Marine Propulsion History and Electric Propulsion & Future Technology
1. Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh.
Marine Propulsion History
And
Electric Propulsion &
Future Technology
1
2. 40,000 years before christ, man built boats and
paddled through the waters with them. And, they
paddled and paddled and paddled for 35,000
years until a major discovery revolutionised ship
propulsion for the first time.
History of Marine Propulsion
5/17/2014 2
Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
3. Mankind paddled round for 35,000 years – just like the
indians – and then they began using oars –similar to the
tourists on the alster lake.
Then mankind oared round for several thousand years
– namely, up to 3,000 b.c. until the sail was discovered,
supposedly in Egypt. finally, more than just the nile and
the coastal regions of the Red and Mediterranean seas
could be explored. the seafarers could then set off on
voyages crossing the seas and circling the continents.
For a long time, the seaman couldn’t give up using the
oar and combined the oar with the sail.
History of Marine Propulsion
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
4. The ships got bigger and bigger, Hamurabi lived and died,
and, finally, the oars were completely done away with. And,
in this manner, mankind sailed almost 5,000 years – until
the year 1770 A.D.
Roman warship with sail and oars – around 200 B.C.
History of Marine Propulsion
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
5. when James Watt, further developed the steam engine so
that it, a short time thereafter, could be built into a ship.
History of Marine Propulsion
Cross-section and full-view of a 2-stage steam engine5/17/2014 5
Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
6. At this period in time, the propeller had not yet
been invented and, what was more convenient to
make use of than the old-familiar paddle-wheel of
the flour and lum- ber mills.
The paddle-wheel propelled the ship, and the
steam engine drove the paddle-wheel. The coal-
fired boilers provided the steam for the steam
engine.
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
7. “Contemporary” depiction of propulsion (steam engine and
paddle-wheel) of the steamboat "Claremont"
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
8. There were certainly attempts at in- terim solutions. This
illustration is not a comic drawing but rather the then
contemporary depiction of a submarine propelled by
muscle power, which sank the "Housatonic" in 1864.
Submarine "H.L. Hunley" on 17.02.1864 while attacking the
"Housatonic"5/17/2014 8
Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
9. Mankind didn’t throw the sail overboard and install a steam
engine, rather one slowly felt his way forward – the ships
had a sail and a steam engine and a paddle-wheel (later a
propeller, as well).
Steamship "Great Eastern" around 1860. The ship had 6 masts, 2
paddle-wheels and a four-bladed propeller5/17/2014 9
Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
10. Steamship "Helena Sloman" around 1850. The ship had a full
set of sails and a propeller5/17/2014 10
Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
11. Then, 60 years later, in the year 1827, Joseph Ressel had
the ship propeller patented. He was an Austrian and had
the exciting title of a “Marineforstintendant”.
The iron propeller was a great improvement as compared
with the wooden paddle-wheel with its many fragile pieces.
The propeller was able to be adapted to all of the following
types of propulsion and output standards of today.
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
12. Depictions of a paddle-wheel and a “prototype” of a propellerr
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
13. Meanwhile, propellers are built which can manage 120,000
hp and weigh over 130 tonnes having a diameter of just
short of 10 metres. Here, the limit of possibility certainly
seems to have been reached.
5-bladed control pitch propeller for a container
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
14. Let’s take just another look back into the century before the
last, in which the steam engine set about replacing the sail.
The demands made on output got bigger and bigger; the
steam engines, as well. The performance limit of 20,000 hp
per steam engine was quickly reached. So, several steam
engines had to be built into a ship in addition to numerous
boilers – sometimes 15 or more. Besides that, many
hundreds of tonnes of coal had to be brought on board and
stored.
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
15. One of the two steam engines of the steamship
"Kronprinzessin Cecilie" (1907), 22.000 hpi
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
16. Around 1900, the first steam turbines were built into
ships. While having a larger output, they required
much less space than steam engines, but the old
steam boilers remained on board, and they were still
fired manually with coal.
Cross-section of a high-pressure stage of a modern steam turbine
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
17. The amount of effort required to fire the boilers with coal is
no longer imaginable today! One needed the coal heaver,
who transported the coal from the storage room – from the
coal bunker – up to just in front of the boiler; one needed
the stoker, who shovelled the coal into the boilers and
maintained the steam pressure; one needed the many
helpers, who transported the ash from the boiler overboard.
