Seven years and 10 million km 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 June – but the quality control teams at Renault Trucks have been working on them 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 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.
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.”
First come the endurance tests on the test track. 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.
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.
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. 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 after-sales, making any modifications necessary to resolve the issue.
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.
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.”