The launch of four configurations and two power nodes, 280 hp and 380 hp, marks the culmination of the first phase of Tata Motors’ World Truck development. The top end of 560 hp that MD Prakash Telang announced at the press launch will probably be introduced only in a later phase by 2012.
The engine that powers the 4028S 4×2 and 4928S 6×4 tractors and 3128T 8×4 cargo truck is the Cummins ISBe 270 derated somewhat to
266 hp @ 2500rpm and 970 Nm @ 1200–1600rpm. This 6.7-litre engine with single-piece head, four valves per cylinder, 1600 bar common-rail fuel system, and wastegate turbocharger, was first introduced in early 2005 at Euro 4.
It superseded Cummins’ 5.9-litre Euro 3 engine, which interestingly had been based on a platform developed by the European Engine Alliance (EEA) – the erstwhile three-way joint venture between Cummins, Iveco, and New Holland – using the design technology of Cummins’ legendary B-series engine. Since July 2008 the EEA is wholly owned by Fiat Powertrain Technologies (FPT), Tata’s other engine supplier for the World Truck.
For markets outside Europe, Cummins developed Euro 3 ratings of the 6.7-litre engine later in 2007 as part of its Worldwide Common Platform (WWCP) strategy, of which 270 hp/1020 Nm is the top of the slate presently available in India. Autocar Professional learns that Cummins is working on a few ratings lower down the scale.
The ISBe is the first fully electronic, common-rail-fuelled heavy duty engine to be series-produced in India, although the components are still mostly imported — for example the engine blocks and heads come from Brazil, and are only machined at Tata Cummins’ (TCL) plant in Jamshedpur. The fuel system hardware is from Bosch, and the electronic control module (ECM) and software from Cummins. TCL has a localisation target of 90 percent by 2012.
The 6.7-litre engine carries forward the performance and fuel-efficiency advantages for which the 5.9-litre Euro 3 ISBe was famous worldwide. (These were based purely on the high injection pressures of its common-rail injection system, Cummins India engineering vice-president Mike Lambert told Autocar Professional in an interview last year.) And like its predecessor, this engine delivers a fuel economy advantage at the vehicle level as well, because it is electronic and several useful features can be programmed into it.
“For example cruise control and road speed governing, which yield a big advantage in fuel economy at the vehicle level, can simply be activated inside the calibration. Moreover, the customer can do that when the truck gets to the end of the line. Using Cummins’ vehicle electronic programming system VEPS, customers can actually modify some parameters in the calibration of the electronic control module (ECM) to suit what they want for their vehicle applications,” Lambert said.
For TCL, marrying the ISBe to the vehicle was a challenging experience because this was the first time it was dealing with an electronic engine that can communicate with other electronically controlled systems on the vehicle and support onboard diagnostics. Cummins’ Interact (the ‘I’ in ISBe) electronic intelligence system enables “drive-by-wire” electronic throttle control and multiplexing, which both simplifies wiring and allows data signals to be carried through to the smart instrument cluster and driver controls.
The engine ECM accepts inputs from all powertrain components – electronic transmission (if available), ABS, and ASR (anti-slip regulation) – via a high-speed data link, and responds exactly to requested adjustments in torque or engine speed for gearchanging or wheelspin correction. The result is smoother and more fuel-efficient performance, lower emissions, and added protection against powertrain wear. In addition, sensors throughout the engine continually send data to the ECM for self-diagnosis and protection.
A regular laptop with Cummins InSite diagnostic software and a couple of special connectors are the only tools the service technician needs to download and analyse fault codes. But since electronics and the sophisticated common-rail fuel system are novelties in the industry in India, TCL has just launched a major campaign to train Tata Motors’ service technicians, having just completed a similar programme for its own.
The four-axle 3138 tipper and the 4938 semitrailer tractor displayed at the launch are powered by a 380 hp Chinese-built Cursor 9 engine from SAIC Fiat Powertrain Hongyan Co (SFH). This 8.7-litre six-cylinder inline engine with overhead camshaft, four valves per cylinder, Bosch common-rail fuel system, and Holset variable-geometry turbocharger, went into volume production at SFH, Fiat Powertrain Technologies’ joint venture in Chongqing, just one week before the launch of the World Truck.
