ELECTRICALSECTION

TANK T-72

SAMEER BATRA1051110104

SRM UNIVERSITYCHENNAI

ACKNOWLEDGEMENT

I would like to express my deep gratitude to Brig Ramesh for allowing me to work in the organisation 505 Army Base Workshop , New Delhi. I would also like to thank Col Nanda for patient guidance and encouragement for keeping my progress on schedule. This training would not have been completed without the support of Daf Nikam. I would also like to thank the work force of their respective fields helped me in greatly in the workshop in technical work.

Sameer Batra

CONTENTS

1. Corps of Electrical and Mechanical engineers2. EME history3. Army Base Workshops4. Tank T-725. Tank T-72 Technical data6. Layout of workforce in 505 Army Base Workshop7. Electrical ARD

i) Hornii) Head lightiii) Digital head lightiv) Fansv) BTSN pumpvi) Engine oil primming pumpvii) Transmission oil primming pumpviii) Inertia grill with packingix) Filter radio frequency interference(F5) and filter R.F.I. (F10)x) Marker lightsxi) Mini panelxii) Tachometer sending D4 unitxiii) Blidge pumpxiv) Battery master switchxv) Battery fuse boxxvi) Reduction gear with electrical speedometerxvii) Reduction gear with tachogeneratorxviii) Control panelxix) Convertor PAG 1F

8. Starter generator i) Technical data ii) Layout of starter generator

9. Suggestions to improve efficiency of 505 Army Base Workshop

Corps of Electrical & Mechanical Engineers [EME]

The role of Corps of Electrical & Mechanical Engineers [EME] is to achieve and maintain the operational fitness of electrical, mechanical, electronic and optical equipment of the Army. The Electrical and Mechanical Engineers who light to factory-level repairs to everything the Army uses. With their forward repair teams based on customized armoured vehicles, they function within a battlefield, recovering equipment casualties from their point of collapse. Back at base workshop, they strip and rebuild anything that the Army owns be it fighting vehicles, electronics, or data processing equipment.

The history of the Corps, born in 1943, is indeed glorious. Over the decades, the Corps has, with remarkable speed, welded itself into a fine and efficient organisation. It is imbued with requisite zeal and determination to overcome, if necessary by improvisation, all the impediments it faces in the rapidly changing technological environment. The efficacy with which an organisation performs its role is dependent to a large degree upon the sense of union developed amongst its elements - the esprit de corps. These 56 years have built up traditions and relationships of a lasting kind. These have sustained amongst its troops the concept of honour, courage, fidelity to the organisation, professional integrity and a pride in developing technical skills.

The Corps is responsible for providing engineering support to the army equipment ranging from light vehicles to tanks, guns, missiles, radars, computers, helicopters, communication equipment, night vision devices, simulators and so on during war and peace. Over the years there has been phenomenal rise in the sophistication, quantum and variety of military hardware. The Corps has effectively met the challenges arising from the proliferation of such multi-disciplinary high technology military hardware through continuous evolution of its engineering support system.

There are some schools of thought which maintain that war is just a fight between soldiers in combat arms; this is not the case. It is true that an army is a fighting machine, but there are three basic needs if it is to achieve its full potential in battle - leadership, equipment and training. Wars involve the employment of a great deal of modern and sophisticated equipment and the EME plays a major role in assisting the Army's posture of operational preparedness and combat effectiveness to win any war. If combat arms are the teeth of the Army then EME has a vital function of keeping them sharp. Through the war and the many operations that the Indian Army undertook over the past five decades, the Corps has proven itself as a first class repair, recovery and in many cases as a design and development organisation. It is actively involved in counter insurgency operations both in J & K and in North-East.

EME History

From the role of mere servicing the arms and ammunition, the Corps of Electronics and Mechanical Engineers (EME) rose to the level of managing technology for the Armed Forces. In this odyssey, the corps crossed many hurdles and carved a niche for itself in the service of the nation.

The story of warfare, in essence, is a story of man's struggle for existence. Earlier, man used to shape tools and weapons to outwit his opponents. Later, he projected his need to someone else to make weapons for war. Consequently, the need of craftsman arose.

