Oral Prep
Q1. Power distribution
a) Draw a power distribution diagram
b) What planned maintenance is done on the power distribution system?
c) What is a shore supply? What is it used for?
d) How do you connect to shore supply? What are the main things you should check before
connecting? Where would you connect?
e) What fault prevention methods are used and how are they tested?
f) What trips are in place on a distribution system?
g) Why is an undervoltage trip needed?
h) What is a preferential trip?
i) How do you manually sync generators?
j) What is a synchroscope? Why must it be switched off after use?
k) What does it mean if the synchroscope is moving fast in an anticlockwise direction?
l) What does it mean if the synchroscope has stopped in the 6 o’clock position?
m) Does the synchroscope show the direction of the generator shaft?
n) What are the dangers of trying to put a generator on the board that isn’t synchronised?
What should happen if you try to do this?
o) What are the procedures following a blackout?
p) What do transformers do and how do they work?
q) What are bus couplers for?
r) Why use breakers instead of switches?
s) What is a PMS? What does it do?
t) What measures are in place to limit fault currents on high and low voltage switchboards?
u) What is an earth fault? How can it affect the running of the ship?
v) How do we know if there is an earth fault?
w) How can you locate earth faults?
x) Why are earth fault detection meters more effective than earth lamps?
y) How to earth lamps work? How do you know you have a fault?
z) What test equipment should be used to trace earth faults?
aa) What are essential, non-essential and emergency loads?
bb) Why are generators, transformers and distribution boards generally rated in kVA?
cc) What is a mains failure relay?
dd) Is there such thing as over voltage? If so, what is it?
ee) Are the electrical systems on a normal low voltage ship earthed?
ff) What would one fault on one phase of a neutral insulated system cause to happen? What
would two faults cause to happen? Would you know there was two faults?
gg) What are harmonics? How are they reduced?
hh) What is the acceptable minimum limit for insulation resistance on a low voltage system?
ii) What factors contribute to deterioration of insulation in an electrical system?
Q2. Generators
a) What planned maintenance is done on a generator? What safety precautions should be
taken before doing maintenance?
b) How does a generator work?
c) What is an AVR? What does it control?
d) What two types of rotor construction are generally used with rotating field armatures?
e) How do you manually control the speed of a generator?
f) What does the governor control?
g) What is droop?
h) What is a trimmer?
i)
j)
k)
l)
m)
n)
o)
p)
What is a power factor?
How to we improve power factor?
What trips are on a generator engine?
What is needed to run a generator?
No voltage causes on a generator?
Where is the residual magnetism in a generator?
How do you field flash?
How can you share load manually between 2 generators? What equipment would you
monitor while you do this?
q) Which controls are adjusted to ensure proper kW and kVAr load sharing takes place? How
do they work?
r) Every time you try and connect the generator manually, it keeps tripping back out. What
could be the problems?
s) What is reverse power? How is it caused?
t) What are the diodes for in the excitation circuit?
u) 2 generators are on the board running at 62Hz. How would you reduce their frequency?
v) What is sequential starting and when should this occur?
w) What is a compounded AC generator?
x) What factors govern the overall voltage response of a generator to sudden load changes?
y) What types of sensors would you expect on a generator?
z) How to the temperature sensors control aspects of the engine such as JW cooling and EX
temp?
aa) What temperatures and would you expect to see for EX temp, JW cooling temp and lube oil
temp?
bb) What pressures would you expect to see for fuel oil and lube oil?
cc) What control measures are in place to share load evenly between 2 generators with
different maximum powers? E.g 2 different engines with 2000kW and 1500kW
dd) What is an oil mist detector? How can this be tested?
ee) What is the relationship between poles, frequency and speed?
ff) What does turning gear do and when should it be used?
gg) If an alarm was set off on a generator, would the generator shut down?
Q3. Emergency Generator and Switchboard
a) Emergency generator regs and what it does?
b) What tests would you do on the emergency generator? How often?
c) How can you start an emergency generator?
d) How do you test the automatic start on an emergency generator?
e) How long should it take to start after a blackout? 45 Seconds
f) How often should the emergency generator be tested?
g) What services does the emergency generator supply? SOLAS required equipment?
h) Where are emergency exit lights and signs powered from?
Internal Battery supplied from EM SWBD
Q4. Propulsion
a) Types of speed control?
b) Differences between types of speed control?
c) What are the main types of thrusters on ships? How do they work?
d) What is pulse width modulation? Why is it converted back into AC? Draw a typical wave
form for PWM.
e) Explain commutation.
f) What is regenerative braking? What types of drive system can this be used on?
g) How would you make a PM ready for use? What interlocks might be in place for the PM
breaker to close?
Q5. Motor Starters
a) Draw a typical circuit diagram for a motor with a direct on line starter.
b) What is the control circuit? What does it do?
c) What is the typical starting current for an asynchronous motor with a DOL starter?
d) How would you change the direction of a 3 phase motor using components and not just
switching the lines around?
e) Causes of tripping
f) What is an OCR?
g) What is a differential OCR?
h) Why doesn’t the OCR trip during starting?
i) What can cause an OCR to fail?
j) Why is the manual resetting of an OCR important?
k) What is the inverse time characteristic?
l) What is a fuse?
m) What should the rating of the fuse be?
n) What fuses should a motor with a running current of 15A and a starting current of 90A have?
o) What is the difference between a fuse and OCR?
p) How can you reduce the starting current of a motor?
q) What is the starting current for a star-delta starter?
r) What is the time delay when switching between star and delta?
s) What happens if a motor gets stuck in star configuration?
t) What happens if all 3 contactors get stuck in?
u) Draw a typical circuit diagram for a star-delta motor starter or an autotransformer motor
starter.
v) What is the starting current for an autotransformer starter with a tapping of 50%?
w) Describe how a soft start starter works.
x) What kind of under voltage protection is there in a motor starter?
y) What are the problems with starting a large motor?
z) What are the relationships between star and delta regarding current and voltage?
aa) When replacing contacts in a starter, how many would you replace and why?
Q6. Motors
a) How does a motor work?
b) What planned maintenance is done on a motor?
c) How can you improve the power factor of a motor?
d) What is a synchronous motor?
e) What is an asynchronous motor?
f) Why would it be beneficial to do an IR test on a motor while the motor is still hot?
g) How would you overhaul a motor that has been flooded with sea water?
h) What would a clamp ammeter read if it was clamped around a 3 core cable connected to a
motor known to be carrying 100A?
i) How could you detect if a motor is single phasing?
j) How do you change the bearings on a small motor?
k) How often should an electric motor be cleaned?
Follow manufacturers guidelines and clean for every Planned Maintenance
Q7. Circuit Breakers
a) Which kind of circuit breaker is mainly used on a low voltage switchboard?
b)
c)
d)
e)
f)
What kind of maintenance is done on a circuit breaker?
What are the main features of a circuit breaker?
What is the most important rating on a circuit breaker? Why?
What is the main advantage of a circuit breaker over other devices?
A breaker on the switchboard won’t close. What could be the problem?
Q8. High Voltage
a) Why is high voltage used?
b) Explain how to safely isolated a transformer.
c) How is earthing achieved on a HV system?
d) How do you use a HV testing probe to prove a circuit is isolated?
e) What kinds of circuit breakers are used on a HV system?
f) How do ACB’s dissipate an arc?
g) What is a CME?
h) What is a NER?
i) Why is a NER used?
j) What is a sanction to test?
k) What voltage is considered high voltage?
l) What voltage would be used to IR test on a 3.3kV HV system?
m) What is the most common planned maintenance for on a HV system?
n) Why is a HV system not isolated from earth?
o) What is the acceptable minimum limit for insulation resistance on a HV system?