Originally introduced by Iveco in Europe in 2006 as the C87 designed specifically for industrial and agricultural applications, the Cursor 9 (technical code name F2C E2681B*B) made its world on-highway debut only this March on the Genlyon range of trucks from SAIC Iveco Hongyan Commercial Vehicle Co (SIH) based on Iveco’s Stralis. Weighing in at 865 kg, the engine has been certified to Euro 3 and designed to be upgraded to Euro 4 and Euro 5 with no hardware modification.
In the SIH Genlyon the engine is presently available in two ratings of 270 hp and 400 hp @ 1800–2100rpm and 1300 Nm and 1600 Nm @ 1100–1800rpm, the lower rating with a fixed-geometry turbo. The customer buzz following the World Truck launch is that a 310 hp version is shortly going to be offered on a 40-tonne tractor.
The 380 hp/1500 Nm rating was developed for Tata in Bangalore by Bosch Ltd, whose solution to meet the OEM’s specifications for driveability in these two applications involved reducing the rail pressure to 1400 bar.
Tata’s original choice for this performance class was Cummins’ 160kg-lighter 8.9-litre ISLe, and the company’s presentation to the media did indeed specify a 370 hp/1550 Nm ISLe as optional on the 3138K and 4938S. The fact is, Cummins India had developed and begun productionising two Euro 3 ratings – 340 hp and 375 hp – of the Euro 4 WWCP generation of this engine in 2007, but the programme has been kept in limbo for over a year now after the Cursor 9 was inserted into the equation in what would appear to be part of a quid pro quo that opens up Iveco’s distribution and service networks in Latin America and Eastern Europe to Tata.
Autocar Professional learns that the next higher power node in the World Truck portfolio is 420 hp, originally planned around Cummins’ ISMe but now designated as “above 380 hp” and very likely to include FPT’s European Cursor 10 F3A at Euro 5 in 2015.
The 10.8-litre ISMe was the first heavy duty engine in its class designed for a life-to-overhaul of one million kilometres. Certified for Euro 3 and Euro 4 in a range of ratings, it is now built in China by Xi’an Cummins Engine Company, Cummins’ 50:50 joint venture with Shaanxi Automobile Group Co. The 420 hp Euro 3 version produces its peak output at 1900rpm and peak torque of 2010 Nm at 1200rpm. Also available are two Euro 4 ratings of 410 hp/2000 Nm and
440 hp/2080 Nm. The 10.3-litre Cursor 10, by contrast, is presently available in selective-catalytic-reduction-(SCR)-optimised Euro 4 and 5 ratings of 420 hp @ 1550–2100rpm and 1900 Nm @ 1050–1550rpm, and 450 hp/2100 Nm.
Starting from 150 hp, the range of power ratings extends all the way up to 560 hp, corresponding to the top available Euro 4 rating of FPT’s Cursor 13 F3B. This 12.9-litre inline six-cylinder engine with four valves per cylinder, Bosch EDC-controlled unit injectors, and variable-geometry turbo, delivers its peak output at 1600–1900rpm and 2500 Nm @ 1000–1575rpm. The Cummins alternative is the new 13-litre ISZ, developed and produced by Dongfeng Cummins Engine Co in Wuhan, and available (for the Chinese market) in ratings of up to 545 hp.
The development of heat exchangers that would manage the massive charge air and engine cooling requirements of these powerful engines was entrusted to Tata Toyo Radiator (TTR). The company responded with an aluminium radiator that has a thinner core and is both lighter and cheaper than conventional designs, directly contributing to improved fuel efficiency and reduced operating costs.
Besides, being thinner, it requires less coolant than the conventional designs, in which higher cooling demands are typically met by increasing the thickness of the core. Reducing the size of the radiator meant reducing the heat exchange surface, and hence the challenge was to get better efficiency from a smaller surface area.