By the turn of the nineteenth Century, Inspectors of Ordnance Machinery (IsOM) were responsible for repair of guns, small arms and instruments in arsenal workshops in India. Later, in 1925, a new cadre of Ordnance Mechanical Engineers (OMEs) was brought in and the IsOM came on the roll of Indian Army Ordnance Corps. Later, the Supplies and Transport Corps emerged as the Royal Indian Army Service Corps (RIASC). There were 11 transport workshops providing first and second line repair cover to the vehicle fleet. They stocked spares, assemblies and fitment items required for the vehicles. By mid 1942, allied war production gained ground and a large number of equipment like tanks and guns were coming to India for the Allied Forces.

An American Tank Detachment Commander, Lt Col Rothwell H Brown was on duty with the British forces in India for the purpose of advising them on maintenance and operation of armoured vehicles. He suggested the urgent need for improving the efficiency of the mechanical engineering service of the Army.

Accordingly, the Commander-in-Chief of British Forces approved the raising of an equivalent of the REME in India. On May 1, 1943, the Mechanical Engineering Directorate at General Headquarters (India) was formed and units were allocated. On September 15, 1944, Lt Gen Sir Clarence A Bird was appointed as the Colonel Commandant of IEME. The new born Indian Electrical and Mechanical Engineers had the motto omnia fascimus meaning-'We can do everything'.

On October 15, 1943, the actual transfer of personnel from IAOC to IEME took place. This resulted in the birth of the Indian soldier craftsman and since then October 15 is observed as the EME Corps Day.

The nascent Corps almost doubled its strength in a matter of two years to establish 632 different IEME units including 12 training centres, 13 commands, 6 bases and 113 station workshops. The IEME personnel distinguished themselves in every theatre of war where they operated.

When India became a Sovereign Republic in 1950, the Corps dropped "I" from its name to be called as EME. The design of the new Corps badge was to promulgate the ethos of the Corps. The design prepared by Maj SE Doig when Brig IH Reeves was the DME, was approved in 1953 and taken into use from 1955. The motto was also changed to 'Karm hi Dharam' which means-"Work is Supreme Duty".

The advancements in technology in the 80s and 90s resulted in use of electronics in all types of equipment. In tune with the times, the equipment profile of the Army had predominance of electronics which necessitated the Corps to change its outlook from electrical to electronics. In January 2001, the corps was re-christened as the Corps of Electronics and Mechanical Engineers. During last six decades, the corps proved itself with distinction in all the tasks assigned to it.

Army Base Workshops (ABW)

Eight Army Base Workshops (ABWs) were established during the second world war to carry out repairs and overhaul of weapons, vehicles and equipment to keep the Indian Army operationally ready. Towards this end, they also undertake manufacture of spares. The ABWs work under the overall control of Director General Electronics and Mechanical Engineers (EME) who functions under the Master General of Ordnance (MGO). Headquarters Base Workshop Group is responsible for planning and co-ordination of functions of the ABWs.

The ABWs are co-located with the ordnance depots which feed them with repairables and spares. The overhauled/repaired equipment are received by these depots for issue to the user units. The production/repair capacity of ABWs is determined on the basis of manpower and are fixed in terms of standard units (SUs) which is equivalent to 100 man hours. Various committees have recommended norms for the functioning of the ABWs from time to time.

The workshops of EME are the centers where military equipment gets a new lease of life. At present, there are eight Army Base Workshops (ABWs) at Delhi, Agra, Meerut, Kirkee, Jabalpur, Kankinara, Allahabad and Bangalore.

Headquarters, Base Workshop Group located at Meerut coordinates all the activities of ABWs in consonance with the policy laid down by Army Headquarters.

The 505 Army Base Workshop in New Delhi overhauled a variety of 'A' and 'B' vehicles which include Churchill, Stuart, Sherman, AMX-13 and Vijayanta tanks and armoured cars like Diamler, Humber and GM Fox. The workshop has carried out re-powering of Vijayanta tanks with T-72 engines, upgrading them with night vision devices, fire control system and fire detection equipment.