Q9. Steering gear
a) What is the steering gear? What does it do?
b) Describe the main features on the steering gear.
c) What maintenance is carried out on the ships steering gear?
d) What are the 2 main types of steering gear?
e) What are the regulations regarding steering gear?
f) How would you know if a steering gear motor was single phasing? (Theres no OCR)
g) Where will at least 1 steering gear motor be powered from?
Q10. Batteries
a) What safety precautions should be taken before work is done on a battery?
b) What is considered a typical voltage for a fully charged lead acid battery?
c) What is an acceptable number for the specific gravity for a fully charged lead acid battery?
d) What is an acceptable number for the specific gravity for a discharged alkaline battery?
e) What is an acceptable number for the specific gravity for a charged alkaline battery?
f) Should the specific gravity change for either battery?
g) What are batteries used to supply on ships?
h) What first aid treatment should you apply if someone is splashed with acid or alkaline from a
battery?
i) Why should lead acid and alkaline batteries never be stored near eachother?
j) What are the advantages and disadvantages of using lead acid batteries over alkaline
batteries?
Q11. Transformers
a) What do transformers do?
b) What kind of maintenance is done on a transformer?
c) What precautions should be taken when isolating a transformer to do carry out maintenance
on?
d) What is an isolating transformer?
e) How would you IR test a transformer?
Q12. Bridge Equipment
a) What is an ECDIS?
b) What is an SVDR? What information is fed into an SVDR?
c) The SVDR is in alarm while the ship is in port. What could be the problem?
d) What is a radar? How does it work?
e) What should happen to bridge equipment during a blackout?
f) What is a Doppler log? How does it work?
g) What is an echo sounder?
h) The echo sounder is on in port but nothing happens, what could be the problem?
i) What tests would you do on a GMDSS?
j) Draw a typical circuit for navigation lights. How would you know if there is a fault?
k) What is auto pilot? How does it work?
l) What equipment is required to work in order for a ship to sail?
m) What is AIS? Should it be switched off in port?
n) What are NUC lights and where are they powered from?
Q13. Fire Fighting and Fire Safety
a) What fixed installations can be used on a ship?
b) What type(s) of extinguisher can be used on an electrical fire?
c) What type(s) of extinguisher can be used on a fuel oil fire?
d) How do you use a water fire extinguisher?
e) What precautions should be taken when using CO2?
f) Who is in charge of the operation of the ships CO2 system?
g) What is the ETO’s role in a fire onboard a ship?
h) What kinds of fire detector heads are used and how are they tested?
i) What kinds of detection components are used other than smoke, heat and flame detectors?
j) How often should the fire detection system be tested?
k) You find a fire in the galley. Go through the procedures of what you would be expected to do
in this event?
l) What tests should be carried out on a BA set before using it?
m) What are the main causes of engine room fires?
n) What pumps can be used to supply water to the fire main?
o) Where are the fire pumps supplied from?
p) Where would you usually find the emergency fire pump?
Q14. Lifesaving apparatus
a) How much water ration per person is in a lifeboat?
b) What kinds of flares are there on a lifeboat and how many of each?
c) What is a sea anchor and what is it used for?
d) What is a TEMPSC?
e) What is the maximum time it should take to launch a fast rescue craft?
f) What checks should take place before entering and lowering a lifeboat?
g) What would you do if you heard 3 short blasts and 1 long blast on the ships whistle?
h) What would you do if you heard 7 short blasts and 1 long blast on the ships whistle?
Q15. First aid
a)
b)
c)
d)
What kind of injuries could arise from electricity?
How would you treat someone having a heart attack?
How do you control bleeding?
What is the first thing you should do if you find an unconscious casualty?
Q16. Hazardous Areas
a) What does “intrinsically safe” mean?
b) What is a hazardous area?
c) A piece of equipment has “EEx d IIC T6” written on it. What do these figures mean?
d) What are zones?
e) What do the temperature groups mean?
f) What kind of hazardous area equipment would you expect to find in use in a paint store?
Q17. Boilers
a) What types of sensors would you expect on a boiler?
b) What safety devices would you expect to find on a boiler?
Q18. Refridgeration and AC
a) Name the electrical components usually found in a refridgeration or AC system.
b) What is a compressor?
c) If a compressor is switching on and off – is it fair to think the problem is the motor itself?
What else could be the problem?
d) What could be happening to the motor from constantly switching on and off?
e) If the contactor is stuck closed, what could this cause?
f) Why would a compressor run hot?
Q19. Miscellaneous Electrical
a) What is a short circuit fault? How do you test for this?
b) What is an open circuit fault? How do you test for this?
c) How would you safely isolate a piece of equipment? e.g. a Transformer
d) What is a live line tester?
e) What is a UPS? What does it do?
f) What services rely on UPS systems?
g) What is a diode?
h) What is a transistor?
i) What is a thyristor?
j) What is a PI index?
k) What is IR testing? What voltages should be used?
l) How does an IR tester work?
m) Where are earth faults most likely to occur?
n) In what circumstances is working on live equipment permitted?
o) How can you test a fuse?
p) How does a fluorescent light work?
q) What would you expect was wrong if a fluorescent light kept flashing when it was switched
on?
r) What is the capacitor for in a fluorescent light circuit?
s) What happens if you remove the starter from a fluorescent light while it is lit?
t) Do ammeters on the MSWB panel and on starter panels carry full load currents? How?
u) What is a current transformer?
v) What is low location lighting?
w) What types of sensors would you expect to find around the ship?
x) How do you test these?
y) What is the alarm system? What does it do? How does it work?
Q20. Miscellaneous
a) What is cathodic protection?
b) What is a watertight door? Explain how a watertight door is safely operated. Where can they
be operated from?
c) What is a permit to work? When should they be used?
d) What should be done prior to obtaining a permit to work?
e) What permit might you need for working up the ships mast? What safety equipment would
you use?
f) What precautions should be taken before doing work in an enclosed space?
g) How would you control an oil spill?
h) What is an oily water separator?
i) What is lifting gear? How is it rated? How is it tested? What is the colour coding scheme?
j) Chief engineer tells you to do work on a lift and you don’t have a permit to work. What do
you do?
Q21. Regulations
Q1
(a) Draw a power distribution diagram
(b) What planned maintenance is done on the power distribution system?
Safety – Isolate, Lock and Tag out and Prove equipment dead, Wear PPE – Electrical Gloves
Visual Inspection – Look for signs of overheating or burning on bus bars, cables, insulators
Ensure all connections are tight and no loose connections
Clean switchboards with a vacuum cleaner
Clean contactor with fibreglass cleaning pen
Clean Arc Chutes
Check Insulation Resistance of equipment to ensure to connection to ground.
Check continuity of equipment to ensure no open circuit.
Testing trips on ACB, Fuses, Thermal Camera,
Generators, Bus Bar, Bus Tie, Transformers; HV Equipment, LV Equipment, Emergency Swbd
Interconnector.
(c) What is a shore supply? What is it used for?
When a ship is berthed, the port might require a shore supply connection. This is a 3-phase
connection from a land based power grid that supplies the ships power distribution. This saves fuel
consumption and also prevents air pollution or noise of the ships generators.
(d) How do you connect to shore supply? What are the main things you should check before
connecting? Where would you connect?
A shore supply is connected using a land based 3-phase the shore supply. Before connecting to a
shore supply you must match the Voltage, Frequency and Phase Rotation. A shore connection box is
usually fitted in the cross alley on the main deck. The connection is commonly a socket type
(e) What fault prevention methods are used and how are they tested?