And, all of that for each individual boiler and for each of the
three shifts.
View of the boiler room of a coal-fired steam boiler system5/17/2014 17
Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
18. Around 1920, when the Hamburg-Süd steamship "Cap
Polonio" was refitted from coal-firing to oil-firing, the boiler
room personnel was able to be reduced by just 110 men.
View of the furnace of two oil-fired steam boiler systems5/17/2014 18
Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
19. With the steam turbines, finally the industry had ship propulsion
systems with - for ship standards – huge performance reserves
available (today, stationary steam turbine systems are built with
over 1.5 million horsepower per turbine). The oil-fired boilers were
also quite comfortable.
But, in this case, fuel consumption was very high. The efficiency of
a steam turbine was, in comparison with a steam engine, from
which only 10 to 20% of the energy used made it to the propeller,
considerably better – but still left loads of room for improvement
having only 25 or 30% efficiency.
So, in regard to ship propulsion, the steam engine and the steam
turbine only had a relatively short “cameo-appearance” in the
greater scheme of things.
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
20. In the year 1876, thus 130 years ago – the combustion
engine was invented by Nikolaus Otto. It had to be driven
with benzine, which at the time had to be purchased at the
chemist’s with high prices.
The combustion engine was, thus, discovered, but it wasn’t
originally good for ship propulsion because it used too
much expensive petrol.
Even 50 years before the invention of the Otto motor, the
Frenchman, Carnot, described a thermo-dynamic cyclic
process with theoretically the highest possible degree of
efficiency.
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
21. With the above in mind, Rudolf Diesel developed a combustion
engine which operated according to the Carnot-principle and had
the same patented in 1892. The 'diesel engine' reached a
spectacularly high efficiency of 20, then 30, then 40 and finally
45 %.
Around 1910, one began to build diesel motors into ships as the
main source of propulsion. The entire diesel engine took up
approx. as much as three boilers and, thereby, replaced a steam
propulsion system, which perhaps was comprised of 2 turbines,
15 boilers and countless auxiliary units and, thereby, required 30
% less fuel.
From 1910 to today, the diesel engine has gone through an
unparalleled technical develop-ment. Similar to the propeller, the
diesel engine was able to be adapted to every demand on size
and output performance.5/17/2014 21
Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
22. Left: View of a large two-stroke diesel engine around 1912
(1,500 hp at 120 RPM)
Right: Embedding of a crankshaft in a 12,000 hp
6-cylinder MAN two-stroke engine5/17/2014 22
Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
23. Ship diesel engines of today are available in every size and
output class up to 135,000 hp. They are extremely reliable, and
the so- called specific fuel consumption is unbeatably low with
119 grams per hp and hour (g/hph) – at its time, the steam
engine consumed approx. 700 g/hph.
In addition, the 'combined heat and power' principle, which is
talked about so often today, has been common practice in ships
with diesel propulsion for ages. Heat is detracted from the diesel
engine’s exhaust gases, which, in spite of everything else, still
contain about 50 % of the thermal energy used, by connected
turbo chargers and steam boilers so that the efficiency of the
entire system rises to over 70 %.
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
24. Cross-section of a MAN-B&W ship diesel engine 6S 70 ME-C (25.000 kW
@ 91 RPM , weight - 550 t, height – 14 m)
The diesel engine has
many advantages. It has
displaced every other
type of propulsion in
shipping. Today, approx.
90% of all merchant
vessels are propelled by
diesel engines, world-
wide.
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
25. However, the times of rapid technical developments in the
ship diesel engine are gone – which, for one, lies in the fact
that the highest possible degree of efficiency has almost
been reached, and, for another, that now possible output of
150,000 hp can no longer be surmounted by one single
propeller. There is no longer any reason to boost the output
of any one single ship diesel engine. In case it’s necessary
– now, two engines would have to power two propellers -
and then there would be 300,000 hp of installed propulsion
output. The size of merchant vessels which would require
such an amount of output are not imaginable today, and
such vessels won’t be playing a roll in shipping in the
intermediate-term.
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
26. The diesel engine has almost displaced every other type of
propulsion and is absolutely market dominating.
