Jun 13
PMSC Coimbatore – Locked & Loaded
PMSC Coimbatore – Locked & Loaded​​

Watching a 5-axis vertical machining centre in action can be strangely hypnotic. Peering through its ever so lightly tinted operator window as an unwieldy mass of solid metal gets machined and carved into something shapely and useful by a robotic arm as liquid coolant is showered on it from different directions, one can't help but marvel at the definitiveness of mechanical arrangements, the quiet certainty of robotics. It is visual poetry, reminiscent of the space-docking sequence from Stanley Kubrick's 2001: A Space Odyssey where machines go about their work silently as Johann Strauss II's Blue Danube plays in the background. ​

Few seconds and a first-timer is lost into the imagery. The men working on the shop floor of the machining centre at Precision Manufacturing & Systems Complex (PMSC) Coimbatore however don't seem too fussed about the lyrical virtues of a high-end machining centre. For them it is simply sculpting a component that is going to be used in an assembly later. For their mechanically inclined sensibilities, it is business as usual.

Spread over an area of roughly fifty acres within the much larger Coimbatore Campus, PMSC is a unique experiment dating back to the days of Lakshya I. Set up as part of Heavy Engineering's Defence and Aerospace (D&A) SBG, the facility manufactures critical sub-assemblies and assemblies used in the burgeoning defence and aerospace sector. Part of a larger strategic play, not just for Heavy Engineering but L&T as a whole, the facility was born out of the need to develop high-tech manufacturing chops in the emerging precision defence aerospace systems business – an arena in which L&T did do development work a decade or two back but could not scale it earlier.

While D&A had been working closely with DRDO in developing strategic air defence projects since the 1980s, those engagements were often limited to prototyping and did not entail serial production in any. However, with the opening up of Indian defence sector to private participation in the early 2000s the management at L&T sensed a long-term opportunity in serialised production of precision systems. A domain requiring an entirely new set of skills, capabilities and expertise, serialised manufacture of precision equipment was a radical idea. There were no precedents, no legacies which the company could rely on. No internal resources that could be pressed into action and attain global scales in serialising production of defence aerospace systems like missile propulsion airframes. Everything needed to be built from the ground-up and scaled with innovation commitment and passion to surpass the best anywhere across the world in that domain.

A dedicated unit, it was decided, would be put up in Coimbatore since it offered the most convenient location within the “Aerospace Quadrangle" formed by major metros of Bangalore, Hyderabad, Trivandrum and Chennai. Often referred to as “Manchester of South India", Coimbatore houses more than 25,000 SMEs, a majority of whom specialise in precision machining and fabrication. The city is also home to more than 70 engineering colleges which meant that finding local engineering talent wouldn't be a problem. Its proximity to the east and the west coast ports of Cochin and Chennai and an air cargo base promised considerable operational advantages especially when it came to movement of goods and materials. Another unique advantage offered by Coimbatore was the local environment - with minimum variation in temperature over the 24 hours of a day and even climate throughout the year, it was perfectly suited for high precision closely toleranced aerospace production.

PMSC, even before it formally took shape, at its very core had been driven by a vision of making the nation safer and stronger by catering to its defence needs indigenously. Since going operational some eight years ago, the one-of-its-kind facility has grown steadily to build for itself an impressive portfolio of expertise scarcely available in the global market.

At the heart of PMSC's operations lies its innovative EMP cell which develops core process technologies and is responsible for prototyping and turning prototypes into products that can be produced serially. Guided by D2MQC concepts (Design to Manufacturability, Quality & Cost) PMSC's core capabilities cover understanding customer specifications and requirements and turning those into reality through manufacturing design, process reengineering, automation to scale up seamlessly while enhancing reliability, quality and cost competitiveness to deliver customer success.

Within the EMP cell, a vendor-development sub-cell focuses on the same objectives through a judicious mix of in-sourced and out-sourced programme partners. Besides, a special processes sub-cell focuses on studying the developing technologies/processes which could become qualifiers, create differentiators to evolve future order-winners.

The core areas of operation at PMSC include precision machining, precision fabrication, special processes such as heat treatment, surface treatment, assembly-integration, and product validation.    