Undercurrent/Overcurrent – Current Transformers (CT’s) are used to monitor the current flowing in
a circuit. If the current reaches a set value above of below the rated current an alarm will be
activated and if the fault persists the faulty circuit will be tripped by the overcurrent relay. This can
be tested by injecting a test current through the relay.
Earth Fault – Earth Fault Monitors operate by connecting a small DC voltage to the distribution
system. Any resulting DC current is a measure of the insulation resistance system.
(f) What trips are in place on a distribution system?
Short Circuit – Fuse: A safety device made of a strip of wire that breaks a circuit if the current
exceeds a safe level.
Under Current/ Over Current – OCR
Undervoltage/Overvoltage
Under Frequency/Over Frequency
(g) Why is an undervoltage trip needed?
An Undervoltage protection relay is important as it can protect against Short Circuit faults. Short
Circuit reduced voltage to zero and Undervoltage relay trips the breaker.
(h) What is a preferential trip?
A Preferential Trip is a set sequence that trips non-essential consumers in the event of a generator
overload. This reduces the generators load so that essential consumers continue to be supplied. The
preferential trip usually has 3 stages.
E.g. Stage 1 @ 5 sec – Galley & Laundry Equipment, Stage 2 @ 10 sec – Air Conditioning, Stage 3 –
Cargo Pumps and Bow Thruster
(i) How do you manually sync generators?
The generator already connected to the bus bars is called the running machine and the generator to
be brought into service is the incoming machine. The following conditions are essential before
closing the incoming machine breaker:
1. Same voltage, 2. Same frequency, 3. Same phase sequence.
Excitation current varies the voltage of the incoming machine. This is done by the AVR but can be
manually trimmed. The governor of the generator controls the frequency of the incoming machine.
This controls the amount of fuel allowed into the generator and thus either speeds up or slows down
the generator. The speed of the incoming machine should be just a little bit faster than the running
generator so that it will take up load once paralleled and load sharing. Using the synchroscope and
the governor (speed) control, get the incoming machine to start rotating clockwise slowly. When the
synchroscope pointer reaches the “5 minutes to 12” position, close the incoming machines circuit
breaker.
(j) What is a synchroscope? Why must it be switched off after use?
A synchroscope is a device used when paralleling generators that monitor the speed of an incoming
generator relative to a running generator or bus bars. The synchroscope is powered off after use
because the electronic components aren’t rated for continuous use and there is no purpose of
leaving it switched on.
(k) What does it mean if the synchroscope is moving fast in an anticlockwise direction?
If a synchroscope is moving fast in an anticlockwise direction, the incoming generator is running
slower than the running generator or bus bars frequency.
(l) What does it mean if the synchroscope has stopped in the 6 o’clock position?
If the synchroscope is stopped at the 6 o’clock position the incoming generator and running
generator are at the same speed or synchronized.
(m) Does the synchroscope show the direction of the generator shaft?
No, the synchroscope shows the direction of rotation and the speed of the incoming generator
relative to the running generator or bus bars.
(n) What are the dangers of trying to put a generator on the board that isn’t synchronised?
What should happen if you try to do this?
Connecting a generator which isn’t synchronized can cause great damage to the generator as a huge
mechanical stress will act on the shaft and can damage the generator or alternator. A “Synch-Check”
relay is installed to prevent this from happening and only allows the breaker to be closed when the
two generators are in phase.
(o) What are the procedures following a blackout?
Call Master to the Bridge and Chief Engineer to Engine Room.
Ensure ship isn’t in a dangerous area and there’s no traffic in the area.
Emergency generator is run up and connected within 45 seconds. Manual Steering is now available.
Sequential restart will start –> 0 sec – F.O. pump, Steering gear
5 sec – L.O. pump
15 sec – Feed Water Pump
25 sec – CFW Pumps
35 sec – CSW Pumps
40 sec – E/R Vent Fan
Now start other consumers and get plant under normal operation.
(p) What do transformers do and how do they work?
A transformer is an electrical device that takes electricity of one voltage and changes it into another
voltage (e.g. 6.6 kV to 440 V). The AC voltage on the primary winding creates an alternating magnetic
flux around a steel core. The flux induces an EMF in the secondary winding and its voltage depends
on the ratio of the number of turns.
(q) What are bus couplers for?
A bus coupler or bus tie is a circuit breaker that connects one switchboard to another. These are
operated when one of the switchboards are undergoing maintenance.
(r) Why use breakers instead of switches?
Breakers are used instead of switches because they can automatically disconnect circuits if a fault
occurs.
(s) What is a PMS? What does it do?
A Power Management System (PMS) is a computer system that controls the ships electrical system.
It keeps the system running efficient and safely. The PMS monitors and controls Load Sharing,
Starting and Stopping of the Generators, Automatic Blackout Restart.
(t) What measures are in place to limit fault currents on high and low voltage switchboards?
(u) What is an earth fault? How can it affect the running of the ship?
An earth fault occurs when a live conductor comes into contact with earth such as its metal
enclosure. If an earth fault appears on a system its important to remove it fast because if there are
two earth faults present on different phases a short circuit will be made.
(v) How do we know if there is an earth fault?
Since ships use an insulated electrical system to maintain continuous supply for essential consumers,
they are fitted with earth fault monitors. These show the Insulation Resistance (IR) of the system.
This is done by connecting a small DC voltage to the distribution system and any resultant DC current
is the insulation resistance of the system.
(w) How can you locate earth faults?
To find an earth fault can take a lot of time as you have to open the circuit breaker of each machine
connected to the switchboard while watching the IR meter to see if the earth fault has cleared. This
also takes cooperation from the engineers as they may have to changeover machines from one
switchboard to the other.
(x) Why are earth fault detection meters more effective than earth lamps?
Earth Fault Lamps are not very sensitive and don’t indicate high impedance earth faults.
(y) How to earth lamps work? How do you know you have a fault?
If the system is healthy the Earth Fault Lamps will be equally bright at half brightness. If an earth
fault occurs on one line, that line’s lamp will go dark and the other lamps will show brighter.
(z) What test equipment should be used to trace earth faults?
A Insulation Resistance Tester (AKA a Megger) is used to test the insulation resistance of machines. A
healthy machine will have a very high Insulation Resistance (>10MΩ) and a machine with an earth
fault will show a very low Insulation Resistance (10Ω).
(aa) What are essential, non-essential and emergency loads?
Essential – This is equipment that is essential for the safety of the vessel e.g. Steering Gear, NonEssential – This is equipment that is not essential for the safety of the vessel e.g. Air Conditioning,
Emergency – This is equipment that is used in an Emergency e.g. Emergency Fire Pump.
(ab) Why are generators, transformers and distribution boards generally rated in kVA?
These are rated in kVA because the power factor depends on the load. I2R losses depend on
the current flowing. So the Active Power will vary as the load changes so a rating cant be
given in kW.
ad) Is there such thing as over voltage? If so, what is it?
Overvoltage is when the voltage in a circuit is raised over its rated limit. E.g. if the voltage of a 440V
circuit reaches reaching 450V.
ae) Are the electrical systems on a normal low voltage ship earthed?
No, low voltage ships are usually insulated systems so the electrical system in totally
insulated from earth.
af) What would one fault on one phase of a neutral insulated system cause to happen? What
would two faults cause to happen? Would you know there were two faults?
One earth fault will show a fault is present on the switchboards Insulation Resistance Monitor
as it will go low. In the event of an earth fault occurring on two separate phases a short circuit
will be made and the faulty circuits will be tripped.
ag) What are harmonics? How are they reduced?
