Passive safety: One star is all you need

Jul 15, 2014
In terms of passive safety the new C-Class Estate sets new standards in its segment.
In the development of the new C-Class Saloon and Estate in-house test requirements and test criteria for crash testing were applied that go beyond legal and rating requirements. Knowledge gained by Mercedes-Benz Accident Research was furthermore taken as a basis. Mercedes-Benz not only looks to vehicle ratings such as Euro NCAP, but also takes into account what actually happens in accidents, resulting in "real-life safety".
Just like the Saloon, the new C-Class Estate also achieves very good results with legal and rating tests. The basis for this is the intelligently designed bodyshell with its particularly rigid passenger compartment. The front end structure, floorpan, side wall and rear end were designed for high structural safety with regard to geometry, joining techniques and material quality. Contributing factors include:
  • A high-strength passenger compartment made of high-strength and ultra-high-strength steel and sheet metal with graduated wall thickness
  • A bodyshell structure whose front and rear can absorb energy with purposeful deformations
  • A large deformation zone of the front due to a subframe that absorbs additional energy in an accident
  • Several parallel load paths for improved load distribution in partial frontal collision (offset crash)
  • A steering column that can deform telescopically in a frontal collision
  • An extruded aluminium profile cockpit cross-member between the A-pillars
  • Doors with reinforcement profile made out of aluminium
  • A main floor with massive tunnel reinforcement and now continuous floor side members
Airbags and head restraints for safety
Three-point seat belts with pyrotechnical belt tensioners and belt force limiters are installed for driver, front passenger and passengers on the outer rear seats. In the PRE-SAFE® phase belt tensioning is electronically controlled and reversible. The centre seat of the second row is equipped with a standard 3‑point belt system. A rear seat-belt status display in the instrument cluster informs the driver whether the passengers in the back have fastened their seat belts.
ISOFIX child seat anchorage points on the outer rear seats ensure safe attachment of appropriate child seats with additional anchorage points at the top of the rear seat backrest.
In addition, a host of airbags provides occupant protection in an accident. For example:
  • An optimised windowbag in the area of the roof between the A, B and C-pillars for the head area of driver, front passenger and passengers in the outer rear seats.
  • Combined thorax/pelvis sidebags for driver and front passenger, which are able to provide additional protection in the event of a side impact. Optional sidebags for the outer rear seats.
  • Kneebag for the driver to protect the knees and stabilise the upper body, which positively influences occupant movement in an accident.
  • Adaptive airbags for driver and front passenger with two-stage staggered deployment, depending on the detected severity of the impact and seat position.
Intelligent front passenger airbag
The front passenger seat is fitted with automatic child seat recognition, which dispenses with the existing transponder and instead works with a weight mat. This enables any child seat to be used. The airbag is automatically deactivated in this case and reactivated once the child seat has been removed if somebody again occupies the front passenger seat. Unlike systems offered by competitors, which often use a key switch to deactivate the airbag, this system prevents the user from operating the airbag incorrectly. Users often forget to manually activate the front passenger airbag when removing the child seat. In the event of an accident this can place adult occupants in considerable danger since the front passenger airbag and the seat belts work in tandem and can only achieve the necessary protective effect for adults by operating together.
New head restraints for driver and front passenger provide early support for the head in the event of a rear impact and thus are able to reduce the risk of whiplash injuries.
Systematic pedestrian protection
The following measures are implemented for pedestrian protection:
  • Active bonnet, which is moved upwards by approximately 80 mm when an impact is detected, thus creating additional deformation space during the impact. The bonnet can be locked again afterwards to drive to the nearest workshop, for example. After having been triggered, the pyrotechnical actuators must be replaced. The pyrotechnical actuators are lighter and more compact than reversible actuators.
  • BAS PLUS with Cross-Traffic Assist and PRE-SAFE® Brake alert the driver, provide braking assistance and trigger, if necessary, autonomous braking when the system detects a pedestrian in the danger zone and the driver does not react to the system's warnings. This pedestrian detection, in conjunction with the optionally available Driving Assistance package Plus, represents a milestone in preventing accidents with pedestrians and/or reducing their consequences.
In the event of an accident
After an accident has occurred, various measures dependent on accident type and severity can mitigate the consequences and make fast rescue possible. These include:
  • Automatic interruption of the fuel supply can prevent leaking fuel and fires.
  • Engine emergency shut-off can prevent the risks of fire and prevent the vehicle from moving inadvertently.
  • Deactivation of the 12V starter motor circuit minimises the risk of electrical shorts in the engine compartment in serious accidents and thus the risk of fire.
  • Deactivation of the high-voltage system ensures the electrical safety of rescuers and vehicle occupants after an accident.
  • Automatic door-lock release can help the occupants get out of the vehicle on their own or facilitate their rescue.
  • The windows are partially opened automatically to ventilate the interior - for example, in the event of smoke build-up from the pyrotechnics of the airbags.
  • The hazard warning lights are activated to warn other road users.
  • Crash-responsive emergency lighting is activated, improves orientation in the vehicle, and can make it easier for the rescuers to locate the vehicle.
  • Crash gaps integrated between the wings and the doors can make it easier to open the doors after a frontal collision.
  • The electrically adjustable steering column automatically rises and can thus make rescuing the driver easier.
Mercedes-Benz emergency call for fastest possible aid
The new Mercedes connect me system is celebrating its premiere in the C-Class Estate. Supported functions include the Mercedes-Benz emergency call. The emergency call can be made automatically or manually. It is automatically triggered if at least one airbag in the vehicle deployed. The service centre then establishes voice communication with the vehicle. If there is no response, it immediately alerts the nearest rescue service.
Guidelines for Rescue Services with important information for rescuers
To enable rescuers to work quickly and safely, Mercedes-Benz provides a rescue card for the C-Class in various languages that can be downloaded for free. The C-Class is furthermore equipped with QR code stickers – a small but effective innovation with which Mercedes-Benz makes rescuing accident victims faster and safer. The QR code can be read with smartphones and tablet computers and sends a rescue card for the vehicle model to the display of the rescuers. This card contains all the information needed to rescue casualties quickly.
Mercedes-Benz C-Class Estate (S 205) 2014, driver assistance systems, BAS PLUS with Cross-Traffic Assist (german version)
Mercedes-Benz C-Class Estate (S 205) 2014, driver assistance systems, BAS PLUS and PRE-SAFE Brake (german version)
Mercedes-Benz C-Class Estate (S 205) 2014, driver assistance systems, COLLISION PREVENTION ASSIST-PLUS (german version)
Mercedes-Benz C-Class Estate (S 205) 2014, driver assistance systems, PRE-SAFE PLUS (german version)
Mercedes-Benz C-Class Estate (S 205) 2014, driver assistance systems, radar, stereo camera and ultrasonic systems (german version)
Mercedes-Benz C-Class Estate (S 205) 2014, driver assistance systems, Crosswind Assist (german version)
Mercedes-Benz C-Class Estate (S 205) 2014, driver assistance systems, Mercedes-Benz Intelligent Drive - all- round protection (german version)