505 Army Base Workshop

INDIAN INSTITUTE OF TECHNOLOGY DELHI Department of Mechanical Engineering MET 420 Summer Internship 505 Army Base Workshop

Avnish Gaur (2010ME20769) Industry Supervisor: Lt. Col. Harsh Agarwal

About the Workshop

Overhauling of Tank T-72, T-90, Scania, Tatra, Bridging Equipment.

The tank is an industry in itself. There are a lot of parts or assemblies are in a tank. India imports the battle tanks from Russia so assemblies and parts are made there.

Imported tanks from Russia 30-40 yrs. ago are repaired, reclaimed here and then send back to the army and this saves a lot of money of our govt.

When tank’s life deteriorated to the much extent, then giving a new life is the overhauling.

Tank

• Three main requirements are Mobility, Firing Power and Protection.

• In T-72, capacity for 3 people. Commander, Driver and Gunner.

• Gunner is responsible for laying the gun.• Driver drives the tank, and also serves as day to day

mechanic.• The commander is responsible for commanding the tank.

The commander is provided with all round vision devices rather than the limited ones of the driver and gunner.

Driver

CommanderGunner

Components of Tank

Hull

Components of Tank

Turret

Components of Tank

Internal Combustion Engine

Components of Tank

Caterpillar Tracks

Project

• Study and analyse the Gun Stabilization System and suggest some improvements to it.

• This is the heart of the Gun Control equipment (which itself is the most important component of a Tank) and is responsible for stabilizing the turret and gun of the tank.

• Create a testing jig to test the electronic parts of the Gun Stabilization System during time of emergency.

Study of Gun Stabilization System

Gun Control Equipment

Stabilization System ALG Unit

Auto Loading Gun Unit

Gun Control Equipment

• One of the 4 components of the Tank Control System.

• It has 2 components which together performs the job to enable remote and targeting of guns against tanks, aircraft, and shore targets.

• It performs the same task as a human gunner firing a weapon, but attempts to do so faster and more accurately.

Tank Control System

Gun Control System/Equipment

Feedback System

Nuclear Biological Chemicals System

Active Protection System

Stabilization System

Traverse Unit

Elevation Unit

Problem Statement

• Can we test the electronic parts of stabilization system of tank without completely disassembling it?

• There are some dedicated testing jigs in the workshop, which require the tank to be completely disassembled for testing.

• But suppose, there is some emergency problem during a war, or we want to figure out the exact location of the problem.

• In the current scenario, we would have to send the tank to the workshop and completely disassemble it.

• Only if we have a small portable device which can be quickly plugged in to find the root of the problem.

Portable Testing Jig

Portable Testing Jig

• Also called Built-in testing Equipment (BITE)• A built-in test equipment (BITE) or built-in self-

test (BIST) is a mechanism that permits a machine to test itself.

• The main purpose of BITE is to reduce the complexity, and thereby decrease the cost and reduce reliance upon external (pattern-programmed) test equipment.

Components of Stabilization System

Elevation Unit• This unit is responsible

for the vertical movement of the gun.

• It comprises of Elevation Booster (like PWDM in Traverse unit), Actuating Cylinder (elevates the gun) and Gun.


Traverse Unit• This part of Stabilization

System rotates the Turret through 360o.

• It consists of PWDM (Pump with Dry Motor), High Torque Motor and Turret.


K-1 M Box• Heart of stabilization system.• It is also called the First

Distribution Box.• K1M box is the most

important component of stabilization system.

• It contains all the relays, microcontrollers, ICs of the system, and manages all the input and output signals.


LAT (Linear Acceleration Transmitter)• Its function is to

maintain the balance of turret in fixed position during jerks and pit holes, and provide gun enough power to maintain its position during tilted paths.


GSD (Gun Setting Device) • Its function is to bring the gun at 4.50 and freeze it

until new round of ammunition is loaded. • Whenever commander presses a button of

particular ammunition, GSD ensures the gun comes to a position of 4.50 and holds it there till the ammunition is loaded, and then releases it.

Working of Stabilization System• K1M Box is responsible for all the inputs and outputs. It receives input

signal if Commander presses button to load ammunition, or driver rotates the turret, etc. and performs the desired action.

