A submarine is
basically a watercraft that has the ability of independent operation underwater.
It is dissimilar to a submersible, which has more limited underwater power or
ability. The term most commonly refers to a large, crewed vessel. Submarines
were first widely used during World War
I (1914–1918). Submarines were first built by Dutch inventor Dribble 1633 in the early 17th century, but it was not up to 150
years later for the first time they were used in naval combat. Mostly in the Beginning
in ancient times, humans have tried to work under the water. They have tried to
work from simple submersibles to nuclear-powered
underwater crewed vessels; the humans have searched for a means to remain
safely underwater during warfare and to gain the advantage in warfare, which is
the root in the development of the submarine. This article will deal with
the working, advantages, disadvantages and application of AIP in modern
submarines and compares the Air Independent Propulsion (AIP) system with the
nuclear submarine. An accurate
observation is that submarines designed for different missions possess
INTRODUCTION AND LITERATURE SURVEY:
submarines have become the principal weapon of naval warfare, designers have
focused on making them quieter and increasing their underwater capabilities.
Traditional diesel-electric submarines need surface so that to charge their
batteries and have the capability to remain underwater for only a few days.
technology improved, the endurance of these submarines increased
proportionally. The introduction of Air Independent Propulsion (AIP) vastly
improved the underwater endurance of these submarines and gave them distinct
That is the basic
reason why the world is shifting to AIP system. The best part is that AIP
technology can be installed on existing older generation submarines by
inserting a new hull section during its manufacturing
The need for
doing now of submarine development, as with other military systems, was
driven by the World wars and Cold War, desire
by right improvements in sound effects, weaponry, safety, automation and submerged power. In the years lead up to
and during World War II, over 1000 under sea boats and Diesel submarines were
made by Germany alone (1). During times of the
Second World War, Germany was producing over 35 Diesel submarines per month. In fact, the Total number of earth submarinesmade during WVWII, not including Japan, was well over 2500 (2). Although the chief
place was on quick development and building during the
First World War and the Second World War, under-water boat
vessel designs got
well, especially in weapons and making connections systems. With the
advent of Cold War and the need for longer submerged power, the chief
place changed to nuclear submarine, causing a burst in
production of submarine vessel producing over the next 34 years. From 1955 to
1989 the Soviet Union and United
States alone made over 350 nuclear submarines (3). From a high Cold War world count 1 of 400 nuclear submarines in 1989, there are only approximately 160 today, as
nuclear submarine producing has experience
significant slowdown everywhere on worldwide (3). Building of nuclear submarines is limited to the United
States, Russia, England, France, India and China. In the us, the producing rate of
nuclear submarines is only sent
out to be one per year over the next ten
years. While the nuclear submarine producing rate has dropped lately, Diesel electric
submarine producing rate today is growing. . The world Diesel under-water producing rate is predicted to get
stretched eight per year between 2004 and 2023 (4),
which would increase the world Diesel submarine 1 above 500 in the
next 20 years and now this technology is overcome by diesel
electric with AIP systems. With such systems, Diesel submarines may be suitable for
coastal defense and hence they can easily operate in
oceans. Diesel submarine buildings and structure design vary
according to country to country and type of missions.
.And the Swedish industrialist Thorsten nordenfelt led to the first useful steam-powered under-water, armedwith torpedoes and ready for military use.
The first was nordenfelt I, a 56-tonne, 19.5-metre (64 ft) vessel like to Garrett’s ill-fated resurgam (1879), with a range of 240 kilometres 2 (130 nmi; 150 mi armed with a single torpedo, in 1885.
a safe, good,
ready meansof propulsion 3 for the submerged vessel was only made possible in the 1880s with advent
of electric battery for producing electric
current technology. The first with
electrics powered boats were made by IsaacPeral Y 4 Caballero in Spain, Dupuy de Lome and Gustave Zede in France, and James Franklin Waddington in England. 12 Peral’s
design marked torpedoes and other systems that later
became quality example in submarine 13
Submarines were not put into arm for any stretched
wide regularly order use by navies until the early 1900s.This time marked a most
The Irish inventor
John Philip Holland made a design to
submarine in 1876 and a full-scale account in 1878. In 1896 he designed
the Holland sort V1 submarine, which used internal combustion engine power on
the top and electric apparatus for producing electric current power underwater.
on 17 May 1897 at Navy Lt. Lewis Nixon’s crescent Shipyard in Elizabeth, New Jersey, Holland VI
was purchased by the United States Navy on 11 April 1900, becoming the navy’s
first commisioned submarine 14The Royal Navy given payment for trade five
Holland-class submarines from vickers barrow-in-furness under licence from the
Holland torpedo Boat Company from 1901 to 1903.
As their name suggests,
diesel-electric submarines run on Diesel and electrics. They have a greatly
sized network 1 of electric units which are charged by the Diesel generator.
