Auxiliary systems 3 Flashcards
what does HPSW stand for?
High Pressure Salt Water
what is the pressure of the HPSW main ?
7 bar or 100-120 PSI
what is the 7 uses of HPSW?
firefighting
prewetting system
bilge and salvage Eductors
emergency cooling
auxiliary machine cooling
making fresh water
flushing heads (only some ships)
describe the HPSW system.
A ring of pipework running around 2 deck that can be sub divided using isolation valves.
why do we need HPSW pumps?
to supply the ring main with high pressure salt water
special operations may need multiple pumps running but normally is only one.
what are the two setting on a pump starter?
local : controlled close to the pump
remote : trigger in SCC
describe how a HPSW pump works and prevents over pressure
takes its suction from the sea through a strainer discharging to the riser which then goes to the ring main
also has a 10% leak off to prevent over pressure
what compartments are sprays used in?
magazines
paint lockers
Inflam store
funnels
what is prewet?
spraying HPSW on the upper deck to wash chemical and contaminates of in a CBRN environment.
what is the HPSW configuration for Damage control state one?
action stations
all HPSW pumps running
DC state 1 valves are shut
HPSW is divided into zones
what is the HPSW configuration for Damage control state three?
one pump running others in standby
all DC state valves are open.
what temp do white metal bearings melt at?
115degrees c
what happens to machinery that is not cooled? (4)
temp will rise until it
fails
seizes
destroys bearings
catch fire
what does the main circulation system cool? (4)
gas turbines
emergency Plummer block cooling
main Forced Lube system
Controllable pitch propeller
why is the cross connection important in the main circulation system?
it allows for the port or starboard cooling system to share HPSW if one of the strainers is blocked
needs MEO’s permission
same with emergency cooling
what does the auxiliary cooling circulation system cool?
Air Conditioning Plant (ACP)
Diesel generator(DG)
What is the main circulation cooling system?
The main cooling system for the boat.
what type of system is the freshwater / salt water cooling circulation system.
closed loop.
why do we use fresh water rather then salt water for cooling?
as fresh water is less contaminated the SW so there is less corrosion in machinery which could damage it .
what is the regulation we comply with to do with the enviroment?
maritime pollution regulation 1973/78
when can you discharge oil or oily mixtures?
when ship is underway
if the oil content is under 15ppm without dilution
ship must be fitted with oily water separating filter and oil discharge monitoring and control system.
where is the one place discharge of oily water is prohibited?
Antarctica area
what are special areas under MARPOL?(9)
Baltic sea
north west waters
Mediterranean sea
black sea
gulf
gulf of Aden
Caribbean
Oman area of the Arabian sea
SOUTH AFRICAN WATERS
What are the sources of oily water contamination?(4)
bilges
fuel systems
oil systems
CPP systems
how do we keep bilges clean from oil and contaminates? (6)
keep machinery spotless
monitor lube oil ready use tanks
no surfactants (kleen break only)
AFFF only to be used in real fires (not drills)
Eductors to be manned when in operation
maximise the use of shoreside facilities
what is the procedure following a spill?
let the OOD(in harbour) or OOW (at sea) know about any MARPOL incident
what is black water?
waste from WC, urinals, WC drains, medical compartments.
what is grey water?
water from showers, galley, laundry’s
what is the regulation around black water?
can be discharged
within 4NM of the coast if a IMO approved sewage treatment (STP)
between 4-12NM of the coast if a approved system to dilute and disinfect the sewage
over 12NM from the coast no treatment
what does IMO stand for?
International Maritime Organisation.
when can you discharge grey water?
any where apart from ports or harbour.
what is the vacuum pumping system (VPS) used for?
a set of
diesel / electric pumps
manifolds and hoses
which black and grey water is discharged to shore facilities
what is the job of a bilge Educator?
removes fuel oil and water from a bilge and discharges overboard
what is the job of the bilge system?
separates oil from the water in the bilge and discharges the oil into the sullage system and water overboard
what is the job of the sullage system?
holds oil and waste from the bilge whilst under way to be pumped out once alongside.
what are Educators?
a piece of kit that sucks large amounts of water from bildges.
how do you operate the Educator valves and why do you do it in this order?
open the D.O.B valve
open the motive waster supplied from HPSWM
open the bilge suction valve
keep manned
could flood the bilge if opened in the wrong order
only operated with MEO’s permission
what are the hazards of the bilge and sullage system? (4)
fire and explosion risk
toxic gases
affects stability
flood risk
what are the advantages of HP air?
easily distributed throughout the ship
easily stored
flexible and reliable
low fire risk
what is the operating pressure of HP air
276 bar
what two area is HP air split into?
Inside Machinery Space(IMS)
Outside Machinery Space(OMS)
what are the uses for HP air? (7)
diesel generator starting
gas turbine starting
ship siren operation
breathing apparatus charging
hydraulic accumulator charging
air driven machinery
cross connected to LP air
what is the pressure in each stage of compression of HP air and the relief valve value?
1st stage
4bar
relief 4.4bar
2nd stage
17.5 bar
relief 19.25bar
3rd stage
68 bar
relief 74.9bar
4 stage
276 bar
relief 303.6
relief is +10% of compression
what is the safety relief pressure of the water jacket?
3.5bar
what pressure is LP at?
8bar
what is LP air used for?
emergency stern seal
pneumatic tools
radar waveguides
pneumatic surveillance
what PPE is need to work with HP and LP air?
ear defenders
googles
overalls
DMS boots
what are the hazards of HP air?
dieseling (explosions)
physical damage
what are the health hazards with raw sewage?
Typhoid
Hepatitis
Gastro-Enteritis (D and V)
why do we have STP’s? (5)
reduce the number of ship side openings
simplify pipe runs
heads and bathrooms lower in the ship and can be used in drydock
ship can operate in anti pollution zones
easier to close down in CBRN environment
why do we need aerobic Bactria in sewage treatment?
as they are need to break down raw sewage with out creating H2S.
why do we need Aeration diffusers in STP’s?
to aerate the sewage so that the bacteria needed to break down sewage can be kept alive other wise Hydrogen Sulphide is created a toxic gas that smells like eggs.
why is there isolation valves on each tank in the STP?
so that you can discharge sewage at any stage of the process depending on how far from land you are.
what is the job of the coarse screen?
to filter large pieces of sewage from the black water tank.
how does the broken down sewage get to the separation hopper and what is its job?
a air lift sucks up the sewage and so it can settle in the hopper to be drained
how is sewage collected in the CHT system?
specials pumps draw a vacuum into the collection tank
what is the capacity of the collection tank?
1 day
how do we transfer between the collection tank and the holding tank?
level switches activate a transfer pump with pumps it between the tanks.
what is the capacity of the holding tank?
12 days.
how do we prevent sewage turning anaerobic in a CHT system?
sewage is circulated between tanks by a ejector which slightly aerates it .
what are the hazards with STP’s
raw sewage
dangerous chemicals - calcium hypochlorite
dangerous gases- HS2,Methane and chlorine
what is the effect of 0.03 PPM of hydrogen sulphide?
smells like rotten eggs
what is the effect of 150-400 PPM of hydrogen sulphide?
loss of smell, dizziness, coughing, difficulty breathing
what is the effect of 1000 PPM of hydrogen sulphide?
immediate unconsciousness and death
label this diagram
label this diagram
label this diagram
what is the chlorine contact used for
sterilises any remaining dangerous bacteria
what is the funny number
69 nice
(this is the 69th flash card