“We achieved this by enhancing the geometry of the core for better heat exchange efficiency. Using our past experience, we simulated the actual conditions under which the entire system consisting of the radiator, intercooler (which we also developed), and various other components would be used, and optimised the design and configuration to arrive at this solution,” TTR’s Ravi Chidambar said.
Asked what his engineers’ main challenge was, the CEO of this joint venture between Tata AutoComp Systems, T.Rad Co of Japan (a major supplier of heat exchangers to Iveco and Hino), and Mitsubishi Corporation Nonferrous (supplier of aluminium to both Tata Toyo and T.Rad), cited Tata’s far more exacting durability targets for the World Truck compared to other vehicles for which they had developed radiators.
The emphasis was on commonisation to reduce costs, he pointed out. “Hence, while the radiator and intercooler will be the same across models, there will be minor changes in terms of tooling and customisation to suit each model.”
Tata’s orders for air intake systems, from air inlet to turbo inlet, have been split 50:50 between Fleetguard Filters (FFPL) and Mann + Hummel across all applications. Designing a system for BS4 and BS5 requirements was one peculiar challenge for Fleetguard, according to marketing head Tarun Dham. “Another was to develop aesthetic designs in plastics that would withstand extremes of temperature and still meet Tata’s stringent life requirements — after all, this was the first time our products would go on trucks exported around the world,” he said.
This 50:50 joint venture between Cummins Filtration and Pune-based Perfect Sealing Systems, has so far supplied Tata’s alpha and beta requirements from its Nandur plant near Pune, but production supplies will come from its Jamshedpur facility beginning September.
Cummins Filtration is the global leader in filtration, exhaust, coolant, and fuel additive technology for engine-powered systems of all kinds, and FFPL is the exclusive supplier of all the wet filtration products for the Cummins ISBe and ISMe on the World Truck. It is also in discussions to provide Fleetguard coolants as first fill.
Cummins Exhaust (CEIL), the 50:50 joint venture that Cummins Filtration had with Cummins India till recently, is Tata’s exclusive source for Euro-3-spec acoustic mufflers for the programme. It will supply these in six configurations including, for the first time in India, a vertical model for the 3138K.
Director Manoj Solanki told Autocar Professional last month that initial deliveries of 30–60 a month for the World Truck could rapidly grow to “10,000 next year, or even 20,000”, even as CEIL transitions into an entity that will be 100 percent owned by Cummins Emission Solutions (CES) ahead of the advent of BS4 emissions legislation in April 2010.
CES is the leader in emission solutions for medium and heavy duty on-highway truck manufacturers in the Euro 4 and 5 markets worldwide, ahead of other big names like Emcon, Tenneco, Cornaglia, and Eberspächer.
Wearing his CES shirt, so to speak, Solanki revealed that eight prototype SCR systems airfreighted in from China would be installed on test vehicles with Cummins engines by the first week of June. “Combining a CES system with a Cummins engine allows Tata Cummins (ISBe) or Cummins India (ISLe, ISMe) to tune the entire system, with the SCR aftertreatment controlled by the engine ECM,” he explained.
“For a non-Cummins engine the strategy is to have a separate dosing control unit, which links the SCR system to the ECM and allows CES to maintain control on the system and its performance. We’re trying to make it plug-and-play, because in these situations our interactions will be limited by the ECM.”
While the mufflers are supplied from CEIL’s Daman facility, the SCR systems will initially be imported from China, where CES started producing them this April. “However, if we see the volumes for SCR going up suddenly, we may advance our plans to set up manufacturing here,” Solanki said, adding that this would be at Cummins’ megasite at Phaltan near Pune.
The Cummins ISBe is mated to the ZF Ecomid 9S1110 OD gearbox or Tata’s own G1400, while Eaton has been contracted to supply its Fuller transmissions for the Cursor 9 and higher-powered engine applications. The latter presently has three nine-speed transmissions on the World Truck — the FS 10309 and FSO 10309 (overdrive), and the FS 15409, a variant of the 10309 specially developed for the heavy tipper.
Interestingly, while ZF is initially importing its transmission from a plant in France, it is expected to localise the design with gears sourced from Ashok Leyland and housings sourced from Jaya Hind, sister company of MAN Force Trucks, its other erstwhile licensee for this model.