The latest achievement of this workshop is manufacture of Windy-505, a fast attack vehicle. Recipient of ISO 9001 : 2000 certification during 2002-2003, 507 Army Base Workshop overhauls 'B' vehicle engines and also manufactures spares. Its major activity includes overhaul of Kraz vehicles of Army and Air Force.

While 509 Army Base Workshop is a specialist workshop responsible for base repairs of radar systems, electronic test equipments, optical and fire control instruments and night vision devices, 510 Army Base Workshop located at Meerut overhauls air defence and guided missiles systems. It carries out overhaul of Schilka and Kvadrat weapon systems, multi-barrel rocket launchers and specialist heavy-duty vehicles.

The 512 Army Base Workshop takes credit for upgrading T-55 tanks in the 70s under Project May flower and Sun flower. In the late 80s, T-55 tanks overhauled with Polish technology rolled out of its production line. At present, it is undertaking overhaul of T-55 and its variants.

Originally known as 10 Advance Base Ordnance Workshop, 515 Army Base Workshop undertakes repairs of 'B' vehicles, small arms, armaments and engineering equipment. At present, it is manufacturing simulators for the Army and para-military forces. One Advance Base Workshop looks after the equipment in the Eastern Theatre.

EME's 3 Advance Base Workshop undertakes base repairs for units in Northern Command like overhaul of guns and engines. Recently it has become a nodal centre for repair of thermal imaging and electronics equipment. It has also designed, developed and manufactured electronic equipment like Ashi Pillai which has been instrumental in saving valuable lives in counter-insurgency operations.

TANK T-72

The T-72 is a Soviet-designed main battle tank that entered production in 1970. It was developed directly from Obyekt-172, and shares parallel features with the T-64A. The T-72 was one of the most widely produced post-World War Two tanks, second only to the T-54/55 family, and the basic design has also been further developed as the T-90

The T-72 was the most common tank used by the Warsaw Pact from the 1970s to the collapse of the Soviet Union. It was also exported to other countries, as well, such as Finland, India, Iran, Iraq, Syria and Yugoslavia, as well as being copied elsewhere, both with and without licenses.

Licenced versions of the T-72 were made in Poland and Czechoslovakia, for WARPAC consumers. These tanks had better and more consistent quality of make but with inferior armour, lacking the resin-embedded ceramics layer inside the turret front and glacis armour, replaced with all steel. The Polish-made T-72G tanks also had thinner armour compared to Soviet Army standard (410 mm for turret). Before 1990, Soviet-made T-72 export versions were similarly downgraded for non-WARPAC customers (mostly the Arab countries). Many parts and tools are not interchangeable between the Russian, Polish and Czechoslovakian versions, which caused logistical problems.

Yugoslavia developed the T-72 into the more advanced M-84, and sold hundreds of them around the world during the 1980s. The Iraqis called their T-72 copies the "Lion of Babylon" (Asad Babil). These Iraqi tanks were assembled from "spare parts" sold to them by Russia as a means of evading the UN-imposed weapons embargo. More modern derivatives include the Polish PT-91 Twardy and Russian T-90. Several countries, including Russia and Ukraine, also offer modernization packages for older T-72s.

Various versions of the T-72 have been in production for decades, and the specifications for its armour have changed considerably. Original T-72 tanks had homogeneous cast steel armour incorporating spaced armour technology and were moderately well protected by the standards of the early 1970s. In 1979, the Soviets began building T-72 modification with composite armour similar to the T-64 composite armour, in the front of the turret and the front of the hull. Late in the 1980s, T-72 tanks in Soviet inventory (and many of those elsewhere in the world as well) were fitted with reactive armour tiles.

Laser rangefinders appear in T-72 tanks since 1978; earlier examples were equipped with parallax optical rangefinders, which could not be used for distances under 1,000 metres (1,100 yd). Some export versions of the T-72 lacked the laser rangefinder until 1985 or only the squadron and platoon commander tanks (version K) received them. After 1985, all newly made T-72s came with reactive armour as standard, the more powerful 840 bhp (630 kW) V-84 engine and an upgraded design main gun, which can fire guided anti-tank missiles from the barrel. With these developments the T-72 eventually became almost as powerful as the more expensive T-80 tank, but few of these late variants

reached the economically ailing WARPAC allies and foreign customers before the Soviet bloc fell apart in 1990.