Harmonics on an electrical system are made up of multiples of the
fundamental frequency (e.g. 60 Hz). The most powerful harmonics
in a 3-ph syster are the 5th, 7th and 11th. Having harmonics present
on an electrical system can cause a higher current and lead to
overheating.
Fitting harmonic filters, which are banks of capacitors, into the electrical system can reduce
harmonics. Fitting a diesel propulsion system with more pulses reduces harmonics, this can be done
by fitting more thyristors or using a transformer with a star and delta secondary winding.
ah) What is the acceptable minimum limit for insulation resistance on a low voltage system?
According to SOLAS requirements the formula 1kΩ/volt is used. So for 440V, an insulation
resistance of 440kΩ say 500kΩ is the minimum requirement.
ai) What factors contribute to deterioration of insulation in an electrical system?
Insulation of a cable is deteriorated with age. The insulation will also deteriorate if the cable
is exposed to hot or wet atmospheres.
Q2. Generators
a) What planned maintenance is done on a generator (alternator)? What safety precautions
should be taken before doing maintenance?
•
•
•
•
•
The generator should be isolated electrically and the prime mover should be isolated from
its starting source (compressed air) and fuel source (diesel) and prove dead electrically.
Make an inspection of the field and rotor windings, make sure there is no physical
connection and no hotspots.
Check the resistance on each phase (should be low 0.1Ω) and preform an insulation
resistance test using a 500V Megger. If the generator is high voltage use a 5000V Megger to
perform a PI (Polarisation Index) test.
Then preform an insulation test of the rotor (not forgetting to short out the rotating diodes
if present to save from blowing the arse of them)
Re-instate your generator and test idle.
b) How does a generator work?
•
•
•
•
•
A DC excited rotor is spun inside a set of field windings
the rotating DC rotor will cause an EMF to cut the field windings
this induces a voltage which is then fed through the lines to the supply
the power depends on the amount of fuel allowed to the engine which is controlled by the
governor
the terminal voltage depends on the excitation current which is controlled by the AVR
c) What is an AVR? What does it control?
An Automatic Voltage Regulator (AVR) is a unit that controls the excitation current supplied to the
rotor of the generator. Varying the excitation current controls the output terminal voltage of the
generator.
d) What two types of rotor construction are generally used with rotating field armatures?
Salient rotor types has projecting poles bolted or keyed onto the shaft field excitation windings are
fitted around each pole this typed of rotor is used with medium and slow shaft speeds
Cylindrical type rotors are generally used with large power high speed 1500-3600RPM steam/gas
turbine drivers
e) How do you manually control the speed of a generator?
By adjusting the generators governor. This is usually found on the main switchboard.
f) What does the governor control?
The governor controls the speed of a generator therefore the frequency is altered when being
adjusted. If the generator is paralleled with another generator the load on the generator will be
controlled by adjusting the governor.
g) What is droop?
Droop is used for a network of generators. It is a feature of a generator that controls the
amount of fuel allowed to the generator with a change in load. 60 Hz is the set frequency and
4% is a typical droop setting. So the set point will be raised or lowered by 4% to overcome an
increase or decrease in load.
Speed
12
10
Droop
8
6
4
2
0
0
5
10
15
20
25
30
h) What is a trimmer?
A trimmer is manual control on the AVR that allows you to fine tune the terminal voltage
output of the generator.
i) What is a power factor?
𝑇𝑟𝑢𝑒 𝑃𝑜𝑤𝑒𝑟 (𝑊)
PF = 𝐴𝑝𝑝𝑎𝑟𝑒𝑛𝑡 𝑃𝑜𝑤𝑒𝑟 (𝑉𝐴) Power Factor is the ratio of Real Power and Apparent Power. It
varies from 0 to 1 and is usually around 0.85 on a ship due to the amount of inductive loads
such as motors.
j) How to we improve power factor?
The ideal Power Factor is 1, which means there is no reactive power so all the power is real
power. This can be improved by connecting a bank of capacitors to overcome the inductive
load.
Another option is exciting a synchronous motor on the system.
k) What trips are on a generator engine?
Reverse power
Emergency stop
Overspeed
l) What is needed to run a generator?
Fuel (Diesel)
Starting Air
Lube oil
HT Cooling
LT Cooling
m) No voltage causes on a generator?
No rotor excitation
Open circuit on rotor or stator
Alternator is not turning
n) Where is the residual magnetism in a generator?
Residual magnetism is stored in the rotor iron core
o) How do you field flash?
If the machine does not have enough residual magnetism to build up to full voltage, usually
current is injected into the rotor from another source such as a battery. Since this initial
current is required for a very short time, it is called "field flashing". Even small portable
generator sets may occasionally need field flashing to restart
p) How can you share load manually between 2 generators? What equipment would you
monitor while you do this?
By increasing the governor setting on one generator this generator will start taking more load
and decrease the load on the other generator, this governor may need a slight decrease. You
would ensure the generator frequency is not being adjusted and stays set at 60 Hz.
q) Which controls are adjusted to ensure proper kW and kVAr load sharing takes place?
How do they work?
kW load is shared by controlling the generator speed (Fuel Governor)
kVAr load is shared by adjusting the alternator excitation current (AVR)
r) Every time you try and connect the generator manually, it keeps tripping back out. What
could be the problem?
Generator isn’t synchronized and check synch is blocking it from connecting.
s) What is reverse power? How is it caused?
Reverse Power is a fault that can occur on a generator. It can happen when 2 generators are
paralleled and if one generator isn’t taking enough load the leading generator will take all the
load and treat the other generator as a motor instead of a generator.
t) What are the diodes for in the excitation circuit?
The rotating diodes on the excitation circuit rectify the AC voltage induced from the
brushless excitation.
u) 2 generators are on the board running at 62Hz. How would you reduce their frequency?
Lower the governor fuel supply slightly on both generators
v) What is sequential starting and when should this occur?
Sequential starting is a process that starts machinery required to get the ships power plant
back to normal operation after a blackout.
w) What is a compounded AC generator?
An AC compound generator is a generator that is fitted with both Shunt and Series Field
Windings.
x) What factors govern the overall voltage response of a generator to sudden load changes?
The AVR, it should respond to a voltage change of up to 15% and bring it back down to
within 2.5% within 1.5 seconds
y) What types of sensors would you expect on a generator?
Jacket Water Cooling Temp – 60-75˚C
Fuel Press & Temp
Shaft RPM
Turbocharger RPM
Exhaust Temp – 400˚C - 600˚C
Oil Mist Detector
Alternator Cooling Temp
CT’s
VT’s
y) How do the temperature sensors control aspects of the engine such as JW cooling and EX
temp?
If the temperature of JW cooling gets too low it will be switched off until it reaches a set
point to turn back on.
z) What temperatures and would you expect to see for EX temp, JW cooling temp and lube
oil temp?
Exhaust Temp – 400˚C - 600˚C
Jacket Water Cooling Temp – 60-75˚C
Lube oil temp – 70˚-80˚C
ab) What pressures would you expect to see for fuel oil and lube oil?
FO – 1-2 Bar, LO – 3-4 Bar
ac) What control measures are in place to share load evenly between 2 generators with
different maximum powers? E.g 2 different engines with 2000kW and 1500kW.
Droop and Isochronous Load Sharing Controls
ad) What is an oil mist detector? How can this be tested?
Spray test gas with engine running idle to test shutdown
ae) What is the relationship between poles, frequency and speed?
𝑭𝒙𝟔𝟎
𝐹𝑟𝑒𝑞𝑢𝑒𝑛𝑐𝑦 𝑥 60
N=
=>
Speed (RPM) =
𝒑
𝑁𝑜. 𝑝𝑜𝑙𝑒 𝑝𝑎𝑖𝑟𝑠
af) What does turning gear do and when should it be used?