For Eaton, the application approval process it used on the World Truck programme is standard practice worldwide for new truck developments but unique in the Indian context in that it directly captures the “voice of the customer” and clearly elicits the requirements in terms of application, terrain, duty cycle, GVW, startability, and gradeability in maximum detail at the earliest stage of engagement with the OEM.
“The OEM’s marketing and engineering organisations fill out an application approval form, which Eaton uses to search its database for the available transmissions that best fit the application. We then present these options to the OEM, and then sit and discuss with them the pluses and minuses of each. Of course, we also suggest ways to compensate for those minuses by means of changing the axle ratio, tyre size, driveline angle, etc. We’ve had this discussion for each vehicle configuration,” Pavan Pattada, India head of Eaton’s Truck Group, explained to Autocar Professional.
The result of this process so far has been the selection of the 10309 model for the 4038S and 4938S, on the one hand, and the 3138K on the other, despite the contrasting requirements of these applications. The difference, he explains, is in the choice of the overdrive version for the tractors, and the development of a new direct-drive variant designated 15409 for the tipper, in which the lower gears have been strengthened because the vehicle will be operated for longer periods in those gears.
“As part of the application approval we studied the duty cycle, i.e. the number of hours the vehicle is going to be operated in each gear. We had the option of either looking for a different product, or working on an existing family to meet the requirements. Together with Tata, we decided to do the latter,” Pattada said.
With a torque capacity of 1750 Nm the single-countershaft 10309, presently imported from Poland, could still fit into some applications above 380 hp, though Tata and Eaton are now applicating Roadranger 10- and 13-speed twin-countershaft models for off-highway applications using the 420 hp Cummins ISMe. Eaton displayed its 10-speed RTO 16910B-DM3 transmission at last year’s Auto Expo and a variant of this could very well be out on the roads in a year.
Eaton is the only independent supplier worldwide of this extremely robust design, which is used both on- and off-highway. “In Brazil the European players often choose the twin-countershaft solution over their own in-house models for severe-service applications,” Pattada pointed out. In line with the company’s worldwide manufacturing strategy the transmissions will initially be imported from China, where they are assembled from parts supplied out of Eaton plants in Brazil, Poland, China, and India, and then progressively localised as volumes pick up.
The next critical link in the driveline – the propeller shaft – comes from Spicer India and the RSB Group. While Spicer is contracted to supply “approximately 25” designs with varying torque capacities for the full spectrum of applications, RSB has developed six designs for five World Truck models in the 31-, 40-, and 49-tonne classes that it will begin supplying as soon as these models go into commercial production.
Among the technical highlights of the Spicer products that chief operating officer B D Singh points out are their “lubed-for-life” service-free joints, low NVH, and increased torque capacity at reduced component weight resulting in lower axial forces on the slip joints and increased durability compared to the shafts it supplies for Tata’s legacy truck models.
“Tata’s requirement was that the durability and performance of the shafts under Indian vehicle utilisation conditions be enhanced — in particular, they needed highly statically and dynamically balanced shafts for high-speed applications and improved corrosion-resistance,” he explained.
Meeting these expectations was a challenge for Spicer’s engineers, not least because of the number of design iterations they had to perform without falling behind on Tata’s strict sample and supply timeline. But Singh is proud of the end result: “All vehicle validations so far have qualified the customer’s expectations,” he told Autocar Professional.
The RSB shafts are based on designs developed by its technology partner Eugen Klein GmbH in Esslingen, Germany. “Models similar to the ones we have developed are already in use in similar applications abroad. Our new shafts are both lighter and cheaper for the same transferrable torque,” GM (corporate strategy) Rajnikant Behera said. He cited face serrated mountings, Rilsan-coated sliders with metallic dust covers, and sealed universal joints as the salient features of his company’s products.
Axle partner Meritor HVS India is gearing up to supply its MS14-160 hypoid axle, which Tata is expected to fit on the 3128T 8×2 cargo truck going by the fact that it is already used by MAN Force on its 4×2 and 6×2 rigid trucks for the domestic and export markets. An 18-inch crown wheel, the largest on the market, and other design enhancements give this model a 30 percent higher torque capacity than MHVSIL’s other available axle in this load class, the MS14-1495. According to vice-president S Raghunathan a tandem version, the MT28-160, will also be available to Tata.