They snorkel, which means, journeying just below the top of the water with the
periscope 2 and the Diesel generator make pipe above the water top. Once they charge
their batteries, they dive into ocean and run silently on battery power and
their diesel generators are shut down underneath water, After running low
batteries for a few days underwater, the submarines come to surface for
recharging their batteries. diesel-electric submarines are also has relation to
as SSK (sub-surface Hunter-Killer) by us naval.
underwater, the batteries run out of charge
within 4-5 days and the submarine needs to recharge them quickly.this is
basically done by snorkeling which is also an alarm of danger .so that the
submarine is detected by redar and easy target for hostile anti-submarine.but now
a days snorkel are coated with radar absorbing paint and have a secure shaping
but it can be sensed by high resolution radars. now there are also diesel
sniffers that can detect a submarine during its exhaust emission while
snorkeling.the submarines have to come to surface for recharging in this way
they loses their efficiency and increases its suspection to hostile
Hence we need a
system which can let diesel-electric submarines to power up again their
electric units without running their engines. This will let them to continue
sailing underwater and in this way they make
less possibility to be detected.The system should also let the SSKs to greatly
low noise. The system which permits all this is Air independent propulsion (AIP).
submarines offer far better power and speeds , they are quite unsuitable where
the level of water is less and most of navies cant afford to manufactured and
to maintain them as they are very expensive. Also Diesel submarines have the
ability to switched off their engine and lie in water while nuclear submarine
cant switched of their reactors at will. as This grouped together with the
ultra-quiet nature of-the Diesel subs, has made AIP-equipped Diesel subs a very
attractive that possibly taking place in addition for many countries. Many
countries are operating both nuclear and diesel-powered submarines for their
advantages. Navies who wants to operate non-nuclear submarines having longer
–range and large weapons are now option for large diesel submarines having
AIP,which is closest to nuclear powered submarines. Some examples are the Soryu class of Japan, Type
216 being developed by Germany and the Shortfin Barracuda of
France which will be operated by Australia.
before we can get
through working of AIP systems, we need
to know some terms.
Engine: A heat engine in which the working substance is as an unbroken stretch
moved round and does not need replenishment.
Steam turbine : A
sort of turbine in which a high rate of
motion jet of steams used to turn the
turbine blades which in turn makes, goes
round the chief long, narrow rod.The chief long, narrow rod can be connected to
an alternator 10 to produce electricity 11 or to a propeller 1 to move a ship/submarine.
Working fluid: It
is a pressurized gas or fluid that is used to absorb/transmit energy in a thermodynamic
system. Scrubbing: The process of taking away certain gases from the make tired
by the use of right chemicals in a scrubber.
The types of AIP
1 closed cycle diesel
2 closed cycle
3 Sterling cycle engines
4 fuel cells
Closed cycle diesel
In this technology
basically a supply of oxygen is given to submarine to run it while it is
submerged.liquid oxygen (LOX) is stored in tanks on board of the submarines and
it is sent to diesel engine when it reaches to engine then combustion occurs. Then
it is necessary to initialize the atmospheric oxygen to safely run the engine
without geting damaged.the oxygen is mixed with inert gas (argon) and it is
sent to engine. The exhaust gases are cooled and scrubbed so that any extract from oxygen and argon is no more left and the
remaining gases are discharged into sea after mixed with seawater.the extracted
argon is again mixed with oxygen and sent to the diesel engine.
Now the challenging
factor is that the how to store liquid oxygen on board the submarines.the
soviet subs which used this teconology during 1960s found that it is not
suitable to fire and hence they not use further closed cycle diesel AIP is not
preferred for modern submarines inspite of it is comparatively cheaper and
having simple logistics.
CLOSED cycle STEAM TURBINE:
Steam turbines uses
energy as a source to heat water and then convert it into steam in order to run
turbine.in nuclear powered submarine the reactors basically provide the heat to
convert water into steam. but in regular closed cycle steam propulsion a non
nuclear energy source is used to do the same kind of task. The French MESMA(module
d’Energie sous-Marine Autonome/Autonomous Submarine Energy Module) it is the system that uses ethanol and oxygen
as a source of energy. The steam is generated by the combustion of ethanol and
oxygen under high pressure. The working fluid is steam that is used to run the
turbine. The exhaust carbon dioxide is expelled outside into sea at any depth
without using compressor. This is done due to high pressure combustion.
The advantage of
mesma is that it gives higher output as compared to the other all systems that
allows higher speed in under water .its major draw back is that its efficiency
is low .and also oxygen consumption is very high. These systems are also highly complex.theses some drawbacks allows
several navies to opt for sterling cycle
and fuel cell alternatives.
.STERLING cycle ENGINES
A sterling engine
is closed cycle engine .the working fluid is permanently stored in system. The working
fluid is heated by a source of energy so that it in results moves the pistons
and runs the engine. The engine is attached to generator which generates
electricity and in this way battery is charged. The type of source used in this
As an oxidizer and
diesel fuel which is burnt and it generates heat for the working fluid..then
the exhaust is scrubbed and givenout into seawater.
The more chances of
using sterling engine is that it is simple and there is not hard able to use of
diesel fuel and refueling cost is also low when made a comparison with fuel
cells.they are also quiter than mesma for this reason Japanese prefred this
system for their soryu class and Swedish for their Gotlandand Västergötland class
and China for their Yuan class.
main draw back is that they are relatively noisy as compared to fuel cells .the nosie is due to existence of large and
heavy parts.they are also taking much room or space when made a comparison to
operating distance down of under water using sterling AIP is limited to 200m
during AIP system is engaged.
A fuel cell is a
device that converts chemical energy into electrical.This is usually done using
a fuel and an oxidizer. A classic fuel cell converts hydrogen(fuel)
electric energy.The by products are water and heat.
This is done by an
electrolytic cell which consist of two electrodes one is positive(anode)and
other negative(cathode).it is separated by an electrolytic.the reaction between
cathode and anode produces an electric
Current and it is
used to charge the batteries..the speed of reaction is enhanced by chemical