When shutting down the engine, the turning gear keeps the lube oil moving to slowly cool
down to ensure no hot spots.
ag) If an alarm was set off on a generator, would the generator shut down?
This depends on the fault, there are High (alarm) and High High (trip) faults.
Q3. Emergency Generator and Switchboard
a) Emergency generator regs and what it does?
Start once a month, Fuel = 18hrs for tankers 36 for cruise,
45 sec to automatically connect and power emergency loads.
b) What tests would you do on the emergency generator? How often?
Off-load – Weekly
On-load - Monthly
c) How can you start an emergency generator?
Manual & Auto – Air, Hand Crank, Batteries
d) How do you test the automatic start on an emergency generator?
Trip the tie breaker from 440V MSB to 440V ESB. This simulates a blackout and the Emerg
Gen will automatically start and connect itself on the board within 45 sec.
e) How long should it take to start after a blackout? 45 Seconds
f) How often should the emergency generator be tested?
Off-load – Weekly
On-load – Monthly
g) What services does the emergency generator supply? SOLAS required equipment?
• Steering Gear
• Emergency Lighting
• Emergency Fire pump
• Fire Detection System
• Elevator
• Communication Systems
h) Where are emergency exit lights and signs powered from?
Internal Battery supplied from EM SWBD
Q4. Propulsion
a) Types of speed control?
Governor, Synchro, Cyclo
b) Differences between types of speed control?
Gov – Controls fuel allowed to generator
Synchro – Fixed Freq AC -> DC -> Controllable Freq AC
Cyclo – Fixed Freq AC -> Controllable Freq AC
c) What are the main types of thrusters on ships? How do they work?
Bow and Stern - CPP
(d) What is pulse width modulation? Why is it converted back into AC? Draw a typical wave
form for PWM.
Pulse Width Modulation (PWM) is a technique used to vary an output voltage. It switches the
waveform on in a series of pulses. To control the power of the waveform it varies (modulates) the
width of these pulses.
e) Explain commutation.
Commutation of a thyristor occurs when the thyristor is turned off. A thyristor can be
naturally commutated using AC when the current goes to zero.
f) What is regenerative braking? What types of drive system can this be used on?
Regenerative breaking occurs when the ships propeller is rotating through the water when the
propulsion system is not powering the PEMs. The rotating rotor induces an EMF in the PEM
and electricity is generated which is back fed into the electrical system.
g) How would you make a PM ready for use? What interlocks might be in place for the PM
breaker to close?
Cooling, Excitation. Interlock –
Power available,
Q5. Motor Starters
a) Draw a typical circuit diagram for
a motor with a direct on line starter.
b) What is the control circuit? What
does it do?
A control circuit is the circuit that
controls which mode the motor
should be in. It has emergency stop,
start and stop buttons which power
on and off the motor. It does this by
controlling the motor contactor coil
in the power circuit.
c) What is the typical starting current for an asynchronous motor with a DOL starter?
This depends on the motor size. Typically a DOL starter has 6 x IN
d) How would you change the direction of a
3 phase motor using components and not
just switching the lines around?
Fwd/Rev Contactor with Interlock (timing)
e) Causes of tripping
Short Circuit – Fuse
Thermal Trip – Thermistor
Overload – O/L Relay
f) What is an OCR?
An Overcurrent Relay is a protection device
that trips if the current in the circuit exceeds
the OCR set current.
g) What is a differential OCR?
Monitors each phase and detects any difference to detect single phasing of a motor.
h) Why doesn’t the OCR trip during starting?
Inverse time curve:
i) What can cause an OCR to fail?
Temperature – Bimetalic Trip
Defective – Needs identical replacement
j) Why is the manual resetting of an OCR important?
Auto reset is only fitted on emergency equip such as Em Fire Pump. If a motor trips it has to
be manually reset.
k) What is the inverse time characteristic?
As Above
l) What is a fuse?
Protection device made of wire that breaks if a current higher than its rated current flows
through it. Trip faster than breaker for short circuit faults.
m) What should the rating of the fuse be?
Correct Voltage level
Correct Current level
n) What fuses should a motor with a running current of 15A and a starting current of 90A
have?
15A x 1.5 = 22.5A with inrush current of 60 sec
o) What is the difference between a fuse and OCR?
A fuse is a short circuit protection that will blow if the current travelling reaches a level too
high. This will need a replacement part for the circuit to operate again.
An OCR is a relay that will trip the circuit if the current reaches a level too high but can be
reset.
p) How can you reduce the starting current of a motor?
Using reduced voltage, slow starting techniques such as Star-Delta starters or autotransformer starting circuits.
q) What is the starting current for a star-delta starter?
If a motor is started in star it takes only 1/3 the starting current than if started in delta.
r) What is the time delay when switching between star and delta?
Depends on motor size, longer than normal running time
A time delay is set on the KM2 aux contacts to create an electrical interlock between KM1
and KM3. This prevents short circuit fault across supply lines when switching from star to
delta.
s) What happens if a motor gets stuck in star configuration?
The motor would overheat and trip on a thermal overload.
t) What happens if all 3 contactors get stuck in?
Short circuit fault across the supply windings.
u) Draw a typical circuit diagram for a star-delta motor starter or an autotransformer motor
starter.
v) What is the starting current for an autotransformer starter with a tapping of 50%?
Half of normal starting current
w) Describe how a soft start starter works.
Use autotransformer with multiple tapping’s to slowly start a circuit to reduce starting current
spike. E.g. 50% tap to 80% tap to 100%
x) What kind of under voltage protection is there in a motor starter?
The contactor protects against under voltage as it only closes when the correct voltage is
present.
y) What are the problems with starting a large motor?
The starting current is very high in large motors. Star-Delta starters are used to overcome the
huge starting current.
z) What are the relationships between star and delta regarding current and voltage?
Star: IL = IPH , VL= √3 x VPH
Delta: IL = √3 x IPH , VL = VPH
aa) When replacing contacts in a starter, how many would you replace and why?
You would replace all contacts, fixed and moving, because the surface would be uneven if you only
changed one and cause hotspots.
Q6. Motors
a) How does a motor work?
3-PH supplies stator winding that crates a moving magnetic field. This induces a current in
the rotor, which tries to catch up with the moving magnetic field of the stator but never will
and will continue to rotate.
b) What planned maintenance is done on a motor?
Visual Inspection – No hotspots, Clear ventilation
Check Contacts – No pitting
Ensure OCR is set at correct setting
Insulation Resistance – Megger
Continuity – Small winding resistance
c) How can you improve the power factor of a motor?
Induction motors are set with a power factor and printed on the label
Synchronous motors can improve power factor by adding additional excitation current
d) What is a synchronous motor?
An AC motor where the shaft is synchronized to the frequency of the supply.
𝑭𝒙𝟔𝟎
𝐹𝑟𝑒𝑞𝑢𝑒𝑛𝑐𝑦 𝑥 60
Here, N = 𝒑
=>
Speed (RPM) = 𝑁𝑜. 𝑝𝑜𝑙𝑒 𝑝𝑎𝑖𝑟𝑠
e) What is an asynchronous motor?
An induction motor, 3-PH supplies stator winding that crates a moving magnetic field. This
induces a current in the rotor, which tries to catch up with the moving magnetic field of the
stator but never will and will continue to rotate.
f) Why would it be beneficial to do an IR test on a motor while the motor is still hot?
The resistance will vary with temperature so while the motor windings are “hot” the results
will be more realistic.
g) How would you overhaul a motor that has been flooded with sea water?