Another Meritor axle the OEM is presently testing for the World Truck is the two-speed MS-240 for 4×2 tractors and 6×2 and 8×2 rigids. A design that has already been proved in Brazil and Mexico for over seven years now, this axle has a planetary gear reduction built into the differential itself, adjacent to the crown wheel. By means of an electropneumatic control the driver can either engage the regular ratio or step the propshaft input down through the reduction.
“Typically you can operate in power mode when, for instance, you’re negotiating a steep gradient, and then switch to economy mode when you’re at grade. This improves the flexibility of usage and yields better fuel efficiency and operating economics,” Raghunathan told Autocar
Professional in an interview a few months ago. So even though this axle is more expensive, he is convinced the market will absorb the additional cost without fuss because the value it offers is “readily realisable in terms of fuel efficiency, starting from day one”.
CHASSIS
The six-rod inverted bogie suspensions for the tandem rear axles on the 49-tonne tractors and 31-tonne tipper and cargo truck were indigenously designed and 100 percent localised by TACO Hendrickson Suspensions (THSL) in Pune to meet Tata’s demanding cost targets.
Suitable for a wide variety of multiaxle applications, this design improves the vehicle’s stability and braking performance. Other crucial advantages over current systems, particularly in Indian operating conditions, include ease of serviceability and better ride quality (a function of the rubber bolsters at the spring ends, which also act as effective rebound stoppers).
The first of its kind in India, the 48-tonne suspension on the 3138K is THSL’s heaviest-duty model. A lighter 26 tonne (plus 15 percent overload capacity) version is available on the 4938S and 4928S, and the 3128T offers the additional options of a regular 26-tonne model
or a 19-tonne-plus-30-percent.
The front axles on all models are suspended by means of parabolic leaf springs, believed to be from a Korean supplier even though, interestingly, THSL’s parent company Hendrickson International is the world leader
in this type of springs.
Parabolic springs deliver far superior ride characteristics to the conventional multileaf variety, and will continue to be used on the front axles even when air suspensions from THSL make their appearance on the World Truck as early as next year for export models. “Although air suspensions on front and rear axles are ideal, OEMs even in Europe save costs by matching the frequencies of the parabolic front suspension with those of the rear air-ride system,” an Autocar Professional source said.
The twin-steer systems on the 3138K and 3128T are variants of the Servocom 8099 twin-circuit power steering gears from ZF Lenksysteme GmbH. For single-steer applications with lighter front axle loads such as tractors that will be used for long-distance haulage, tip-trailers, bulkers, and reefers, Tata has chosen TRW Automotive’s latest THP-series from Europe rated at 175 bar. This is the same series presently used in the USA, Brazil, and Europe, which Rane TRW Steering Systems in Chennai has adapted for India.
The superior features of the TRW system include faster steering ratios for improved lock-to-lock turns compared to existing gear designs, lower internal gear friction for better return-to-centre response, and a reduced package size for increased wheel cut, according to P B Rajan, GM (marketing) of Rane TRW Steering Systems in Chennai.
“This model delivers the highest torque per unit weight in the world,” he told Autocar Professional. “It has automatic poppets and advanced rotary valves for user comfort and provides power assistance from lock to lock even while the vehicle is stationary.”
Rajan cited the tight lead time for submission of special prototype parts and Tata’s stiff cost targets as specific challenges his engineers faced in developing this product.
The air brake systems for truck and trailer come from Knorr-Bremse and WABCO, the two leading suppliers worldwide. The former’s scope of supply includes the air processing unit (APU), foundation brakes and actuators, trailer brake system, and ABS for truck and trailer.
The Knorr system is designed for a brake circuit pressure of 10 bar, as against the 8.1 bar systems that go onto Tata’s existing range. It is able to deliver higher braking torques at the wheel ends using similar-sized, albeit more robust and reliable, actuators that have actually been validated at pressures of above 10 bar, according to sales, marketing, and business development head Anirban Mukherjee.
