The Ordnance Factory Board (OFB) is the only battle tank manufacturer in the country. It is also the largest defence equipment manufacturer under the Department of Defence Production (DDP) of the Ministry of Defence (MoD). The OFB has 41 ordnance factories with 210 years of rich experience in manufacture of defence equipment, today worth about Rs 15,000 crores annually.
OFB ranked 37th among the world’s top 100 arms producers in 2017, according to SIPRI, a Stockholm-based think tank. Its products include a wide range except for the aviation sector.
The Heavy Vehicles Factory (HVF) was established in 1965 for the production of Vijayanta tank. It has been manufacturing main battle tanks (MBT) for over 55 years and has an assembly line for the licensed manufacture of T-72 and T-90 tanks under transfer of technology (ToT) from Russia. It also manufactures the Arjun Mk-1 designed by the Combat Vehicles Research & Development Establishment (CVRDE) of the Defence Research & Development Organisation (DRDO). HVF’s annual value of products issued is over Rs 2600 crore. Since 1966, HVF has manufactured over 4600 tanks.
Tank Manufacturing is a Complex Art
Manufacturing of tanks is not only a science but also an art. The tank has to perform under rugged terrain condition and, hence, the design has to be failsafe. The tank requires multi technologies for design and manufacture – hence, synergy amongst stakeholders is important.
The demand fluctuates and is driven by the availability of government funds. Sometimes the order quantities are small and economy of scale cannot be maintained. The development cycle is long. Attaining expertise is possible only through repeated orders.
Maturity and integrity of industry is essential for manufacturing of quality tanks. The tank has to be sustained and maintained with supply of spares for the next 30 years.
Duplication of unique infrastructure at original equipment manufacturers/ vendors may lead to underutilization of national resources and uneconomical production. The machines are unique and expensive – hence, investment by many vendors needs critical examination.
Tank Building Challenges
Tank building involves 75 major assemblies (codes) consisting of over 20,000 components. It involves an association of 17 Ordnance Factories, five Proof Ranges, 4 public sector undertakings, over 250 private Indian industries, five laboratories of DRDO, five Authorities Holding Sealed Particulars (AHSP) of Directorate General of Quality Assurance (DGQA) and ToT provider.
The lead time is 30 months for an established production line. All along there is performance evaluation of major systems in the respective factories and proof ranges. There is also performance evaluation at select intermediate stages and at the final stage by respective AHSP (DGQA).
At the time of delivery to the user, a joint receipt inspection by a nominated Army unit is carried out to check for rugged quality and reliability in war
The HVF has to vary out in-service upgrades and improvisations for Indian terrain conditions, ensure supply of spares for life time and after sales service in the field. This is possible only with continuous institutionalized interaction with users in the field and depots.
Manufacture of Hull and Turret
Manufacture of hull and turret requires highly skilled armour welders, heavy fabrications, material handling, large sized heavy duty critical machines, huge fixtures and manipulators.
Some critical components are required like turret castings, NBC pads, Textolites, etc. Some of these components require high precision of 25 micron and positional tolerance of 25 to 50 micron.
Machining conditions are touch due to rapid heat ablation (RHA), heat affected zones and handling of hazardous materials like sealant for fitment of NBC pads. Interestingly Kanchan armour is required to be filled with foam to keep it intact for MBT Arjun turrets.
Manufacture of Gear Box
The tank gear box is an integrated system of gear shifting, clutching, steering and braking mechanism. Five planetary gear trains are arranged in a line and integrated one to another. Special gears of higher bearing load capacity are required with high accuracy.
The system is integrated with hydraulics and Planetary system after multiple heat treatment operations. Non-standard bearings, ceramic clutch plates and special rubber items are used with longer storage and shelf life.
Springs material as per Russian (GOST) specification is not available in the Indian market.
Hard chromium plating with porous chromium surface is used as bearing surface. This porous chromium operation is a patented operation developed by Russians, specially for this high thrust load application.
In sum, high precision machines and highly skilled manpower is required for manufacturing the components and assembly of gear box.
