Responsibility means commitment. Mercedes-Benz has driven forward safety in coaches like no other manufacturer. And this of course goes for the Mercedes-Benz Tourrider as well. A stringent crash test was carried out especially for entry into the North American market.

The Mercedes-Benz Tourrider had to complete numerous tests before the start of production. It is one of the few buses in the world that has undergone a crash test. In conversation with Omnibus Magazine, project leader Orhan Dönmez, test engineer Peter Schmutz and exterior team leader Recep Karakis look back on the Tourrider's development phase and report on how the crash test went and what insights were gained from it.

Nobody knows the Mercedes-Benz Tourrider better than Orhan Dönmez. As project leader, he managed the development and testing of the coach model for the North-American market – from drawing up the specifications to mass producing the first exemplars. Asked about the biggest challenges during the roughly four-year project phase, the experienced engineer quickly turns to one event that took place almost at the end of the development phase: a front-on crash test at 15 mph into a sold concrete wall.

“Carrying out real-life crash tests is not required in either Europe or the USA,” Dönmez explains. “Daimler Buses is one of the few manufacturers in the world which nevertheless carries out voluntary crash tests on new designs such as the Mercedes-Benz Tourrider. We want to ensure maximum safety for driver and passengers, and therefore used the Tourrider crash test to verify our simulations in real life.”

In Neumünster, north of Hamburg, Germany, is one of the few crash test centers in Europe that specializes in commercial vehicles. Here, on the crash-test strip run by DEKRA Automobil GmbH, the Mercedes-Benz Tourrider is to be subjected to a head-on collision with a solid barrier with 100% coverage – that is, the entire front of the vehicle will be impacted by the collision.

Unlike cars, there are no set legal regulations for bus and coach crash tests. Because of this, the developers at Daimler Buses have long set their own criteria and parameters for these processes. An example of this is the crash speed: Hitting a solid concrete wall at 15 mph corresponds to a real-life situation where the driver is able to decelerate from ordinary driving speed, but is unable to fully prevent the collision.

Before the crash, days of preparation are needed. After all, there is only one chance to carry out the test – it has to go right. Installing sensors, orienting the cameras, rigoursly testing the flawless functioning of the cable pull that will accelerate the test vehicle, placing the crash dummy on the driver’s seat at the exact right angle and fixing its hands to the steering wheel: The DEKRA specialists have their hands full.

“High-speed cameras record what happens in the passenger compartment and on the exterior of the coach in super-slow motion,” Orhan Dönmez reports. Special sensors measure the acceleration acting on the driver and passengers. The values measured by the crash test dummy’s sensors provide additional findings regarding the potential for injury to the driver in such a full-frontal collision.

The results provided by various crash sensors, distributed over the entire length of the vehicle, show that massive forces act on the bus, driver and passengers during a crash – even at a speed of 15 mph.

As expected, the highest forces arise just milliseconds after impact in the front of the vehicle, where the driver’s cockpit is located. To account for this, Daimler Buses has fitted the Tourrider with the Front Collision Guard safety system. In a crash, a stiff substructure to which the driver’s seat is attached can purposefully move backwards. The goal is to give the driver the space needed for survival. The kinetic energy is taken up by impact absorbing structures in and behind the bumpers and in the substructure.

The measurements prove it: despite the heavy impact, the sensors measure acceleration in the crash test dummy far below the threshold. The images from the high-speed cameras also show that the three-point seatbelt fulfils its task perfectly. It reliably holds back the dummy’s body, preventing impact with the steering wheel or dashboard.

Test engineer Peter Schmutz seems very pleased with the results of the crash test. “The evaluation of the data confirms what our simulations have already suggested: Based on our evaluations we can state that the Front Collision Guard is very likely to make a decisive contribution to protecting the driver in the case of a full-frontal collision. Barely any damage could be found in the passenger compartment.” Thus, the Tourrider shows itself to be a true Mercedes-Benz – not just in its comfort and driving power, but also where safety is concerned.