Since 2000, export vehicles have been offered with thermal imaging night-vision gear of French manufacture as well (though it may be more likely that they might simply use the locally manufactured 'Buran-Catherine' system, which incorporates a French thermal imager).Depleted uranium armour-piercing ammunition for the 125 mm (4.9 in) gun has been manufactured in Russia in the form of the BM-32 projectile since around 1978, though it has never been deployed, and is less penetrating than the later tungsten BM-42 and the newer BM-42M.

The T-72 shares many design features with other tank designs of Soviet origin. Some of these are viewed as deficiencies in a straight comparison to NATO tanks, but most are a product of the way these tanks were envisioned to be employed, based on the Soviets' practical experiences in World War II. Although it depends less on electricity than some Western main battle tanks, it nonetheless still needs electrical power for operation and movement.

Nuclear, biological, and chemical protection

The T-72 has a comprehensive nuclear, biological, and chemical (NBC) protection system. The inside of both hull and turret is lined with a synthetic fabric made of boron compound, meant to reduce the penetrating radiation from neutron bomb explosions. The crew is supplied clean airvia an extensive air filter system. A slight over-pressure prevents entry of contamination via bearings and joints. Use of an autoloader for the main gun allows for more efficient forced smoke removal compared to traditional manually loaded ("pig-loader") tank guns, so NBC isolation of the fighting compartment can, in theory, be maintained indefinitely. Exported T-72s do not have the internal lining that is standard on Russian T-72s, which consists of a layer of synthetic material, containing lead, that provides some degree of protection against the effects of neutron radiation and electromagnetic pulses.

Interior

Like all Soviet-legacy tanks, the T-72's design has traded off interior space in return for a very small silhouette and efficient use of armour, to the point of replacing the fourth crewman with a mechanical loader. The basic T-72 design has extremely small periscope viewports, even by the constrained standards of battle tanks and the driver's field of vision is significantly reduced when his hatch is closed. The steering system is a traditional dual-tiller layout instead of the steering wheel or steering yoke common in modern Western tanks. This set-up requires the near-constant use of both hands, which complicates employment of the seven speed manual gearbox.

TECHNICAL DATA T-72GENERAL

COMBAT WEIGHT 43.8 TONS

CREW 3

POWER TO WEIGHT RATIO 17.8 hp/t

GROUND PRESSURE 0.86 Kgf/Cm2

DIMENSIONS

LENGTH WITH GUN FORWARDS 9530MM

LENGTH WITH GUN BACKWARDS 9670MM

HULL LENGTH 6860MM

HEIGHT 2190MM

AMMUNITIONS

CAPACITY FOR CARRIAGE 44 ROUNDS

TYPES OF AMN USED APDS,HEF&HEAT

MAX RANGE OF AIMED FIREM-APDS 4000 M

-ADPS 4000 M

-HEAT 5000 M

SMOKE GENERATING EQUIPMENT

NO OF SMOKE GENERATING LAUNCHERS 12

TYPE THERMAL SMOKE GENERATING EQPT

PERFORMANCE

AVERAGE SPEED-CROSS COUNTRY 35-45 KM/HR

-HIGHWAY 50 KM/HR

-MAX SPEED ON HIGHWAY 60 KM/HR

ENGINE AND FUEL USAGE

ENGINE FOUR STROKE

CYLINDERICAL V TYPE

WATER COOLED, CHARGED

MAX HP 780 AT 2000 RPM

WEIGHT 980KGS

CAPACITY 1600 LITRES

FUEL CONSUMPTION/100 KM 260-450 LTRES

HIGHWAY 240 LTRES

STARTING SYSTEM

MAIN COMPRESSED AIR

AUXILARY BATTERY

TRACK DRIVE

TRACK TYPE RUBBER BRUSHED,PARALLEL PIN-JOINTED

NO. OF LINKS 96

LAYOUT OF WORK IN 505 ARMY BASE WORKSHOP

1) Damaged tank

2) Stripping sectiona) Pipe line sectionb) Pneumatic sectionc) Gun controld) Gear boxe) Barrel sectionf) Tank electronicsg) Instrument sectionh) Enginei) Mechanical partsj) FVGCE( fighting vehicle gun control equipment )k) Electrical section (rotables)l) Salvage