It displaced the steam turbine, which today only plays a
secondary role in regard to ship pro- pulsion.
It displaced the nuclear powered merchant vessels which
were built in the 60’s of the previous century – namely, the
Savannah (USA), the Otto Hahn (Germany) and the Mutsu
(Japan).
NS "Otto Hahn" - 1965
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
27. All three ships were powered by propellers, which, in turn,
were driven by steam turbines typical of merchant ships –
only that the steam was not produced in oil-fired boilers but
rather in a so called pressurised-water reactor.
The ships were extremely expensive and uneconomical,
and at their time they were only able to touch at very few
ports worldwide owing to a lacking acceptance in the
population. They also required a large number of well-
trained crew members. The "Otto Hahn" had e.g. a regular
crew of nearly 60 men plus 35 scientists on board.
View of the pressurised-water
reactor of the NS "Otto Hahn"
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
28. The diesel engine also displaced ships with gas turbine
propulsion. These ships had airplane jet engines, which
functioned as so-called gas generators which, in turn, powered
turbines. The latter rotated similar to a steam turbine and
powered our old-familiar propeller.
Pratt & Whitney gas turbine FT 4 A12 (30.000 Ps) of the GTS "Asia Liner"
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
29. Even this type of propulsion was extremely uneconomical
in that it, for one, required the same top-quality, expensive
fuel as that of an airplane jet engine and on top of that, it
had an effi- ciency of only 21 % which was – at least in
comparison to that of a diesel engine – awfully low. Every
ship with gas turbine propulsion known to me was
converted to diesel engine propulsion after a few years.
In the table below, we can compare the degrees of
efficiency and specific fuel consumption of the various
types of propulsion. The specific fuel consumption is, by the
way, the amount of fuel that the system must be given in
order to produce 1 hp for one hour (g/hph). we see that the
modern Engine Makers have worked down from 700 g/hph
to 120 g/hph today.
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
30. Comparison of the thermal degrees of efficiency and specific fuel
consumption
efficiency specific fuel
consumption
sail ./. 0
steam engine 10 – 15 % 700 g/hph
gas turbine 21 % 320 g/hph
steam turbine 30 % 220 g/hph
diesel engine 45 % 120 g/hph
hydrogen 30 % ./.
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
31. The ship propulsion must be reliable and, above all, economical.
Diesel propulsion satisfies both requirements thoroughly and
without any competition – at least as long as heavy fuel or diesel
oil or, as the case may be, liquid gas (LNG) is readily available
and affordable.
Beginning in 2070, oil appears – in comparison to today – to play
a rather inferior role. In other words, there is little to be said
against the diesel engine’s maintaining its dominating role in the
market at least until 2030.
the SKYSAIL or the FLETTNER-ROTOR don’t really help us out
of the predicament, either. Our ships need propulsion
independent of the weather and with enormously large output.
"Auxiliary propulsion units" cannot manage this by far.
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
32. SkySail – only suitable for „auxiliary propulsion“
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
33. Flettner-Rotors – only suitable for
„auxiliary propulsion“5/17/2014 33
Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
34. Special ships such as submarines – is hydrogen
propulsion. The term "hydrogen propulsion" is just as
misleading as "nuclear propulsion". A ship with hydrogen
propulsion is still powered by the propeller and the latter by
an electric motor. Both components are old friends – the
propeller, anyhow, and the electric motor has already been
implemented in the so-called diesel- electric propulsion for
many years. Thereby, a diesel engine powers an electric
generator of which energy goes to an electric motor, which,
in turn, powers the propeller. The last step of this
development is the so called 'AZIPOD', which contains the
electric motor directly in the pod (gondola) behind the
propeller.
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
35. “Electric 'Azipod' propulsion”
Left: View of the 'gondolas' with drag-propeller
Right: Schematic diagram with view of the mounted electric engine in the
'gondola'
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
36. In regard to hydrogen propulsion, we can manage
without a diesel engine and a generator as we
produce the energy for the electric engine e.g.
from the fusion of hydrogen and oxygen, whereby
water and heat are generated so to speak as by-
products – in addition to the energy, itself. In
Hamburg, some buses are already powered by
hydrogen cells, and THYSSEN KRUPP has been
successfully building submarines using this
technology.