The Precision Machining Shop at PMSC is capable of machining components and assemblies with tolerances from 1 to 50 microns on materials including Aluminium, Titanium, Steel Alloys and Inconel. The temperature controlled facility scores high on quality and reliability. It houses high-end CAD/CAM systems integrated with high-precision 3/4/5-axis CNC machines that include turn-mills, 3, 4, and 5-axis machining centres,  jig-boring machines, EDM-die sink, EDM-wire-cut, surface grinding, cylindrical grinding and set of conventional machines for rough machining operations to minimise the cycle time on high precision low metal removal finishing machines . The shop is capable of machining components up to 3m long.

PMSC houses a Precision Fabrication Shop capable of welding exotic materials like Titanium, Aluminium, Aluminium Alloys, and specially formulated Steel Alloys.  Over the years, the shop has developed expertise in the areas of welding, brazing and sheet metal forming for flight systems fabrication. The welding processes include Manual/Auto TIG, SMAW, Spot Welding and Orbital Welding. The facility is also equipped with a 6-axis welding robot. The welding stations are equipped with task-specific tooling/fixing and welding automation systems and the manufacturing stations are grouped into cells in an intelligent layout to enhance the production flow on the shop floor.

Altering or enhancing the intrinsic metallurgical properties of material is critical for high-performance aerospace parts. To this end, at PMSC a wide variety of heat treatment methodologies are employed as enhancers for precision fabrication. PMSC has developed heat treatment processes including carburizing, nitriding, hardening, tempering, annealing, as well as heat treatment in controlled atmospheres such as argon, nitrogen. The facility features a vacuum furnace, water-quench furnace, oil-quench furnace, quench bottom furnace, aging furnaces and a cold box. The furnaces are calibrated as per AMS 2750 every month and have been maintaining a class 2 status (less than +/- 6 deg C of temperature uniformity).

Aerospace components must be able to withstand harsh environmental conditions when in use and still retain their aerodynamic integrity despite wear & tear. This is ensured by enhancing extrinsic surface characteristics of the component material through precision-surface treatment. For Surface Treatment, the facility has developed 23 different types of capabilities including: Titanium Anodizing, Chemical Passivation, Chemical Phosphatisation and Oxidation, Chromatisation, Copper Plating, Zinc Plating on Steel, Organic Coating, Hard Ultrasonic Cleaning, Vapour Degreasing, and Painting. Since the facility specialises in precision components and assemblies, the typical bath size is 700 X 800 X 500 mm.

PMSC is capable of integration of electromechanical and mechanical assemblies such as precision actuation systems for aerodynamic corrections of missile trajectory through servo-control of active surfaces. The facility is equipped with a Class 10,000 clean room of 145 sq.m. where parts/sub-assemblies arrive from different locations to be integrated into finished products. The product-specific integration lines/stations are equipped with customised assembly fixtures and necessary tooling and gauges. The in-process and post assembly dimension control and functional checks are also carried out on the same lines/stations. The temperature of the clean room is maintained at 18 to 20°C and RH range of 55% to 60%. This is essential for the precision assembly and integration of supercritical flight worthy hardware.

The type of aerospace components PMSC manufactures are function critical and therefore the general inspection and testing procedures, techniques and methods used in serial production industries cannot be applied in serial production of aerospace products as in case of say, automotive systems. This means that every single component manufactured at PMSC is tested and established for quality and documented without exception. Also high mission-criticality of all aerospace parts/sub-assemblies/products calls for 100% traceability. To this end, rigorous testing and inspection forms a key part of the activities and stage inspection checks, build tests and functional checks are carried out on every item produced. Randomly selected products undergo complete qualification and destructive tests to confirm process adherence. In light of all this it is only fitting that PMSC qualifies to the Aerospace production system AS 9100 C and also NADCAP certification for the special processes.

 'Build' checks and 'Qualification' through periodic destructive burst tests are carried out in a purpose-built armoured room where pneumatic tests up to 700 bar and hydraulic test up to 1750 bar are performed regularly. Such tests are performed remotely and monitored using remote cameras and controlled through quick response systems through operator's consoles. At the other end of the spectrum, PMF also has the capability and facilities for helium leak test (min leakage detectable limit being 4x10-10 m bar lit/sec).