Clean, Dry, Re-Varnish
Clean off salt using fresh water and contact cleaner. Dry windings under lamps or inject
current from a welding set. Re-Varnish windings. Test IR.
h) What would a clamp ammeter read if it was clamped around a 3 core cable connected to a
motor known to be carrying 100A?
0A and it takes the sum of all cables. You need to clamp 1 cable at a time.
i) How could you detect if a motor is single phasing?
Current will increase - Overload
Motor will slow down
It will cause a lot of noise
j) How do you change the bearings on a small motor?
Dismantle motor, mark to ensure closed properly next time
Use bearing puller to remove old bearings
Clean shaft and put light film of oil
Heat up new bearings and place of shaft quickly use a pipe to push as far as possible
Grease to manufacturers requirements
k) How often should an electric motor be cleaned?
Follow manufacturers guidelines and clean for every Planned Maintenance, bearing
replacement.
Q7. Circuit Breakers
a) Which kind of circuit breaker is mainly used on a low voltage switchboard?
MCCB- 1,000A
ACB – 10,000A
b) What kind of maintenance is done on a circuit breaker?
Clean away dust and dirt using compressed air
Clean contacts with fiberglass pen
Clean arc chutes
Test hand crank open and close operation
c) What are the main features of a circuit breaker?
Overload
Short Circuit
d) What is the most important rating on a circuit breaker? Why?
Short Circuit Rating, This is the highest rated current the breaker can handle and the circuit
can provide.
e) What is the main advantage of a circuit breaker over other devices?
It can be reset and a new replacement isn’t needed every time it trips on a fault.
f) A breaker on the switchboard won’t close. What could be the problem?
Solenoid is burnt out. Short circuit is present on the circuit.
Q8. High Voltage
a) Why is high voltage used?
High voltage uses less current. This allows machinery and cables to be smaller which reduces
in costs.
b) Explain how to safely isolate a transformer.
Fill out HV permits to work, switch of the breaker from the primary than secondary
Isolate the breaker from the primary and secondary then lock and tag out
Prove all lines are dead with probe and proving unit
Prove transformer is dead
Apply CME
c) How is earthing achieved on a HV system?
Circuit Main Earth and Additional Earthing Straps.
d) How do you use a HV testing probe to prove a circuit is isolated?
First prove the unit is working using the proving unit (LED flashes)
Test the circuit with clamp to earth and probe to circuit (see if LED flashes)
Prove unit again with proving unit
e) What kinds of circuit breakers are used on a HV system?
SF6 and Vacuum Circuit breakers
f) How do ACB’s dissipate an arc?
The ACB uses Arc Chutes which stretch the arc to quench it.
g) What is a CME?
Circuit Main Earth. This is the earth bond that connects high voltage equipment to earth to
ensure safety.
h) What is a NER?
Neutral Earthing Resistor
i) Why is a NER used?
These are used on high voltage systems to limit the current so it doesn’t damage equipment
but enough current so that protection relays activate to isolate the fault.
j) What is a sanction to test?
A sanction to test is a type of permit used for high voltage equipment. It allows you to
remove the CME to perform an insulation test.
k) What voltage is considered high voltage?
>1000 V
l) What voltage would be used to IR test on a 3.3kV HV system?
5,000 V Megger
m) What is the most common planned maintenance for on a HV system?
Visual Inspections of Generators, Transformers etc.
Motor, Generator Maintenance etc.
n) Why is a HV system not isolated from earth?
So it can automatically trip if a fault occurs such as an earth fault
o) What is the acceptable minimum limit for insulation resistance on a HV system?
Q9. Steering gear
a) What is the steering gear? What does it do?
The steering gear is a system the uses hydraulics to control a rudder to different positions.
The rudder controls the direction the ship travels.
b) Describe the main features on the steering gear.
the rudder is used for diverting the flow of water to turn the ship
the rams or rotary vain are used to move the rudder
the hydraulic pumps are what build up the pressure to the rams
and the control system is what allows the boat to be stared from the bridge, ECR or local control
c) What maintenance is carried out on the ships steering gear?
Motor maintenance, Test & Trips, Feedback pots, Calibrate bridge readings to true
d) What are the 2 main types of steering gear?
Rotary Vane & Hydraulic Ram
e) What are the regulations regarding steering gear?
28 sec for rudder to travel hardover port to 30˚ starboard
f) How would you know if a steering gear motor was single phasing? (Theres no OCR)
Differential Detection – protection against single phasing
g) Where will at least 1 steering gear motor be powered from?
Emergency SWBD
Q10. Batteries
a) What safety precautions should be taken before work is done on a battery?
PPE, Ventilate area, Intrinsically safe equipment
b) What is considered a typical voltage for a fully charged lead acid battery?
27 V on a 24 V battery,
c) What is an acceptable number for the specific gravity for a fully charged lead acid battery?
About 1300
d) What is an acceptable number for the specific gravity for a discharged alkaline battery?
These don’t change, usually about 1200
e) What is an acceptable number for the specific gravity for a charged alkaline battery?
1200
f) Should the specific gravity change for either battery?
Lead-Acid batteries specific gravity will slowly drop as it discharges.
g) What are batteries used to supply on ships?
GMDSS Equip
h) What first aid treatment should you apply if someone is splashed with acid or alkaline
from a battery?
Wash area with water and let acid drip away from casuasty
i) Why should lead acid and alkaline batteries never be stored near eachother?
Alkaline batteries neutralise Lead Acid and make them useless.
j) What are the advantages and disadvantages of using lead acid batteries over alkaline
batteries?
Adv – Cheap, Dis – Maintenance, Shorter Life Cycle
Q11. Transformers
a) What do transformers do?
Transformers take in a voltage of one level (440V) and outputs another level (220V)
b) What kind of maintenance is done on a transformer?
Clean and tighten the contacts and the exterior of the transformers
Check the resistance of the coils (small resistance (0.1Ω)
Check the insulation resistance of the transformer
c) What precautions should be taken when isolating a transformer to do carry out
maintenance on?
Isolate primary and secondary of transformer lock and tag out breakers. Prove dead.
Any instrumentation or thermistors should be disconnected
d) What is an isolating transformer?
An isolation transformer is a transformer that takes in one voltage and gives out the same
voltage (1:1). This is used to stop feedback through the system e.g. Earth Faults. This is
commonly found on galley equipment.
e) How would you IR test a transformer?
Winding to Winding then Winding to Earth
Q12. Bridge Equipment
a) What is an ECDIS?
Electronic Chart Display and Information System. It shows the info from the nav charts on a digital
computer display. AIS, GPS, Radar and gyro will be inputs, along with heading and autopilot course
and track
b) What is an SVDR? What information is fed into an SVDR?
Simplified Voyage Data Recorder
This will have inputs from: GPS position, Speed log, Gyro, Audio on bridge, VHF
communications.
c) The SVDR is in alarm while the ship is in port. What could be the problem?
No input from Radar due to system shutdown in port.
d) What is a radar? How does it work?
Radar is a system that uses high frequency radio waves (3Ghz or 9Ghz) to detect echos from solid
objects. The radio waves bounce off the object. The feedback wave (echo) is then fed into and
amplified by the receiver and displayed on a screen on the bridge.
e) What should happen to bridge equipment during a blackout?
Equipment fitted with UPS stay powered always other should be supplied by emergency
switchboard after 45 sec
f) What is a Doppler log? How does it work?
This measures the speed that the ship is travelling. It uses the Doppler effect by transmitting a
frequency and the motion of the ship causes a shift in frequency.
g) What is an echo sounder?
The echo sounder fires a ultra-sonic wave downward which will then bounce off the bottom of the
ocean be received back at the ship .