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
37. Left: Functional principle of a hydrogen cell
Right: Technical layout of a hydrogen cell for submarines
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
38. To introduce solar energy to the ship we need to convert the
solar energy to electrical energy. electrical energy we can
use and transport throughout the ship. photo-voltaic cells
convert solar into electrical energy. An inverter is needed to
convert the direct current (dc) to an alternating current (ac),
so the 50 or 60 hz electric grid can transport the electrical
energy through the ship. These energy conversions reduce
the efficiency of the whole chain.
With a dc grid in a diesel-electric propulsion system less
energy conversions are needed, There is no need for bulky
transformers.
WIND & SOLAR ENERGY FOR SHIP
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
39. Sail and solar power ship
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
41. Marine Electric Propulsion
Integrated electric propulsion (IEP) or full electric
propulsion (FEP) or integrated full electric propulsion
(IFEP) is an arrangement of marine propulsion systems
such that gas turbines or diesel generators or both
generate three phase electricity which is then used to
power electric motors turning either propellers.
It is a modification of the combined diesel-electric and gas
propulsion system for ships which eliminates the need for
clutches and reduces or eliminates the need for gearboxes
by using electrical transmission rather than mechanical
transmission of energy.
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
43. Marine Electric Propulsion System
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
44. Marine Electric Propulsion
• Electric propulsion for many new ships is now re-
established as the popular choice where the motor
thrust is governed by electronic switching under
computer control.
• The high power required for electric propulsion
usually demands a high voltage (HV) power plant
with its associated safety and testing procedures.
• Passenger ships have always been the largest
commercial vessels with electric propulsion and, by
their nature, the most glamorous. This should not,
however, obscure the fact that a very wide variety of
vessels have been, and are, built with electric
propulsion.5/17/2014 44
Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
45. Marine Electric Propulsion
• Early large passenger vessels employed the
turboelectric system which involves the use of
variable speed, and therefore variable
frequency, turbo-generator sets for the supply of
electric power to the propulsion motors directly
coupled to the propeller shafts. Hence, the
generator/motor system was acting as a speed
reducing transmission system. Electric power for
auxiliary ship services required the use of
separate constant frequency generator sets.
• A system that has generating sets which can be
used to provide power to both the propulsion
system and ship. …..(cont’d)5/17/2014 45
Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
46. • Marine Electric Propulsion
• services has obvious advantages, but this would
have to be a fixed voltage and frequency system
to satisfy the requirements of the ship service
loads. The provision of high power variable
speed drives from a fixed voltage and frequency
supply has always presented problems. Also,
when the required propulsion power was beyond
the capacity of a single d.c. motor there was the
complication of multiple motors per shaft.
…….(cont’d)
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
47. A Typical Layout HV Propulsion System
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
48. Marine Electric Propulsion
• Developments in high power static converter
equipment have presented a very convenient
means of providing variable speed a.c. and d.c.
drives at the largest ratings likely to be required
in a / marine propulsion system.
• The electric propulsion of ships requires electric
motors to drive the propellers and generator sets
to supply the electric power. It may seem rather
illogical to use electric generators, switchgear
and motors between the prime-movers (e.g.
diesel engines) and propeller when a gearbox or
length of shaft could be all that is required.
…………..(cont’d)
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
49. Marine Electric Propulsion
• There are obviously sound reasons why, for
some installations, it is possible to justify the
complication of electric propulsion:
1. Flexibility of layout
2. Load diversity between ship service load and
propulsion
3. Economical part-load running
4. Ease of control
5. Low noise and vibration characteristics
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
50. FLEXIBILITY OF LAYOUT
•The advantage of an electric transmission is that the prime-
movers, and their generators, are not constrained to have any
particular relationship with the load as a cable run is a very
versatile transmission medium. In a ship propulsion system it is
possible to mount the diesel engines, gas turbines etc., in
locations best suited for them and their associated services, so
they can be remote from the propeller shaft. Diesel generator sets
in containers located on the vessel main deck have been used to
provide propulsion power and some other vessels have had a 10
MW generator for ship propulsion duty mounted in a block at the
stern of the vessel above the ro-ro deck.
–Another example of the flexibility provided by an electric
propulsion system is in a semi-submersible, with the generators
on the main deck and the propulsion motors in the pontoons at
the bottom of the support legs.
