators
The fresh water circulation system can be cross connected to salt water in an emergency but only with who’s permission?
MEO’s permission
Give an example of an emergency situation were the fresh water circulation system would be cross connected with the salt water system. ( With the MEO’s permission )
Fresh Water Pump Failure.
What is MARPOL?
Maritime pollution regulations
Within 12NM (nautical miles) the oil content in discharged water must not exceed …
15PPM
Within 12NM (nautical miles) what must the ship have in operation to discharge water?
An oily water separating filter with an oil discharge monitoring and control system.
More than 12NM (nautical miles) from land oil content must not exceed ….
15PPM
More than 12NM (nautical miles) from land the ship must have in operation an …..
Approved oil filtering system.
Who enforces the MARPOL regulations?
The international maritime organisation (IMO)
Name 7 special areas defined by the IMO relating to oil pollution regulations
Baltic sea
North West European waters
Mediterranean sea
Black sea
Gulf
Gulf of Aden
Carribbean
Name four main sources of contamination
Bilges
Fuel systems
Oil systems
CPP systems
Safe systems of work are in place to minimise risk of oil entering bilge, including:
(6 answers)
Keeping machinery spotless - helps identify leaks
Monitor lub oil ready use tanks and investigate any losses
No surfactants used, only kleen break wipes
AFFF, although only in real fire risk situations
Eductors to be manned when in operation
Maximise the use of shoreside facilities when alongside
Who’s responsibility is it to be aware of the ships spill procedure?
Your own
Who must be informed of any MARPOL incidents?
MEOOD - Whilst alongside
MEOOW - Whilst at sea
Black water is defined as the drainage and waste from:
WC’s
Urinals
WC scuppers
Medical compartments
Any water mixed with this waste
What are the discharge regulations for black water within 4NM (nautical miles) of land?
Only permitted with an IMO approved sewage treatment plant (STP)
What are the discharge regulations for black water between 4NM and 12NM (nautical miles)?
Only permitted if an IMO approved system to comminute and disinfect the sewage is in operation
What are the discharge regulations for black water over 12NM (nautical miles)?
No treatment is necessary
Grey water is defined as waste from:
Bathrooms
Galleys
Dishwashers
Laundries
Sinks
What are the discharge regulations for grey water?
There are no regulations concerning discharge of grey water at sea unless entering/leaving port and when alongside.
Why do we use vacuum pumping systems?
Because they have less moving/mechanical parts.
Vacuum pumping systems (VPS) consist of a “fitted for ship” set of:
Diesel or electric driven pumps and manifolds and hoses
Vacuum pumping systems enable black and grey water to…
Be collected and pumped to the available shore facility.
Define bilge
Spillage, leakage, condensation that accumulates at the bottom of the hull
Define sullage
The left over fluids/sludge after bilge water has been passed through a separator
What are eductors used for?
To remove quantities of fluid, generally oil/fuel/water, from bilges very quickly.
Why does excess liquid build up in the bilges?
Leaks
overflows
machinery discharges
scrubbing down and washing through
What is the purpose of the bilge system?
To remove excess fluid from machinery space bilges to separate water from oil and discharge oil to sullage tanks by means of an oily water separator, with the water being discharged over board.
What is the purpose of the sullage system?
To retain dirty or waste oil/fuel until it can be properly discharged ashore.
Discharge from the bilge system is directed to the tanks of the sullage system or overboard when it does not contain oil/fuel and complies with MARPOL regs.
What is the correct order for opening the valves of an eductor?
- Open the discharge overboard valve
- Open the motive water valve from the HPSWM
- Open the bilge suction valves
What will happen if the eductor system is opened in the wrong order?
The compartment will flood with sea water from the HPSWM.
Who’s permission must you obtain to use an eductor?
The MEO’s.
The discharge of raw sewage close to shore creates both a health hazard and aesthetic problems along coastlines and on beaches name 3 health hazards from raw sewage.
