Most vehicles on our roads are equipped with conventional doors that are either hinged at the front-facing edge of the door or (in some occasions) on the rear-facing edge, thus allowing the door to swing outward from the body of the car. Among sliding doors there are also some more exotic alternatives such as gull-wing doors or scissor doors mostly used in luxury vehicles like the Mercedes-Benz SLS AMG or the Lamborghini Aventador. These doors rotate upward to open, which may be difficult should the car roll over and come to rest on its roof, and exiting the vehicle by opening the doors would be almost impossible. Learn more about the vehicle manufacturers' solutions for this type of accident in this technology update!
Gull-wing doors are doors that are attached to the roof of the vehicle and open up. A portion of the roof opens together with the door to allow for easy entry. Scissor doors are hinged on the A-post and also open in upward motion. On both versions the opening process is normally supported by pressurized cylinders, so that the door does not close under its own weight.
Should the vehicle be involved in a collision and come to rest lying on its roof, opening the gull-wing or scissor doors will not be possible in most cases. That is why the vehicle manufacturer's engineers came up with a very special solution on the late model vehicles Mercedes-Benz SLS AMG and Lamborghini Aventador.
Should those vehicles come to rest on the roof, the control unit for the supplemental restraint system detects the vehicles position and activates pyrotechnic charges on the door hinges. In cases of the Mercedes-Benz SLS AMG every of the four door hinges is equipped with such a pyrotechnic charge which disconnects the hinge arm from the door. The pyrotechnic charge does not directly sever the hinge arm but activates a mechanism that mechanically disconnects the door and the hinge arm.
For emergency responders this means that after opening the lock the door may be horizontally pulled off the hinge arms from under the vehicle. This is why it is essential to try the door lock first. If this doesn't work, the door locks can also be opened with hydraulic rescue tools. In case of the Mercedes-Benz SLS AMG the lock is located on the front side of the door where the A-post and the rocker panel connect. To completely remove the door it is necessary to untie or cut the rod of the door support cylinders.