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
51. LOAD DIVERSITY
• Certain types of vessels have a requirement for
substantial amounts of electric power for ship
services when the demands of the propulsion
system are low. Tankers are one instance of this
situation and any vessel with a substantial cargo
discharging load also qualifies. Passenger
vessels have a substantial electrical load which,
although relatively constant, does involve a
significant size of generator plant. There are
advantages in having a single central power
generation facility which can service the
propulsion and all other ship loads as required.
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
52. ECONOMICAL PART-LOAD RUNNING
•Again this is a concept that is best achieved when there is a central
power generation system feeding propulsion and ship services, with
passenger vessels being a good example.
•It is likely that a typical installation would have between 4-8 diesel
generator sets and with parallel operation of all the sets it becomes
very easy to match the available generating capacity to the load
demand. In a four engine installation for example, increasing the
number of sets in operation from two that are fully loaded to three
partially loaded will result in the three sets operating at a 67% load
factor which is not ideal but also not a serious operating condition, It
is not necessary to operate generating sets at part-load to provide
the spare capacity to be able to cater for the sudden loss of a set,
because propulsion load reduction may be available
instantaneously, and in most vessels a short time reduction in
propulsion power does not constitute a hazard.
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
53. • The propulsion regulator will continuously
monitor the present generator capability and any
generator overload will immediately result in
controlled power limitation to the propulsion
motors. During manoeuvring, propulsion power
requirements are below system capacity and
failure of one generator is not likely to present a
hazardous situation.
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
54. EASE OF CONTROL
•The widespread use of controllable pitch
propellers (cpp) has meant that the control
facilities that were so readily available with electric
drives are no longer able to command the same
premium. Electric drives are capable of the most
exacting demands with regard to dynamic
performance which, in general, exceed by a very
wide margin anything that is required of a ship
propulsion system.
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
55. LOW NOISE
•An electric motor is able to provide a drive with
very low vibration characteristics and this is of
importance in warships, oceanographic survey
vessels and cruise ships where,/-for different
reasons, a low noise signature is required. With
warships and survey vessels it is noise into the
water which is the critical factor whilst with cruise
ships it is structure borne noise and vibration to the
passenger spaces that has to be minimised.
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
56. • For very high power, the most favoured option is
to use a pair of high efficiency, high voltage a.c.
synchronous motors with fixed pitch propellers
(FPP) driven at variable speed by frequency
control from electronic converters. A few
installations have the combination of controllable
pitch propellers (CPP) and a variable speed motor.
Low/medium power propulsion (1-5 MW) may be
delivered by a.c. induction motors with variable
frequency converters or by d.c. motors with
variable voltage converters.
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
57. • The prime-movers are conventionally constant speed
diesel engines driving a.c. generators to give a fixed
output frequency. Gas turbine driven prime- movers for
the generators are likely to challenge the diesel option in
the future.
• Conventionally, the propeller drive shaft is directly
driven from the propulsion electric motor (PEM) from
inside the ship. From experience obtained from smaller
external drives, notably from ice-breakers, some very
large propulsion motors are being fitted within rotating
pods mounted outside of the ship’s hull. These are
generally referred to as azipods , as the whole pod unit
can be rotated through 360° to apply the thrust in any
horizontal direction, i.e. in azimuth. This means that a
conventional steering plate and stern side-thrusters are
not required.
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
58. • Ship manoeuvrability is significantly enhanced by
using azipods and the external propulsion unit
releases some internal space for more
cargo/passengers while further reducing hull
vibration.
•Gradual progress in the science and application
of superconductivity suggests that future
generators and motors could be super-cooled to
extremely low temperatures to cause electrical
resistance to become zero.
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
59. •Integrated electric-drive system derived from a commercially
available system that has been installed on ships such as
cruise ships requires a technology that is more torque-dense
(i.e., more power-dense) .
•Candidates for a more torque-dense technology include a
permanent magnet motor (PMM) and a high-temperature
superconducting (HTS) synchronous motor.
•In addition, electric drive makes possible the use of
new propeller/stern configurations, such as a podded
propulsion ... that can reduce ship fuel consumption
further due to their improved hydrodynamic efficiency
Marine Electric Propulsion
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
60. Marine Electric Propulsion
- Podded drives offer greater propulsion efficiency
and increased space within the hull by moving the
propulsion motor outside the ships hull and
placing it in a pod suspended underneath the hull.