Typhoid
Hepatitis
Gastro-enteritis
Name 6 advantages of using a sewage treatment plant (STP)
To reduce the number of ship side openings
To simplify pipe runs
Heads and bathrooms can be lower within the ship
The ship can operate in anti pollution areas
It is easier to close down in CBRN conditions (heads can still be used)
Describe step by step the operation of a biological STP (You may be asked to draw this)
- Black water enters the coarse screen via a macerator removing large particles.
- The waste enters the aeration compartment with the aeration diffusor passing oxygen through the waste.
- Undigested waste sinks to the bottom with digested waste floating above, starting to separate.
- The air lift pump transfers digested waste into the settlement hopper where heavy sludge will sink to the bottom and a clear liquid (effluent) floats on top.
- the effluent weirs across into the chlorine contact bank and then continues into the collection tank.
- Grey water is added to the collection tank diluting the high chlorine concentration whilst also disinfecting the grey water. The waste is now clean enough to discharge overboard.
- Whilst the sludge at the bottom is returned to the aeration compartment via an air lift pump.
The action of digesting the sewage is known as …
Hint - we promote this by pumping air in.
Aerobic digestion
If the air supply fails during the digestion of sewage the microorganisms will die giving off a gas smelling like rotten eggs. This process is called ….
Anaerobic digestion.
Collect hold and transfer is a fully automated system whereby the sewage is collected in large tanks with a storage capacity of about 12 days.
Explain the collect hold and transfer system (you may need to draw this)
- Special pumps create a vacuum in an initial collection tank with a 1 day capacity. This tank is connected to the WC pans by pipework also under vacuum ready to be drawn to the tank.
- Working on “Level switches” a combined discharge/transfer pump, when activated transfers the sewage to the larger holding tanks where it remains until discharged, either to sea outside the limit or to a shore reception facility.
- To prevent the sewage from turning “anaerobic” it is circulated between the tanks by means of an ejector which aerates the sewage slightly.
What gas is given off and must be monitored during biological breakdown?
H2S (hydrogen sulphide)
What does H2S (hydrogen sulphide) smell like initially?
Rotten eggs
H2S
…..PPM is detectable by colour
0.03ppm
H2S
…..PPM there is a long term exposure limit LTEL of maximum 8 hours
10ppm
H2S
…..PPM odour becomes sweetish
20-30 ppm
H2S
…..PPM odour becomes less detectable due to sense fatigue
Above 30 ppm
H2S
…..PPM kills sense of smell in about 3-15 mins, irritates eyes, throat and lungs
70-150 ppm
H2S
…..PPM immediate threat to life rapidly produces unconsciousness, permanent brain damage is possible
700-1000 ppm
H2S
…..PPM immediate unconsciousness and death within seconds
Over 1000 ppm
What is the main hazard of methane?
It is flammable and therefore is a risk of explosion
What is the main hazard of chlorine?
If inhaled will burn the lungs and can be fatal (WW1 CHEMICAL WARFARE)
Name four advantages of compressed air
Easily distributed throughout the ship
Can be easily stored
Flexibility and reliability of use
Low risk of fire
What 2 distinct categories can high pressure air be divided into?
HP air operating at 276 bar
Reduced HP air operating below 276 bar as required by specific equipment
Which two areas can HP air be divided into?
IMS ( inside machinery space )
IMS ( outside machinery space )
Name 8 uses for HP air
Diesel engine starting
Gas turbine starting
Ship siren operation
Breathing apparatus charging
Weapon system operation
Hydraulic system accumulator charging
Air driven machinery operation
Cross connection to low pressure air system (276 to 8 bar)
HPAC (high pressure air compressor)
Compresses the air in four stages (4 pistons starting larger, getting smaller)
What pressure is each stage?
Stage 1 - 4 bar
Stage 2 - 17.5 bar
Stage 3 - 68 bar
Stage 4 - 276 bar