3) Hull reclamanationa) Washing and degreasingb) Checking for defects c) Measurements checkd) Paint ( red oxide )

4)Turret washing

5) Rotatory equipment( gun equipment )

6) cradle section

7) Hull assembly + turret assembly

8) Final assembly

9) Testing

ARD – ELECTRICAL SECTIONThe following parts of the T-72 are repaired in the Electrical section of 505 Army Base Workshop. All the devices are tested with DC supply under technical supervision.

1) Horn

2) Head light

3) Digital head light (turret)

4) Fans

5) BTSN pump

6) Engine oil primming pump (E FOPP)

7) Transmission oil primming pump (TOPP)

8) Inertia grill with packing

9) Filter radio frequency interference (F5)

10) Filter R.F.I. (F10)

11) Starter Generator

12) Marker Lights

13) Mini panel

14) Tachometer sending D4 unit

15) Blidge pump

16) Battery master switch

17) Battery fuse box

18) Reduction gear unit with electrical speedometer

19) Control panel

20) Reduction gear unit with tachogenerator

21) Convertor PAG 1F

HORN

The horn is arranged outside the vehicle on the guard of right head lamp The horn consists of a winding where one wire acts as earthing It is checked in the electrical section using DC

HEAD LIGHT

One head lamp (blackout) and one head lamp ( IR ) are installed on the vehicle hull on the front plate

Other head lamps (gunner IR) and (commander s IR) are installed on vehicle turret Head lamp(IR) is intended for illumination of terrain in front of the vehicle Head lamp (black out) is intended for illumination in visible light The only difference b/w IR and blackout head lamp is of the light filter lens else the

construction is same

DIGITAL HEAD LIGHT(TURRET)

Digital head light is of the same construction electrically as of head light It is used to display the tank number The lens is of red colour

FANS

There are 3 fans located in the tank-driver fan ,gunner fan ,commander’s fan The driver fan is located in the drivers compartment The gunner fan is located on the left side of turret race ring The commander’s fan is located on the turret roof It has a positive and a negative terminal which is directly tested using DC supply

BTSN PUMP

The BTSN pump is located near the diesel tank located near to the driver The main purpose of a BTSN pump is to pump the diesel without any impurities .. If any unwanted particle is in the diesel supply then it is filtered. Pump is checked in the electrical section to check for leakage and efficient pumping.

ENGINE OIL PRIMMING PUMP (EOPP) AND

TRANSMISSION OIL PRIMMING PUMP (TOPP)

EOPP and TOPP are required for prelubricating the tank engine therefore it is placed below

the starter generator in the engine compartment These pumps can be stared using the starter push button They have a split series motor with a capacity of 0.5KW and 40 amps The pumps transmit diesel in the of tank The pumps are first separated and the motors are cleaned and repaired manually Then pumps are tested using DC supply for leakage and pumping.

INERTIA GRILL WITH PACKING

The grill is placed above the starter generator which is extended to outside the tank. The basic purpose is to direct the smoke for engine.

FILTER RADIO FREQUENCY INTERFERENCE (F5)

AND

FILTER R.F.I (F10)

This filter is used for reducing the noise interfering with radio reception which appears during the operation of vehicle electrical equipment

Both the filters filter the 24 volt DC supply to avoid any sort of fluctuated supplt to the turret and hull

MARKER LIGHTS

The marker lights are employed in the vehicle for indicating extremities in motion or halt in

night. Six marker lights are provided on a tank. The front are provided with green light while rear ones red light filter. A helical spring is used to ensure protection of lamps against shocks

MINI PANNEL

Mini panel is installed in the driver’s section that controls the indicator light The other lever is used to control gear magnet that helps to keep the speed of tank in check

during frequent gear changes

TACHOMETER SENDING D4 UNIT

A tachometer D4 UNIT is connected to the RPM gauge that indicates the engine speed in the

panel in front of the driver. When the tank is unable to climb a terrain which consists with hills it may start to move back.