• To rotate the turret, K1M Box sends electrical signal to PWDM and it converts the electrical signal to corresponding hydraulic force.

• High Torque Motor uses the signal sent by PWDM to rotate the turret• Similar process is followed in the elevation side which is responsible for

the vertical movement of Gun.• The Elevation Booster receives the electrical signal and converts it to

corresponding hydraulic force.• The Actuating Cylinder expands or retracts and varies the elevation of gun.• Battery supplies 24V DC supply to Convertor which converts it to 40V AC

supply at 500 hz frequency, and supplies it to K1M box.

W-6 male connector

W-2 and W-6 female sockets

T-72 Range Finder

Gunner’s Range Finding Unit TPD-249• 1000m-4000m• Sets the gun on the target. • The unit combines the properties of an optical Gyro

stabilized sight whose field of view is stabilized in elevation, and of a monocular stereoscopic range finder.

Δ-D Mechanism• Maintains the gun on target despite the movement of

tank.

ΔD mechanism

• Consists of techno-generator and the cosine potentiometer.

• Together they form a feedback mechanism, and keep the gun on target.

• In automatic mode of operation, when the gun is laid on a ranged target, the gun should remain laid even if there are range variations due to the movement of own tank (provided the target doesn’t move).

• At the time of ranging, the range arrow of the gunner’s ranging sight would be coinciding with the target.

ΔD mechanism• When tank moves from its position ‘A’ to a new position ‘B’ through a

distance ‘D’, the technogenerator generates a proportionate voltage corresponding to the distance ‘D’ moved by the tank and feeds it as input to the cosine potentiometer.

• When the gunner traversed the turret through the angle ‘Ɵ’, the output of cosine potentiometer is the cosine function of the input voltage and a DC voltage is accordingly fed to the range motor located inside the sight unit.

• The range motor rotates and causes the range scale to rotate proportional to the voltage generated by the technogenerator and cosine potentiometer.

• Rotation of range motor alters the line of sight. This variation of LOS moves the gun to a new position, therefore super elevation of gun changes, which caters for the increase/decrease in range automatically.

Working of Testing Jig

Parameters for testing• DC voltage supply 24v and AC 40v• High Tension voltage should be 300V DC• Gyro signal range: 0-10v• LAT signal range: 0-10v• GSD signal: 24v should be the output• Compensator output: 0-450mV both side up &

down.


DC/AC Supply Checking• The DC range should be around 22-28 V.• The AC range should be around 38-44 V.• In case of any error, the possible reason could be

that convertor is damaged.

LAT Signal• Range should be around 0-10V.• It is checked on W2 12th pin.


Compensator• Range should be 0-450 mV.• Checked on W6 (pin 39 with 2, 3 shorted) for up• Checked on W6 (pin 39 with 4, 5 shorted) for down

GSD Signal• 24 V optimum• Checked on W2 19th pin.• In case of error, electromagnet might be damaged.


Traverse Output• Optimum Range 6V-35.5 V• Checked on W6 (pin 14 with 23, 24 shorted) for left• Checked on W6 (pin 14 with 25, 26 shorted) for right• In case of any error, change amplifier power

Elevation Output• Optimum Range 6V-35.5V• Checked on W6 (pin 17 with 10, 11 shorted) for up• Checked on W6 (pin17 with 12, 13 shorted) for down• In case of any error, change amplifier power

Issues at ABW

• Improper infrastructure and tools.• Unorganized.• Missing coordination between ground level

employees and officers.• Lacking innovation.• No training or personal improvement culture.• Low investments lead to poor quality of

service, which hampers the defence.

Supply of Materials

Demand of workers

OSS (Ordinance Store Section)

COD (Central Ordinance Depot)

Ordinance FactoryLocal Purchase or

Manufacturing

Goods

If available

If not

If available

If not

Ordering New Material

Section In-charge Overall In-charge Lt. Col. Harsh Agarwal

Product ManagerMain Control OfficerQuotation Call

Lowest bid winsCompanies will bidTakes approximately

36 months

Need of the moment

Innovation

Challenge & Improvement,

Deming’s 14 pts.Motivation at the ground level. Work culture. Show

them success.

Basic tools and infrastructure.

Motivated team of leaders Ex. CEO, CTO, Colonel, Commander

Education

505 Army Base Workshop