New Renault Trucks range: seven years, 500 vehicles and 10 million kilometres of quality trials
In order to guarantee its customers the very highest levels of reliability, Renault Trucks has subjected its new range of vehicles to the most extensive and thorough series of tests in the company’s history. The new trucks have been developed using cutting-edge simulation techniques, test benches, and test tracks, followed by operational tests working for some fifty customers, all of whom had in fact been involved from the original specification stage right through to the very last real-life operational tests.
Reliability is not something that just happens – it evolves over long hours of testing and research. The new Renault Trucks range will not become a reality for the public until next June – but the quality control teams at Renault Trucks have been working on them day – and sometimes night! – for years.
The first hauls of the very first prototypes of this new range took place in 2008. “These early prototypes had been designed, tested and modified in collaboration with our customers and partners, who were involved every step of the way, from the very first drafting of the specifications,” explains Thierry Hours, vice-president responsible for renewal of Renault Trucks Construction and Long Distance lines. “This dialogue with our customers and the first hauls undertaken demonstrated that we had made the right choices,” he goes on. “Not just with respect to cab size and on-board equipment, but as regards the technologies we selected for the engines and bodies and the vehicles’ overall performance objectives.”
This first phase of development also included digital simulations, enabling calculations to be made concerning all the truck’s components according to how it will be used in both real-life and extreme situations. In line with the automobile world’s highest standards, these tools take simulation about as far as it can go, testing every aspect of the specifications. “Take the cabs for instance – thanks to the simulations we didn’t have to make cabin equipment prototypes, we just went straight to preproduction.”
All the data gathered during the simulations and initial road trials is then used by the Renault Trucks design offices, company suppliers and factory staff, to begin developing the manufacturing processes that will guarantee product quality. “For these new lines we’ve been conducting simultaneous engineering to an extent that had never been seen here before,” explains Thierry Hours. “All the departments involved, from design to AfterSales, worked together from start to finish.”
Gradually the exact specifications for every single one of the truck’s 6,500 parts are honed down. This stage of the design process involves making sure that both concept and design fulfil the intended purpose and meet quality requirements, and that the company has full command of the process required to produce them. Once all this has been verified, the tools needed to make them are designed and manufactured, and then, and only then, preproduction can begin. “Every stage of the process is really vital,” according to Thierry Hours. “It’s what determines how reliable the truck will be on the road and how well we master the production process in our factories. That’s why we are totally inflexible when it comes to the validation process.”
In 2010, the first completed vehicles, built using preproduction parts, emerged from the Bourg-en-Bresse site and were subjected to a variety of tests. “Our test methods are constantly changing,” says Thierry Hours. “To make sure we meet customer expectations as closely as possible, we visit them regularly upstream of the road tests to find out exactly how they use their vehicles, and then determine the most realistic tests and testing methods.” Most of the tests are conducted at the test centre in La Valbonne or on design office test benches.
First come the endurance tests on the test track. “In twenty weeks the vehicles undergo the equivalent of a year’s actual use,” Thierry Hours tells us. The vehicles are tested at the Renault Trucks test centre in La Valbonne. Some of the trials take place at 90 km/h on a speed circuit, while others are on tracks that simulate extreme conditions by deliberately deforming the cab or vehicle body significantly, so that the vehicle can be tested to the extreme under all conditions. If a part breaks, it is analysed, immediately modified and then the engineers test it again to ensure optimum quality for the final end product.
As for the reliability tests, their purpose is to subject every part of the vehicle to the customers’ typical patterns of use. Body, cab, and pneumatic and electric circuits are all tried and tested with respect to torsion and vibration on the test benches. The engines accumulate endurance hours on the test benches too, in every possible on-the-road situation. Life on board is not forgotten either, with tests that subject the doors and grille to misuse when being opened and closed.
All the electronic components are also put under strain on a specially designed bench that contains all the electronic functions inside the truck as well as those in the body and the engine.
Constant improvements are also made to the cab, which is tested on specially designed test benches as well. A cylinder system puts it into a series of extreme situations that test its solidity, shock absorption capacity, behaviour on the road and under difficult conditions, and longevity. In addition, for these vehicles Renault Trucks also conducted tests in a life-size wind tunnel, which helped engineers to optimise the trucks’ aerodynamics and rework some parts to improve the fluidity of air flows and thereby reduce fuel consumption.
In all, these test bench trials amount to the equivalent of over five million hours of tests on all the vehicle components: body, cab, engines, gear-boxes and electronic components. All functions are tested and the operations are repeated thousands of times so as to be absolutely certain that every component works properly and is totally reliable.
At the same time, the new trucks are driven on the open road, so that they can be tested under real-life conditions with respect to features like fuel consumption, road holding, noise and vibration levels, and life on board during the daytime and at night. A total of thirty two different features are measured to ensure product quality, performance and reliability.
Renault Trucks also carried out several series of tests under extreme conditions, and at high and low temperatures. The ‘extreme cold’ trials took place during three winters in Lapland, where temperatures regularly fall to -40°C. The ‘extreme heat’ trials were conducted during three summers in southern Spain or Oman, where temperatures regularly reach 45°C, and can hit 60°C in the sun. “During these trials, every aspect of the trucks is tested – road handling of course, how well they start after a really cold night, how they perform on seriously snow-covered roads or in thick dust – and life on board too,” explains Thierry Hours. “Our testers live and sleep in the vehicles, checking that the cab is sufficiently insulated, that the air-conditioning works properly, the heating, the demister, on board accessibility, even whether they can open the tool box when it’s extremely cold! The idea is to find themselves confronted with all the different kinds of situations our customers might have to deal with.”
To improve these tests even further and respond as quickly as possible to their findings, the design office has introduced a central data feedback system. Any incidents detected during the tests are entered into a data base and the design office then takes steps to solve the problem in real time, in collaboration with the test engineers, the production plant, and AfterSales, making any modifications necessary to resolve the issue. “By monitoring results in real time we can respond extremely quickly,” points out Thierry Hours. “The process was key to the successful completion of the tests for the new range.”
Once the development vehicles have been approved by the project team, the first preproduction models go into production and are handed over to partner customers for the final tests under real use conditions. Thus, in early 2012, Renault Trucks delivered some fifty vehicles from their Long Distance and Construction ranges to customers all over the world. “The panel covered all the applications our vehicles are used for, so we were able to test both long-distance regional and international haulage as well as heavy use construction vehicles carrying saw logs in Cameroon, or with 120 ton loads in Dubaï, or operating down Turkish mines,” says Thierry Hours.
Today, just a few weeks from the product launch, the vehicles are in the final phase of approval, with production set to begin in June. After 7 years of tests, 10 million kilometres, extreme conditions ranging from -40°C to +60°C, 300 test vehicles, 5 million hours of bench tests and feedback from 50 customers, the new Renault Trucks range is ready to be delivered to customers, and, in the words of Thierry Hours: “Their satisfaction will be the best possible reward.”