12. Design NBC protection.pptx

8/10/2019 12. Design NBC protection.pptx

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Prof James K Varkey30 Dec 14

Chance of Hit Theory
http://en.wikipedia.org/wiki/File:2013_Moscow_Victory_Day_Parade_(28).jpghttp://en.wikipedia.org/wiki/File:Leclerc-IMG_1744-b.jpghttp://en.wikipedia.org/wiki/File:Arjun_MBT_bump_track_test.JPGhttp://en.wikipedia.org/wiki/File:Leopard_2_A5_der_Bundeswehr.jpg


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Armour Layout and Hull Design

1. Design of Hull as per Whittakers DPV

Theory

2. Effect of Sloping of Armour on Layout and

Design of Hull

3. Optimization of Armour layout and Hull Design

4. Design of ICV hull as per Aluminium based

Armour

Revision


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Design for Nuclear, Biologocal

and Chemical Protection

NBC Threat

Different types of Radiations

NBC Systems in the Tanks

Sensors for Nuclear Radiations

System for Air Filtration

Anti-nuclear Treatment


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and Chemical ProtectionNBC Threat

The mushroom cloud of the atomic bombing of Nagasaki, Japan on

August 9, 1945 rose some 18 kilometers (11 mi) above thebomb's hypercentre.
http://en.wikipedia.org/wiki/File:Atomic_blast_Nevada_Yucca_1951.jpghttp://en.wikipedia.org/wiki/File:Atomic_blast_Nevada_Yucca_1951.jpghttp://en.wikipedia.org/wiki/File:Atomic_blast_Nevada_Yucca_1951.jpghttp://en.wikipedia.org/wiki/File:Atomic_blast_Nevada_Yucca_1951.jpg


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A nuclear weaponis an explosive device that derives its destructive

force from nuclear reactions, either FISSION or a combination of

fission and FUSION.

Both reactions release vast quantities of energy from relatively smallamounts of matter. The first fission ("atomic") bomb test released the

same amount of energy as approximately 20,000 Tons of TNT

The first thermonuclear (HYDROGEN) bomb test released the same

amount of energy as approximately 10,000,000 tons of TNT.

A modern thermonuclear weapon weighing little more than 2,400

pounds (1,100 kg) can produce an explosive force comparable to the

detonation of more than 1.2 million tons of TNT.

NBC Threat


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Even a small nuclear device no larger than traditional bombs can devastate an

entire city by blast, fire and radiation.

Nuclear weapons are considered weapons of mass destruction, and their useand control have been a major focus of international relations policy since their

debut.

Only two nuclear weapons have been used in the course of warfare, both by

the USA near the end of World War II.

On 6 August 1945, a Uranium gun-type device code-named Little Boy" was

detonated over the Japanese city, Hiroshima.

Three days later, on 9 August, a Plutonium implosion-type device code-named

FatMan" was exploded over Nagasaki, Japan.

These two bombings resulted in the deaths of approximately 200,000 Japanese

peoplemostly civiliansfrom acute injuries sustained from the explosions.


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There are two basic types of nuclear weapons: those which derivethe majority of their energy from NUCLEAR FISSION reactions alone,and those which use fission reactions to begin NUCLEAR FUSIONreactions that produce a large amount of the total energy output.

Fission weapons

All existing nuclear weapons derive some of their explosive energyfrom nuclear fission reactions. Weapons whose explosive output isexclusively from fission reactions are commonly referred to as atomic

bombsor atom bombs(abbreviated as A-bombs).

The most commonly used fissile materials for nuclear weaponsapplications have been URANIUM -235 and PLUTONIUM -239.


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Fusion weapons

The other basic type of nuclear weapon produces a large amount of itsenergy through nuclear fusion reactions. Such fusion weapons are

generally referred to as Thermonuclear Weapons or more colloquiallyas Hydrogen Bombs (abbreviated as H-bombs), as they rely on fusionreactions between isotopes of Hydrogen (deuterium and tritium).

However, all such weapons derive a significant portion, and sometimesa majority, of their energy from fission. This is because a fission weapon is

required as a "trigger" for the fusion reactions, and the fusion reactionscan themselves trigger additional fission and sometimes a majority, oftheir energy from fission.


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Effects Of Nuclear Explosions

The energy released from a nuclear weapon detonated in the troposphere can

be divided into four basic categories

Blast - 40-50% of total energy

Thermal effects - 30-35% of total energy

Ionizing radiation - 5% of total energy (more in a neutron

bomb)

Residual radiation - 5-10% of total energy

Nuclear weapons have yields varying from KT to 100s of MT.

In the context of AFVs, what is important is Tactical Nuclear Threat, the

yield of which can be assumed to be near 20 KT.

Hence AFVs are generally designed for nuclear protection against a 20

KT weapon burst at about 1850-2000 feet high.


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and Chemical ProtectionEffects of Nuclear Explosion

Depending on the design of the weapon and the environment in which it is

detonated the energy distributed to these categories can be increased or

decreased. The blast effect is created by the coupling of immense amounts

of energy, spanning the Electromagnetic Spectrum, with the surroundings.

Of the total energy released in the explosion, contribution of kinetic

energy is the highest. Because of the very large energy which is initiallycontained in a relatively small volume, the temperature in this volume

becomes very high- tens of millions of degrees centigrade.

The war head debris and the surrounding materials such as air, rock, orwater, interacts rapidly with this fire ball and heats it to an equilibrium

temperature (i.e. so that the matter is at the same temperature as the atomic

bomb's matter).