The time taken for this to occur will then be calculated to give an accurate idea of the depth below
the keel.
h) The echo sounder is on in port but nothing happens, what could be the problem?
There may not be enough water under the ships keel to detect.
i) What tests would you do on a GMDSS?
Daily – VHF internal test, MF/HF Internal test, Batteries charged
Weekly – MF/HF test call, VHF DSC bridge to bridge
Monthly – Test EPIRB, SART, Portable VHF, batteries on-load.
j) Draw a typical circuit for navigation lights. How would you know if there is a fault?
k) What is autopilot? How does it work?
This is a system the controls the direction of the ship with out an operators hand control. It
works by setting a heading e.g. 270˚ the gyro compass detects true north and the ship will
stay on this heading within settings until it is altered.
l) What equipment is required to work in order for a ship to sail?
Gyro, GPS, Radar, Steering, VHF, Mag. Compass,
m) What is AIS? Should it be switched off in port?
Automatic Identification System. This uses VHF to show a position of the ship traffic in your
vicinity. No, unless the ship is in a high security piracy area and the master wants it to be
switched off.
n) What are NUC lights and where are they powered from?
Not under Command.
Q13. Fire Fighting and Fire Safety
a) What fixed installations can be used on a ship?
Co2, Hi-fog systems, Sprinkler
b) What type(s) of extinguisher can be used on an electrical fire?
Co2 & Dry Powder
c) What type(s) of extinguisher can be used on a fuel oil fire?
Foam
d) How do you use a water fire extinguisher?
Remove safety pin, spray towards floor to ensure operation, Position your self low and aim at
base of the fire.
e) What precautions should be taken when using CO ?
Extinguishers – Don’t grip nozzle at it gets very cold, don’t use in a confined area
Co2 system – Ensure area is evacuated, do a full head count. Close ventatation. Chief
Engineer and Captain can say to operate the Co2 system.
2
f) Who is in charge of the operation of the ships CO system?
Chief Engineer with the Captains consent.
2
g) What is the ETO’s role in a fire onboard a ship?
Tanker: Control Room to isolate any equipment.
Cruise: SETO is on the first stage response
1st ETO is present in the control room
2nd ETO can be in charge of boundary cooling
3rd ETO can be part of the fire team or as an extra man in the ECR
h) What kinds of fire detector heads are used and how are they tested?
Heat detector. Heads tested using a digital heating rod
Optical smoke detectors can be tested use test smoke canister
Flame fire detectors can be tested using UV light
i) What kinds of detection components are used other than smoke, heat and flame detectors?
Manual Call point
j) How often should the fire detection system be tested?
Tests are carried out weekly and the entire ship is tested every three months on tankers. It
usually takes cruise ships 1 year to complete the entire ship.
k) You find a fire in the galley. Go through the procedures of what you would be expected to
do in this event?
Sound the MCP alarm calling FIRE, FIRE, FIRE! Evacuate the area.
If the fire is small, attempt to extinguish using a portable extinguisher
If fire is large, confine area and contact bridge about type of fire.
Muster and follow your duties. ETO usually isolates all galley equipment from main
switchboard.
l) What tests should be carried out on a BA set before using it?
BA Donning Procedure:
• Turn cylinder valve on fully take note of pressure, wait 1 minute and if
pressure dropped by >10Bar that air bottle can’t be used. [High pressure test]
• Ensure cylinder valve is off.
• Ensure demand valve is correctly fitted to the facemask.
• Check lung demand valve (LDV) is closed, depress first breath mechanism.
• Turn cylinder valve on fully and listen for any leaks.
• Check cylinder pressure (min. = 240 bar).
“On Air” Procedure:
• Fit facemask, adjust head harness buckles.
• Exhale breath then inhale sharply to initiate first breath mechanism.
• Insert 2 fingers between your face and the mask, should be an outflow of air
indicating that the set is operating in positive pressure.
• Take 2 or 3 breaths then hold breath for 5 seconds. There should be no
audible flow.
• Ensure the manual operation of supplementary air is working by holding in
the LDV
• Hold breath and turn off the cylinder keeping your hand on the cylinder valve.
• Breathe the set down slowly observing the gauge and noting the activation of
the whistle (about 50-60 bar). [Low pressure test]
• If any leaks are identified re-fit the facemask and re-test.
• Fit fire hood and helmet.
• Check the gauge reading is still ok.
After use:
• Take a breath, reset first breath mechanism.
• Loosen head harness buckles, bottom, middle, and top.
• Remove facemask.
• Depress cylinder valve ratchet and turn valve off.
• Take off apparatus and lay it on its back plate on the deck.
• Drain the remaining air using the bypass valve.
• Fit fully charged air cylinder and check pressure (min. = 240 bar)
• Re-stow equipment in ready to use condition
m) What are the main causes of engine room fires?
Oily rags, bad house keeping
n) What pumps can be used to supply water to the fire main?
Fire pumps, Em. Fire pump, General service pump
o) Where are the fire pumps supplied?
Emergency fire pump has it own starting system (batteries and diesel) & Emergency SWBD.
p) Where would you usually find the emergency fire pump?
Trader – Fo’c’sle
Emerald – Steering Gear Room
Q14. Lifesaving apparatus
a) How much water ration per person is in a lifeboat?
3 liters
b) What kinds of flares are there on a lifeboat and how many of each?
2 – Smoke flares
4 – parachute flares
6 – hand flares
c) What is a sea anchor and what is it used for?
A cone shaped cloth. Used for stabilizing the lifeboat, reduces drift
d) What is a TEMPSC?
Totally Enclosed Motor Propelled Survival Craft
e) What is the maximum time it should take to launch a fast rescue craft?
5 minutes
f) What checks should take place before entering and lowering a lifeboat?
Harbour pins in while personnel are in checking the lifeboat.
Ensure engine is running with enough oil, steering is ok, FPD is fitted,
Ensure charging plug is disconnected and area below boat is clear.
Now remove harbor pins and lower.
g) What would you do if you heard 3 short blasts and 1 long blast on the ships whistle?
Muster
h) What would you do if you heard 7 short blasts and 1 long blast on the ships whistle?
7 Short 1 long = Abandon Ship, Captain gives verbal order.
Q15. First aid
a) What kind of injuries could arise from electricity?
electrocution (fatal),
electric shock,
burns
b) How would you treat someone having a heart attack?
Place in a upright sitting position with knees bent, circulates blood to heart
Call the medic. State that you suspect a heart attack
Constantly monitor casualty
Reassure.
Never leave the person alone in case that person goes into cardiac arrest and you need to
defibrillate
c) How do you control bleeding?
Sit casualty down. Apply pressure to the wound and elevate. Dress the wound and suppost
the injury.
d) What is the first thing you should do if you find an unconscious casualty?
Ensure airway is open
Call for help
Look for evidence why they are unconscious
Q16. Hazardous Areas
a) What does “intrinsically safe” mean?
Intrinsically safe means the equipment is limited to a power so it cannot cause an explosion in
a gas air environment.
b) What is a hazardous area?
A hazardous area in an area where a gas air mixture might be found.
c) A piece of equipment has “EEx d IIC T6” written on it. What do these figures mean?
x d
Ex i
Ex e
Ex n
Ex q
Ex o
Ex p
Flame proof
Intrinsically safe
Increased safety
Non-sparking
Powder filled
Oil immersed
Pressurization


C
Methane
Amonia, Acetone, Propane, Butane,
Ethenol
Ethylene, Diethylether
Hydrogen
T1
T2
T3
T4
T5
T6
450°C
300˚C
200˚C
135˚C
100˚C
85˚C

d) What are zones?