- Podded drives are also capable of azimuth
improving ship maneuverability. Indeed, podded
drives have been widely adopted by the cruise
ship community for these reasons.
- The motors being manufactured now are as
large as 19.5 MW, and could provide the total
propulsion power.
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
61. Azipod drive unit
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
62. Propulsion motor
• For efficient operation of propulsion motor there is a
requirement for a compact, power dense, rugged
electrical machine to be utilized for the propulsion
motor.
• For the full benefits of electric propulsion to be
realized the machine should also be efficient,
particularly at part load,
• In order to achieve suitable compact designs rare
earth permanent magnet materials may be required.
• The machine topologies available for PMM are
deemed to be those based on radial, axial and
transverse flux designs.
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
64. Marine Electric Propulsion
Due to its flexibility, energy efficiency and superior performance,
electric propulsion is widely used in today's marine technology
Functionally the propulsion drive can be divided into following
parts :
• supply transformer,
• propulsion motor and
• frequency converter.
- In an AC drive, a frequency converter is used to control the
speed and torque of electric motor. The speed of the AC electric
motor can be controlled by varying the voltage and frequency of
its supply. A frequency converter works by changing the constant
frequency main electrical supply into a variable frequency output.
- The ideal simplicity of the induction motor, its perfect reversibility
and other unique qualities render it eminently suitable for ship
Propulsion.5/17/2014 64
Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
65. Electric propulsion
- Diesel-Generator sets to
produce electricity to
common grid for propulsion
and ship use.
- Variable speed drives to
rotate fixed pitch propellers.
- Commonly used in Cruise
vessels, LNG tankers, Off-
shore vessels and Ice
breaking vessels due to
reduced fuel oil
consumption, lower
emissions and increased
pay-load
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
66. Generator system of Conventional Cargo Ships
Electricity demand is small.
2 Generators are equipped.
Only one set of either is usually operated.
Gen.
Gen.
Laod A
Laod B
Laod C
440V, 60Hz
Laod D
220V/110V
Photo from <http://ja.wikipedia.org/wiki/>
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
67. Features
Very big (24m, 15m)
Super heavy (2000 ton)
High Power (60,000 kW)
High Efficiency ( over 50% )
Large Diesel Engine for Main Engine
Photo from <http://www.mol.co.jp/ishin/engine/present/index.html>
<http://www.mhi.co.jp/products/detail/mitsubishi-wartsila_diesel_engine.html>
Cleaner transport
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
68. Configuration of Electric Propulsion
System for Ships
Gen.
Gen.
Laod A
Laod B
Laod C
Laod D
Main
Engine
Propeller
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
69. Configuration of Electric Propulsion
System for Ships
Gen.
Gen.
Laod A
Laod B
Laod C
Gen.
Gen.
Power
Converter
Power
Converter
Motor
Motor
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
70. Configuration of Electric Propulsion
System for Ships
Gen.
Gen.
Laod A
Laod B
Laod C
Gen.
Gen.
Power
Converter
Power
Converter
Motor
Motor
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
71. Configuration of Electric Propulsion
Gen.
Motor speed can be controlled by the frequency of electric
power.
Generator outputs constant frequency (60Hz)
Power converter supply suitable frequency and demanded
power
Gen.
Power
Converter Motor
Speed Control
by frequency
Constant
Frequency
60 frequency for
control
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
72. Configuration of Electric Propulsion
System for Ships
Gen.
Gen.
Power
Converter Motor
Power Converter
Converter
60Hz AC DC
Inverter
DC
Various frequency AC
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
73. Configuration of Electric Propulsion
System for Ships
Gen.
Gen.
Laod A
Laod B
Laod C
Gen.
Gen.
Power
Converter
Power
Converter
Motor
Motor
Harmo c
Distor
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
74. Configuration of Electric Propulsion
System for Ships
Special
Transformer for
Power rter
Gen.
Pow
Conver
Gen.
Pow
Conver
Gen.
Laod A
Laod B
Laod CGen.
er
ter Motor
er
ter Motor
Photo from <http://www.risho.co.jp/product/products3/special_use/converter/converter.htm>
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
75. Comparison with Conventional and
Electric Propulsion system
Gen.