The APU ensures better air management, higher reliability, and longer service life than the traditional air dryer by integrating this function with an oil separator and multicircuit protection valve into a single unit. Interestingly, it constitutes the mechanical basis for one of Knorr’s most recent innovations: the EAC electronic air control system.
The EAC combines the functions of the APU with electronics that intelligently reduce compressor fuel consumption unlike conventional air processing systems that operate independently of the drive situation. Measurements on various European road circuits have indicated potential fuel savings of several hundred litres per year using EAC, for which Knorr sees possibilities on Tata’s export models in the next couple of years.
Knorr’s 325mm S-cam drum brake has already been validated by Tata and it is awaiting approval for samples of a 410mm version it has supplied, though the foundation brakes on the front and rear axles on the launch vehicles were from Meritor HVS India associate KTMS and the TVS Group’s Brakes India respectively.
Having already developed and begun exporting disc brake components, it is now working with Tata on disc brakes that will be introduced on the World Truck in the next two years.
Concurrently, Autocar Professional learns, Knorr has kicked off the exercise of designing the first EBS electronic braking system, which should be ready for testing and validation in the next six months for a Tata vehicle that will only be rolled out in 2012.
For the first time in India the hand brake valve has been designed with a trailer check function that senses when a trailer is coupled to the towing vehicle and automatically applies the trailer brakes as well. In fact Knorr has also developed separate brake systems with ABS for the two- and three-axle semitrailers from Tata International DLT that Tata Motors will offer with its tractors, and for centre-axle drawbar trailers that the OEM is also planning to introduce later.
An interesting safety feature of this system is the park/shunt valve on the trailer, which is used to activate the spring brake when the trailer is uncoupled from the tractor. This parking brake cannot be released unless the trailer is once again coupled to a tractor and there is pressure in the palm coupling.
Every World Truck that Tata produces will roll out on steel wheels from Kalyani Hayes Lemmerz (KHL) in Pune. MD Prakash Kodlikeri reckons that Tata will first market the World Truck in non-European countries just to establish the product. “In such a case Tata’s decision to go in for 20-inch rims is appropriate. In fact we already supply these wheels to Daimler, Volvo, and Iveco in Europe,” he told Autocar Professional.
KHL had the wheels for the World Truck specially tested at its parent Hayes Lemmerz International’s European test facility in Germany. For the heavy duty tippers and construction vehicles, it will shortly begin supplying 24-inch wheels homologated for and approved by Tata Motors for this application. KHL is already the sole supplier of these wheels to Volvo India for the FM400 and Mercedes-Benz India for the Actros, and exports large numbers of this type to Europe, Africa, and Southeast Asia.
As for the peculiar challenges KHL faced designing and manufacturing the wheels for this project, Kodlikeri singled out the mining area in particular, which he said poses lots of challenges that need to be taken account of while designing the wheels for this application. For one there are practically no normal roads, and the vehicles in these areas are often very heavily overloaded, because of which the maintenance of the tyre/wheel assembly in such areas needs special consideration.
“Before we designed this wheel, our engineers spent lot of time in the mines to understand the product application. I must say that our wheels last for more than 10 years in such areas and are performing very satisfactorily, not only in India but also outside the country.”
Interestingly, the World Truck models produced at the Tata Daewoo plant in Gunsan, Korea, will also roll on KHL wheels, he pointed out: “We initially supplied Daewoo, and then Tata Daewoo, from our plant in Pune.”
The high-performance wheel-ends from SKF on the front axles of the 4028 and 4928 tractors each consist of two optimised premium tapered-roller bearings (TRBs), two premium hub seals developed by SKF Sealing Solutions, Bangalore, and high-temperature lithium-based grease for increased regreasing intervals.
SKF India is the sole supplier of the front wheel end for these applications, and also developed the kingpin seal especially for the World Truck. “As a part of our drive towards sustainability and environment-friendly products and solutions, we have supported a unitised bearing for the first time in an application like the steering link to omit grease leakage and spillover in the vehicle and into the environment. This solution will be launched on the tipper series in September,” Ranjan Kar, director of SKF India’s automotive business unit, revealed to Autocar Professional.