•
•
•
Zone 0 – Gas-Air mixture constantly present
Zone 1 – Gas-Air mixture is likely to be present
Zone 2 – Gas-Air mixture is not likely to be present
e) What do the temperature groups mean?
It means the maximum temperature the exterior casing can reach under fault conditions.
f) What kind of hazardous area equipment would you expect to find in use in a paint store?
Zone 1, Ex d lighting.
Q17. Boilers
a) What types of sensors would you expect on a boiler?
Steam Temperature, Steam Pressure
b) What safety devices would you expect to find on a boiler?
Safety valves to release over pressure.
Q18. Refridgeration and AC
a) Name the electrical components usually found in a refrigeration or AC system.
Compressor motor to pressurise the vaporised refrigerant
Fan motors
Solenoids for opening and closing the refrigerant line
b) What is a compressor?
A compressor is a machine that pressurizes a gas or air in a tank. For refrigeration, the
compressed gas goes to the condenser then passes through the expansion valve into the
evaporator.
c) If a compressor is switching on and off – is it fair to think the problem is the motor itself?
What else could be the problem?
The supply might be faulty
Thermostat could be faulty
Damper could be faulty
d) What could be happening to the motor from constantly switching on and off?
Overheat and burn the contacts. Compressor may also be damaged from overworking.
e) If the contactor is stuck closed, what could this cause?
Contacts have welded together - isolate supply, prove dead, replace contactor.
f) Why would a compressor run hot?
Fan could be blocked
Q19. Miscellaneous Electrical
a) What is a short circuit fault? How do you test for this?
When two conductors in a circuit are touch together giving a resistance of zero. It can be tested by
checking the resistance between points on the circuit. A short circuit will read as 0Ω
b) What is an open circuit fault? How do you test for this?
When a part of a circuit that is usually connected becomes disconnected. This can be tested
by measuring the resistance a very high resistance or open line will be read.
c) How would you safely isolate a piece of equipment? e.g. a Transformer
Open circuit breaker on primary then secondary
Remove any fuses
Prove circuit is dead
d) What is a live line tester?
A voltage testing unit which has insulated probes and is tested before and after use.
e) What is a UPS? What does it do?
Uninterruptable Power Supply. This is a unit which is normally powered by mains power but in the
event of loss of mains, the battery will instantaneously power the load.
Connected to critical load that will automatically switch over to battery power in event of power cut.
f) What services rely on UPS systems?
Computer systems, Navigation Equipment, HV breaker instrumentation
g) What is a diode?
A semiconductor device that conducts in one direction when 0.7 V is present across it
h) What is a transistor?
A switching device that switches on when 0.7V is present between the base and emitter.
i) What is a thyristor?
A switching device that closes when the gate is pulsed. Used on electric propulsion systems
where the thyristor can be pulsed at different firing angles to vary the frequency. Naturally
commutated when the AC current goes through zero.
j) What is a PI index?
A PI index is a method of determining the health of a HV motor. It is much more accurate than an IR
test alone the PI test takes the IR at 1 minute, and then over a further 10mins. The result is a ratio of
the two readings between 10:1. Readings of >5 is very good. 2 is acceptable, but your looking for
readings above 4, or the motor should be replaced in the near future.
Results recorded over time for best results
k) What is IR testing? What voltages should be used?
Insulation Resistance test (Megger). This tests the insulation resistance of the windings of a
motor to ensure there is no leakage to earth or connection between 2 windings.
l) How does an IR tester work?
The IR tester sends a high DC voltage through 2 windings if there is a connection the
resistance will be low. The ideal reading ∞MΩ.
m) Where are earth faults most likely to occur?
Deck equipment that is exposed to harsh atmospheres.
n) In what circumstances is working on live equipment permitted?
Never
o) How can you test a fuse?
Measure continuity
p) How does a fluorescent light work?
The starter supplies a high voltage across the fluorescent tube which heats up the tube and
moves the electrons. When the starter opens the ballash magnetic field collapses and a surge
strikes the lamp.
q) What would you expect was wrong if a fluorescent light kept flashing when it was
switched on?
The starter needs replacement.
The lamp is faulty
r) What is the capacitor for in a fluorescent light circuit?
Power Factor Correction
s) What happens if you remove the starter from a fluorescent light while it is lit?
It will stay lit but if it is turned off it will not light.
t) Do ammeters on the MSWB panel and on starter panels carry full load currents? How?
No, these use current transformers that use a ratio of the current to show the current flowing.
u) What is a current transformer?
Current transformers step down the current by a ratio to make it safe for instrumentation use.
v) What is low location lighting?
This is emergency lighting that illuminates in emergencies to show the route of escape to a
safe place.
w) What types of sensors would you expect to find around the ship?
Flow, Temp, Depth, Pressure
x) How do you test these?
Controlled compressed Air, Controlled heater, Controlled Depth, Controlled compressed air
y) What is the alarm system? What does it do? How does it work?
General alarm – Continuous 2 tone (Fire)
Boat Muster – 7 Short, 1 Long
Q20. Miscellaneous
a) What is cathodic protection?
Cathodic protection is a system which prevents corrosion to the hull. This is achieved by fitting
sacrificial anodes to be corroded instead.
ICCP is another form of cathodic protection. Ship is a cathode, Anodes are fitted to ship. DC current
is supplied which simulates the anode being corroded.
b) What is a watertight door? Explain how a watertight door is safely operated. Where can
they be operated from?
Hydraulically operated doors that don’t allow water to be passed through them and confine
the ship into watertight compartments. Push lever to open position, when door is open push
lever on the other side of the door to the open position and pass through.
These can be operated locally and remotely from the bridge.
c) What is a permit to work? When should they be used?
PTW is a document listing all the hazards and measures in place to overcome these hazards
associated with a job.
It will list people involved, risk assessment, reviewed and work to be done.
E.g. Working aloft, all safety precautions need to be followed like getting harness and notifying
relevant people.
d) What should be done prior to obtaining a permit to work?
Assess all safety factors needed.
Carry out risk assessment.
Also consult with your trusted senior colleagues.
Work should not be carried out unless you feel safe and confident.
Prepare any drawings needed to show where isolations will be fit.
e) What permit might you need for working up the ships mast? What safety equipment would
you use?
Working aloft
Safety harness
VHF radio
Standby man
f) What precautions should be taken before doing work in an enclosed space?
Area is sufficiently ventilated.
Area is tested to have 21% oxygen
Risk assessment and PTW completed.
Standby team with BA and rescue equipment
g) How would you control an oil spill?
Raise alarm, Contact Bridge. Isolate supply. Confine Area. Start cleaning process with
pumps, mops, rags. Inform emergency services.
h) What is an oily water separator?
An oil water separator (OWS) is a machine that separates oil and water mixtures into their separate
components. They are used to separate oil from oily waste water, such as bilge water, before the
waste water is discharged into the environment.
Modern OWS’s have alarms and automatic closure devices which are activated when the oil storage
capacity of the oil water separator has been reached.
i) What is lifting gear? How is it rated? How is it tested? What is the colour coding scheme?
Lifting gear is any equipment that is used for lifting or lowering loads.
Equipment is sent ashore to be tested annually and new equipment is supplied to the ship.
The color code scheme used onboard ships sets a certain color for the SWL (Safe Working
Load) of that equipment. A reference chart is posted at the areas where lifting equipment is
stored.
j) Chief engineer tells you to do work on a lift and you don’t have a permit to work. What do
you do?
You are responsible for your own safety. Don’t attempt to carry out unsafe work without a
permit. If an accident happens you will not be insured and the chief engineer will take no
responsibility.
Q21. Regulations