As the motor has a property to start when moved in backward direction it can damage the tank parts.

The tachometer sending D4 unit protects tank against reverse starting by expansion of spring which cuts the acceleration.

BLIDGE PUMP

The blidge pump is driven by a series motor with a capacity of 0.3 KW. The pump is located in fighting compartment on left near corner. It pumps any water that may enter the tank during crossing a waterbody out of the tank. The pump contains a motor that runs on high RPM. It is tested using DC suppy for leakage.

BATTERY MASTER SWITCH

The battery master switch is located on the left side of driver’s compartment. It is used to start the engine. The first stage of starting lasts form 3 to 3.8 seconds The time duration is achieved by two micro switches and timer relays

BATTERY FUSE BOX

The battery fuse box consists of 4 MCB’s. It consists of 2 fuse wires which cut in during high voltage supply than rated. It also consists of a shunt. The supply goes to the tank after being through the fuse box.

REDUCTION GEAR UNIT WITH SPEEDOMETER

A speedometer is attached to the engine motor and it measures the speed of the tank.

It is located on the left side of the driver. The speedometer consists pf 4 pin terminal 3 run the meter and one goes to the

supply to run the speedometer. It is tested using the machine designed by 505 army base workshop electrical section

which checks for correct speed measurement.

REDUCTION GEAR WITH TACHOGENERATOR

It is located on the right idler wheel. Generates DC signal proportional to the speed of vehicle moment which is sent to

automatic matching unit. It also controls the relative position of the gun when the target is fixed by the

mechanism called delta-D mechanism. Controls the gear interlock system.

CONTROL PANEL

It is also called as smoke switch The basic function is to launch and indicate the smoke launchers which are attached

on the turret of the tank.

CONVERTOR PAG 1F

It consist of a single armature. Acts as both motor and generator. The main purpose of a convertor PAG 1F is to give constant voltage supply to the turret.

STARTER GENERATOR

TYPE DC,WITH COMPOUND EXCITATIONNO. OF POLES 4 MAIN POLESWEIGHT 70 KG

The starter generator is a DC machine whose excitation is parallel to generation mode and compound in starter mode.

The starter generator is connected gets its drive from gear connecting box.

The cooling of a starer generator is done by means of a centrifugal pump driven by its armature.

The air is first cleaned by inertia grill then it follows two parts. The first part sweeps surface of commutator ,brush holders. The other passes the vent through vent ducts of the armature.

DIFFERENT BEARINGS AND LOCKS USED IN A STARTER GENERATOR

The important function of the statrer generator is to make the voltage supply change from 24 volt to 48 volt during starting by changing the parallel to series setup.

It works on DC supply. An ideal starter generator should be able to perform the charging and give out supply. The generator is opened manually and cleaned and checked for defects and assembled back.

CARBON RINGS

ARMATURE

LAYOUT OF A STARTER GENERATOR

SUGGESTIONS TO IMPROVE THE EFFECIENCY OF 505 ARMY BASE WORKSHOP

1. Use of safety gear should be stressed upon.2. Proper leather shoes with a thick base can be made mandatory to

avoid injuries from heavy tools.3. The variety of tools and spanners available can be improvised.4. The raw materials should be always available in surplus in the store

dept acc to the individual needs of the working staff.5. Receive reports of work done and evaluate performance on a daily

basis.6. Make up daily targets7. Stress on the maintenance of machines also.8. Create an environment that understand the needs of the workforce and

motivates them to work efficient.9. Maintain raw materials stock room.10.The tea time can be made productive for taking reports of the work

done on daily basis.11.Detailed knowledge of all the parts of the tank can be taught to more

persons in charge for a better interaction among workers to increase productivity

REMARKS