In addition, the company supported HV Axles on the prototype development of its HR210 hub reduction axle with a wheel-end TRB, a pinion-class TRB, and a deep-groove ball bearing for the tandem version. It is also one of the suppliers of TRBs for the differential.
The JSK36DV1, and JSK38DV50 and JSK38C1, fifth wheel couplers on the 40- and 49-tonne tractors respectively are from Jost India Auto Components, Tata’s exclusive supplier of this critical device that connects truck to trailer. Designed for an imposed load of 20 tonnes the JSK36, with a two-inch kingpin, is the most widely used fifth wheel model in the Asian market and one of Jost’s largest-selling worldwide.
The JSK38DV50 is a pressed version of the JSK38C1 cast fifth wheel for an imposed load of 28 tonnes that Tata has so far used on its existing 4923 model. “Since the Indian market traditionally prefers the pressed version, this development was undertaken for cost-optimisation,” G S Pradeep, senior sales and marketing manager for Jost India, explained.
“It costs about 30 percent less, and has passed all the standard life tests required to ensure reliability. More importantly it is reworkable, which is a vital requirement in the Indian market. While the cast version is extremely strong, it could possibly crack under the extreme abuse to which fifth wheels are subjected here and cannot be welded or bent back into shape in the event,” he pointed out.
According to Pradeep, the JSK38C1 2J on one of the 4938 tractors displayed could be an option on the World Truck for export markets, where the weight limits of semitrailer combinations are seldom exceeded and cast fifth wheels are usually preferred.
An important feature of this model is the interchangeable locking mechanism
that can accommodate both, two-inch and 3.5-inch kingpins, allowing the operator
to switch the rated imposed load on the coupler to the maximum 36 tonnes for
which the JSK38 platform was originally designed.
INTERIORS
Grupo Antolin Pune is Tata’s exclusive source for soft trim parts, i.e., the headliners and fabric trims for the doors, sides, and rear of the cab. For this company, which is supplying “more than 20” part numbers from its Ranjangaon plant near Pune, the World Truck was a significant challenge because it was now dealing with parts of “huge truck” proportions, according to GM (marketing) Ajay Apte.
“For the first time an Indian truck was being developed with a trim level that compared to those sold in Europe. For us, maintaining tolerances and fit and finish across such large dimensions was a herculean task,” he reminisced. GA Pune supplies headliners with integrated lamp bezels, speaker grills, and air vents, which will be added on at a small subassembly warehouse the company is setting up in Jamshedpur preparatory to the commercial launch of the trucks.
Also for the first time in the world, the company developed a special solution for the side trims using knitted fabrics treated with 3M Scotchguard to ensure cleanability, Apte pointed out. “GA uses a different, more expensive material in Spain. For India we had to come out with a cost-effective solution based on the same basic sandwich.”
The high-end air-sprung or mechanically suspended driver and co-driver seats with integrated seat belts are a first on a truck in India. Designed and developed in Germany by Isringhausen GmbH, the world leader in driver’s seats for trucks, in a joint venture with Tata Johnson Controls Automotive (TJC), they have gone into limited production at a TJC facility in Pune till ISRI-TJC’s plant in Jamshedpur is set up.
The seat squabs can be adjusted for height, fore and aft movement, and tilt; adjustable lower and upper lumbar supports and high-density foam and bolsters make for additional comfort. The seats are optionally fitted with a heater to provide comfort in extreme cold conditions.
“The World Truck was conceived with a seating system of global standards with respect to safety and comfort. The challenge was to design the seats keeping Indian road conditions in mind. That took an intensive R&D effort, following a global benchmarking exercise we did on truck seating systems,” CEO Vinayak Lingayat said.
The result is seats that not only meet the stringent ECE norms concerning ergonomics and occupational safety but also conform to AIS regulations. A lot of effort has been made to localise the design, but certain critical components will continue to be imported from Germany, he added.
