The secret of the “concrete” doors in the Mercedes-Benz Museum
There are “concrete doors” all over the Mercedes-Benz Museum. They are at heights impossible to reach with your hands above your head. They come in all types of sizes. But what is their secret?
They are the result of this sophisticated strategy that most would find impossible to pronounce. Trompe-l’oeil. Deceive the eye. That is what you would call this in English. You get to see them the moment you step inside the 35-meter tall atrium of the Mercedes-Benz Museum in Stuttgart, Germany, where futuristic lifts go up and down the walls. Those walls where, if you pay attention, you get to see five large squares. Those are the concrete doors. But what are they for?
Embedded in the walls, camouflaged in the same color, they measure 4 meters high and 3.50 meters wide. It is enough to allow the entry or exit of any truck, bus, van, passenger or race car in the collection. To lift them up, or bring them down, experts use a crane system with a platform.
The “concrete doors” of the Mercedes-Benz Museum – How did they end up looking like this?
Each door would weigh around six tons if made of concrete and would require gigantic solid hinges. But – because there is a “but” – they are not. That is the actual trick. The doors are not made of concrete, but of something much lighter. Instead, they feature a hollow steel construction covered with a gypsum fireboard. Therefore, despite its impressive size, each “concrete door” actually weighs less than a ton.
During the construction of the Mercedes-Benz Museum, in 2005 and 2006, construction engineers, under the supervision of restoration specialist Jurgen Kuntel, created the deceptively real-looking representation of concrete. The procedure was time-consuming and involved craftsmanship and patience. The last step is sanding with fine and finest grits. “The surface must be identical to the surroundings in terms of abrasion so that the applied color is as textured as the real concrete,” Kuntel explained, “otherwise shadow effects occur that undo all previous perfection.”
That is why he repeatedly checked the surface with his hand and was only satisfied when the smoothness on the door matched that of the concrete walls.