This causes vaporization of surrounding material resulting in its

rapid expansion. Kinetic energy created by this expansion contributes to the

formation of a shockwave.


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The spherical shock wave so formed with its associated pressure and wind

leaves the fire ball and travels away from the burst. This blast wave carries

about 50% of the kinetic energy which produces blast effect.

The high velocity and the pressure of the shock wave will damage and

displace the AFVs and other military equipment.

Most of the material damage caused by a nuclear air burst is caused by a

combination of the high static overpressures and the blast winds. The

long compression of the blast wave weakens structures, which are then torn

apart by the blast winds. The compression, vacuum and drag phases together

may last several seconds or longer, and exert forces many times greater thanthe strongest hurricane.

Acting on the human body, the shock waves cause pressure waves through

the tissues. These waves mostly damage junctions between tissues of

different densities (bone and muscle) or the interface between tissue and

air. Lungs and the abdominal cavity, which contain air, are particularly injured.

Effects of Nuclear Explosion


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and Chemical ProtectionNBC ThreatEffects Of Nuclear Explosions

BlastThe main considerations are:

1. The tank as a structure must withstand the static over pressure and

individual fixtures may have to withstand reflected pressures upto 8 times

the static pressure.

2. If the tank is Closed Down, aerials, mounts, sighting mechanisms,

machine gun mounts, lights, road wheels, suspension etc. are vulnerable to

damage. Skirting plates tools and tool boxes and other fixtures may be torn

off and thrown away.

3. If tanks not properly closed down will suffer severe internal damagethrough the blast wave entering ports and hatches.

4. Fighting compartment should be isolated from engine compartment by a

well sealed bulkhead.

5. Inescapable openings in the turret and hull should be sealed by shuttering

devices. When radiation from explosion which travels at the speed of light

reaches AFV, the same can detected and automatic device can close downtank to protect from blast wave.


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Thermal EffectsIf the tank is in closed down condition, thermal effects are not too damaging.

The paint may char which may start secondary fire. Camouflage nets are

vulnerable.

Crew may be blinded by the flash effects especially if any one looking in the

direction of fire ball.

Here again shuttering devices may be effective as maximum flash intensity

does not occur immediately the explosion occurs, but after a small intervel oftime. By this time the shutters can be down as the radiation has already been

detected.


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Radiation Effects: Immediate Radiation

Emitted with in one minute of the burst directly from fire ball

contains approximately 1/3 rd of the total radioactive energy.

Alpha and Beta radiation do not pose a threat. Gamma radiation is

attenuated by armour steel. Shielding against neutrons is most difficult

since it require light materials containing hydrogen.

Steel lined with boronated polyethylene provides good protection

against both gamma radiation and neutron fluxes. Polyehtlene lining

could be sprayed outside the tank and crew members could beprovided with AtomicSuits.

Boron or cadmium could be added to armour steel as one of alloy

elements to improve protection against neutrons.

Use of lead glass in sights and periscopes provide protection against

gamma radiation.


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and Chemical ProtectionNBC Threat Effects Of Nuclear Explosions

Radiation Effects: Residual RadiationEmitted after more than one minute after the burst and generally

from fall out

The dangers are:

Parts of tank becoming radioactive due to immediate radiation.

Possible ingress of radioactive fallout in to crew compartment.To prevent parts of the tank becoming radioactive, the best method is to

choose materials that do not easily become radioactive. For e.g use of

aluminium instead of copper for electrical wiring.

Shielding of components likely to turn hot. For e.g Motors

However items like tracks would have to be changed at decontaminationcentres.

To prevent ingress of radioactive fallout in to crew compartment, isolate

it from engine compartment by air tight bulk head

Provide ventilation blower that will induce fresh air for crew and

pressurize fighting compartment.


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Closed Down Condition

When expecting an enemy nuclear strike or when traversing through a

contaminated zone the crew have to resort to closed down living for

considerable length of time may be up to 48 hours.

Chemical and Biological Warfare Protection

Protection against these involve similar measures to the

protection against radioactive fallout i.e. Pressurization and

filtration. But the filtration process is different.Against chemical warfare components activated charcoal is the

known filter.

For biological agents micro-porous paper is generally used.

NBC Threat


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NBC Threat Alpha Radiation- Consists of a stream of alpha particles

(nucleus of helium atom composed of 2 protons and two

neutrons) Very low penetrating power

Beta ParticlesConsists of a stream of beta particles

i.e. electrons which have negligible mass and minus

charge

Gamma radiationIt is electro magnetic waves similar

to X-rays with shorter wave lengths and high penetrating

power Neutron RadiationIt is a particle of unit mass but no

charge and forms part of nucleus


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NBC ThreatSensors for Measuring Radiation

Major types of detectors are:

Gas filled detector (counts the ions)

Solid state detector (Germanium and silicon)

Scintillation detector (on absorption of ionizing radiation

it will shine)

Organic

Inorganic


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Commonly used gas filled is The GeigerMller counter, also called a

Geiger counter.

It is an instrument used for measuring ionizing radiation.

It detects radiation such as alpha particles, beta particles and gamma raysusing the ionization produced in a GeigerMller tube, which gives its name

to the instrument. In wide and prominent use as a hand-held radiation

survey instrument used in Armoured fighting vehicles.

It is perhaps one of the world's best-known radiation instruments.

Sensors for Measuring Radiation


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Design for Nuclear, Biological and

Chemical ProtectionGeiger Muller Detector


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12. Design NBC protection.pptx

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