The complete wiring harness that Tata Yazaki Autocomp (TYA) designed and supplies for the World Truck compares to that on any premium European truck, marketing head Prashant Gajendragadkar told Autocar Professional.
“The bus bar design drastically reduces the size of the wire bundle coming into the fuse box for ease of handling, assembly, and maintenance. A single connection joins all vehicle applications to the battery power through the bus, and individual functions are activated by insertion of a simple fuse. This sleek new concept has helped reduce 75 circuits and liberates a large space for other aggregates,” he said.
That wasn’t all: a special bulkhead was designed as an interconnector between the engine cabling and the dashboard wiring harness. This not only ensures ease of fitment on the vehicle but also enhances serviceability.
The routing of the harness on the vehicle was developed with 60 different clamping options. The complete design also involved preparing the circuit schematic and the fusing and earthing strategy, and situating the bulkhead so that the cabin and engine compartment connections could have a common interface point with the unique fuse box to suit all models in the World Truck programme.
At the moment there are 11 distinct variants of the electrical system for the right-hand-drive vehicles that will be sold in India, seven of them in L1 (low-end) and L2 (high-end) versions, he revealed. Each of these will operate on the same bulkhead and fuse box design.
“In LHD vehicles meant for export the bulkhead will simply be a mirror image of the present design, while the fuse box will remain the same. By this commonisation TYA has been successful in dramatically reducing the variety and thereby saving on resources like costs and time,” he added.
The intelligent electronic instrument
cluster from Continental Automotive Components India was developed at Continental Automotive R&D locations in Germany and Romania. It is the first of its kind with contemporary European features to feature on a commercial vehicle in India.
The cluster evaluates digital and analog inputs from various sensors fed to it via a CAN bus that also networks the electronic control units around the vehicle. Using this information it calculates current driving and vehicle parameters, such as fuel consumption, which it then displays either on the analog gauges (driven by high-precision electronic stepper motors), or as warning symbols (illuminated by LEDs), audible alerts, or as average mileage or “distance to empty” data on the TFT LCD panel in the centre.
In addition, error messages received from various ECUs are displayed in the menu in English and Hindi. This keeps the driver informed about the state of the vehicle so that he can act accordingly. The cluster also stores error information in itself, which can be downloaded at the service station later by service personnel using diagnostic tools.
According to GM (commercial vehicle) Hemal Shah, the low awareness of, and appreciation for, the technical sophistication of the product in the Indian truck market made the project particularly demanding.
“The technical specifications have evolved since we first started in 2006. It was particularly difficult adapting a system architecture predominant in Europe and other developed countries to the Indian market even as the system requirements were continuously being upgraded in the last 2½ years, and called for an intensive R&D effort. But we finally achieved it in cooperation with Tata’s Engineering Research Centre,” he said.
The cluster’s scalable architecture allows Tata to meet future demands for communication with tachographs and integrated telematics. Shah told Autocar Professional that Continental would supply tachographs for the World Truck in a later phase of market penetration. “Continental is the world leader in tachographs with a more than 95 percent share of the market,” he said. Other prospects are body control modules (BCMs), supplied solely by Bosch for now, and sensors.
The electronic throttle control pedal is a WM542 model from Williams Controls, the world’s leading manufacturer of such pedals and the dominant supplier for BS3 truck programmes in India with an 80 percent share. This all-plastic suspended pedal uses a non-contact sensor that provides an electrical signal to the ECM in response to the driver’s demand for engine power.
While the pedal is already fully compatible with the Cummins and Iveco engines on the World Truck, Shailendra Goswami, CMD of Williams’s India representative Pushkaraj Engineering Enterprises, says it can easily be adapted for any engine or application requirement by simply programming the sensor according to the configuration of the ECM. This is done either by Williams Controls itself, or by the supplier of the ECM if the latter insists on being proprietary about its load circuit diagrams.
For brake and clutch actuation, Tata has chosen an integrated pedal unit (IPU) from Knorr-Bremse in keeping with its modularisation strategy. This assembly saves space in the footwell by integrating the respective pedals with the foot brake valve, clutch master cylinder, and brake light switch in a single aluminium die-cast support structure.