A NABL-accredited material test lab, an integral part of the plant, is equipped with physical and chemical testing and calibration / analysis equipment. The NDT facilities include radiography, ultrasonic testing, dye penetrant tests, MPI, Eddy current and helium leak detection tests. 

Having put in place and stabilised a rigours testing and inspection methodology across its manufacturing systems, the focus at PMSC has lately been shifting to process quality monitoring from the earlier product quality monitoring so as to assure dynamic business requirements.

This process improvement philosophy is gradually extending to its dedicated supply chain as well. As part of implementing TOC, Strategy & Tactics (S&T) formulation PMSC identified three key focus areas viz., Availability of all (right) parts; Conversion of parts to full kits; and Maximising flow through production lines implementing the basic principles of Dr Eli Goldratt's TOC philosophy .

To synchronize the flow dynamics across, periodic raw material receipts, the rate of component manufacturing and supplies from partners' production lines and customers' fluctuating demands, it is essential to seamlessly connect the entire chain in one flow loop. To achieve this PMSC developed a customised Flow Management tool viz. Symphony, to integrate the complete supply chain, internal as well as external. The availability of the parts is ensured through a “vendor-based Inventory Management module" in which the parts suppliers connect to PMSC's warehouse virtually to see the inventory level at the stores and replenish stocks according to the dynamically buffered inventory levels suiting customer schedules.

Additionally, it has entered into strategic in-sourcing partnerships for non-core but critical operations/services like component manufacturing, NDT, warehousing & logistics, and estate management. This helps in having a continuous feed to the production line and unlocks the capacity for core and critical processes.

In the relatively short time that it has been operating, PMSC has contributed immensely to many of India's strategic defence initiatives and nuclear power programmes. From manufacturing and integrating the propulsion airframes for Akash, the medium-range, surface-to-air missile developed by DRDO to manufacturing the airframe structures and booster systems that power BrahMoS, world's fastest supersonic cruise missile to co-developing and producing major subsystems for MICA, the air-to-air missile acquired recently by the Indian Airforce from MBDA, the list is impressive. That's not all though. PMSC has also played a vital role in the manufacture of Barak 8 and MRSAM missiles through production of complex components such as seeker housing, weapon control systems and control system motor housing in serialised mode.

Laxmesh BH, Head of PMSC is very proud of all that the facility has been able to achieve since it first came into being. And for good reason – nearly everything that is manufactured in the shops of the facility today could not be produced earlier and simply had to be imported.

“Strategically, we aren't just an asset to L&T but to the country's larger defence agenda," he says. “We keep talking about being builders to the nation and putting the interests of the country above everything else and PMSC is a true manifestation of that philosophy."

Currently there exists no other private sector firm in India which can match the unique capabilities that PMSC offers, at least not under one roof. Its track record in catering to multi-technology programmes, end-to-end and take a product from concept stage to serial production in multiproduct environment and deliver, remains unmatched.

Comforting as that thought may be, Laxmesh BH isn't content and says that there's plenty more that remains to be done. “We don't produce a fully integrated missile yet. We're not integrating warheads or producing seeker systems or other critical electromechanical innards that go into making fully functional missiles. We would dearly like to develop for ourselves the ability to do that when the opportunity arrives."

His entrepreneurial genes and start-upesque makings of PMSC mean that he can hardly wait for the day when PMSC gets to do a complete missile, a full UAV or a launch vehicle. Fashioning subsystems is fine, but manufacturing and integrating missile systems from start to finish is where the real excitement as well as business opportunities lie.

For now though, it's all about preparing for that next phase of growth through learning and exploration and staying hungry, as he puts it.

The journey of PMSC began with no more than a whisper of an idea. That and a sort of belief which we normally associate with the early explorers who set out on ambitious journeys into the vast unknowns. Their only guide, a rare sort of surety which convinces them of the cause. Just like them, the mavericks at PMSC see the justness of theirs – to help the country grow self-reliant in the area of defence production.

Like the missiles it helps make, PMSC has locked on to its next target.​

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