Manufacture of Suspension System
Major components of the suspension system are manufactured in-house. With major assemblies being manufactured by other ordnance factories. Some of the major assemblies are procured from trade. Some of the major assemblies are yet to be indigenized and are being imported.
Integration of Multiple Technologies
Integration of the main and secondary armaments poses certain challenges. All of these armaments have their own characteristics. A tank is equipped with Main Gun (125mm) firing different types of ammunition (HE, HEAT, APFSDS), 7.62 mm machine gun and 12.7mm machine gun.
Amongst the numerous systems and assemblies that need to be integrated are mechanical and hydraulics components, the power pack, transmission system, suspension, drive mechanisms, electronics and electrical systems, fire control system, automatic gun laying system, stabilizer, all control units, engine start mechanisms, opto-electronics and sighting devices, pneumatic systems, NBC system and fire fighting systems.
Challenges of Supply Chain
There are more than 20,000 components being supplied by 400+ vendors. That itself poses logistics challenges of supply time lines and quality control to synchronize with assembly targets. Some items have low and unattractive quantities plus cyclic business constraints. Quality control has to be exercised with multiple vendors. Each new vendor affects reliability of tank performance. Sometimes the exact Indian equivalent of material required is not available. There are financial constraints due to high quality and long gestation period for MSME vendors. Gaps in orders creates difficulties of keeping vendor interest alive. Development of new vendor involves very long duration and very expensive performance and field trials
Most of electronic and electrical systems are built using Russian power relays and logic relays – these are difficult to procure of current vintage. Change over to digital solid state electronics using black box concept will need initiatives by industry. There are also challenge to commit for R&D and investment for limited numbers.
The Future Tank
The proposed futuristic tank can reach the goal post of success only if the development project is led by the user and supported by the DRDO and OFB with partnership of private industry. The work centres with defined responsibility of each stakeholder can be identified. A policy of long term orders and continual upgrades in phased manner will encourage gradual technological advancements in country.
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Five Axis Plano Miller at Heavy Vehicle Factory Avadi.
Side Gear Box With Final Drive and Pump
Engine (left) of the T90 Bhisma tank is manufactured by Engine Factory Avadi and the Intermediate Gearbox (right) is manufactured by another ordnance factory
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Some of the Major Assemblies Manufactured In-house
Turret Traverse Mechanism
Turret Race Ring Assembly
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Some of the Components Not Yet Indigenised and Imported
Automatic Unit P13
Gyro Compass GPK-59
PKUZ-1A
Pre Heater
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T90 Bhisma Tank Sights
Commander Sight
1A43 FCS For Gunner
TI-ESSA Thermal Sight
PZU-7 Anti-Aircraft Sight
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Infrastructure at Heavy Vehicle Factory, Avadi
• 4 guide way lathe for barrel turning
• Barrel straightening
• Recoil manufacturing SPMs (taper grooves)
• CNC plasma cutting and Laser cutting
• Armour steel casting and welding
• Torsion bar making
• Heavy duty gear shaping
• 5 axis plano miller (10m X 5m) for machining 15 MT hull
• Robotic welding
• Vacuum coating for anti-reflection and band specific
• Mil grade electronic assembly and manufacturing
• Anti-static and clean room of class 100 (max 100 particles of 0.5 micron in 1 cub mtr)
• Tank testing track (2 km length)
• Proof ranges
• Special Manufacturing Technologies
• Cold swaging of barrel
• Helical bevel gear manufacturing
• Optical polishing up to accuracy of wave length/20
• Metallic and dielectric multi-layer coating (up to 99 layers)
• Laser rod manufacturing (for LRF)
• Protective glass manufacturing up to parallelism of 20 s
• Manufacture of ESR steel
• Heat treatment of barrels (10 metres long)
• Fracture toughness test equipment
• Radial forging of barrels
• Autofrettaging of barrels
• Rifling of barrels
• Deep hole drilling up to 10 metres
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Some of the Items Sourced From Trade
Driver Instrument Panel
Distribution Box
Aviation Compressor
Tadiran radio set
Roadwheel assembly
Rack radiator assembly
Track Assembly
Periscopes
GPS
1KW Genset
Haydraulic booster