Gen.
Laod A
Laod B
Laod C
Gen.
Gen.
Power
Converter
Power
Converter
Motor
Gen.
Gen.
Laod A
Laod B
Laod C
Laod D
Main
Engine
Propeller
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
76. Twin Shaft EL Propulsion
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Mohd. Hanif Dewan, Chief Engineer and
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77. FPSO Electrical system Layout
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Mohd. Hanif Dewan, Chief Engineer and
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78. Shuttle Tanker Electrical System Layout
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
79. Shuttle Tanker Electrical Line Diagram
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
80. Drill Ship Electrical System Layout
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
81. Typical system of all electrical ship
Generator sets complete with prime movers and engine controls
HV/LV Switchboards, distribution systems and group starter boards
Propulsion and thruster motors complete with power electronic
variable speed drives
Power conversion equipment
Shaft braking
Power factor correction and harmonic filters (as necessary)
Power management
Machinery control and surveillance
Dynamic positioning and joystick control
Machinery control room and bridge consoles
Setting to work and commissioning
Operator training
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
82. THE FUTURE
• Propulsion of ships by help of standard diesel engines
usually gives a non-optimal utilization of the energy.
• Today an increased use of diesel electrical propulsion of
ships can be seen. New power electronics and electrical
machines will be developed for propulsion and thrusters,
as well as other application on board.
• Knowledge has to be developed about how such large
motor drives will influence the autonomous power
systems on-board.
• Even development of new integrated electrical systems
for replacement of hydraulic systems (top- side as well
as sub-sea) are becoming areas of need.
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
83. To introduce solar energy to the ship we need to convert the
solar energy to electrical energy. electrical energy we can
use and transport throughout the ship. photo-voltaic cells
convert solar into electrical energy. An inverter is needed to
convert the direct current (dc) to an alternating current (ac),
so the 50 or 60 hz electric grid can transport the electrical
energy through the ship. These energy conversions reduce
the efficiency of the whole chain.
With a dc grid in a diesel-electric propulsion system less
energy conversions are needed, There is no need for bulky
transformers.
WIND & SOLAR ENERGY FOR SHIP
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
84. Ships also can benefit from the sun. The deck of a ship is always
outside in the sun. With a deck area of more than 9000 square
meters for a Panamax sized ship, a lot of energy can be
harvested for free. With increasing PV-panel efficiency and
decreasing cost due to mass production, solar energy can be
beneficial next to existing ways to produce electrical energy.
There are of course some challenges to overcome before
integrating solar energy on a ship, but the maritime industry is
driven by innovation to come with clever solution.
Ship already sailing solely on solar energy is the planet solar.
With its 500 square meters of solar panels and large li-ion
battery, it is accomplishing a journey around the world.
WIND & SOLAR ENERGY FOR SHIP
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
85. Sail and solar power ship
5/17/2014 85
Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
88. POWERFUL - UNLIMITED - FREE
Wind is the cheapest, most powerful, and greenest source of
energy on the high seas. Now, with SkySails, modern cargo ships
can use the wind as a source of power – not only to lower fuel
costs, but significantly reduce emission levels as well.
SKYSAIL TECHNOLOGY
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
89. The worldwide patented SkySails
propulsion system consists of three main
components: a towing kite with rope, a
launch and recovery system, and a control
system for automated operation.
SkySails can be installed effortlessly as an
auxiliary propulsion system on both new
builds and existing vessels.
The SkySails propulsion system is efficient,
safe, and easy to use – and the fact that
wind is cheaper than oil makes SkySails
one of world’s most attractive technologies
for simultaneously reducing operating costs
and emissions.
SKYSAIL TECHNOLOGY
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Mohd. Hanif Dewan, Chief Engineer and
Maritime Lecturer & Trainer, Bangladesh
90. Reference Articles, Books and Websites:
1. Electric Propulsion Systems for Ships by Dr. Hiroyasu Kifune
2. Practical Marine Electrical Knowledge by D.T. Hall
3. www.vht-online.de (Speech by Bernd Röder)
4. www.imtech.com
5. www.skysail.info
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Maritime Lecturer & Trainer, Bangladesh
90