Safe, weight-optimised construction

A number of decisive advances have also taken place out of sight beneath the attractive exterior of the new Citaro. Although the bodyshell continues to be based on the proven technique of annular frame members – one of the innovations from the first-generation Citaro – it has been made even more rigid to afford passengers yet greater protection in a side-on collision.

Intelligent engineering lowers weight while increasing strength

A series of individual measures have been implemented to give the bodyshell superior strength despite its lower weight. One example is the newly designed pressed sheet-metal parts on the new Citaro, which combine the horizontal and vertical bodyshell elements around the window posts into a single multi-dimensional section resembling the hilt of a sword. Because they are built from a single pressed part, they are both lighter and stronger. Shifting the laser welding further out from the joints has produced a very sturdy connection. The developers have achieved similar results with the new castings for the door portals: although they have been reinforced, their walls are thinner, making them lighter than the previous design.

The expansive glazing on the new Citaro is lighter in many parts too: partially reducing the glass thickness from 4.0 to 3.15 mm compensates for the larger windows’ greater initial weight.

Green components above the doors: Cast corners in thin-wall cast steel. Help to reduce weight and optimise strength. - Green components between the axles: Laser-welded stampings. Help to reduce weight and optimise strength. - Red components in the front section: Reinforcement measures in accordance with ECE R 29 (pendulum impact)

The roof frame is also new: it is based on two longitudinal hoops running almost the entire length, and now weighs just 110 kg on the 12 m rigid bus compared to the previous 137 kg – without sacrificing stability in any way. This new construction furthermore allows flexible positioning of any superstructures on the roof, while also reducing the number of different variants from over 50 to just 15.

New crash element to protect the driver in a collision

An outstanding safety feature that has been integrated into the extended front end of the new Citaro is a crash element to provide additional collision protection. This, together with the strengthened A-zero pillars and a frame design that has been engineered to channel impact forces directly into the substructure, means that the new Citaro already fulfils the requirements of the future pendulum impact test for coaches as laid down in the European ECE R29 standard.

Red components in the front section: Reinforcement measures in accordance with ECE R 29 (pendulum impact).

The Citaro already complies with future ECE standards today

The bodyshell of the new Citaro was developed with the future ECE R 66/01 standard in mind too. This specifies a much larger survival space for the interior in the event of the vehicle tipping over than was previously the case. Although the new regulations only come into force in 2017, the new Citaro already complies with them today.