There is one thing that we expect from monuments and that is that they withstand the passage of time, standing strong and proud.

But what if they don’t? Our company’s restoration of the Brandenburg Gate in Berlin is a good case in point.

At the beginning of the 2000s, this symbol of German history underwent a general renovation, and about time. For decades, this structure right on the border of divided Berlin had been untouched by the city’s infrastructure services. However, after the fall of the Berlin Wall, the Brandenburg Gate was suddenly a central part of the ever-pulsating metropolis while exhaust fumes and environmental toxins gnawed away at the masonry.

The deterioration became more and more apparent during the restoration work – especially when it was discovered that inferior material had been used for some of earlier restoration work on the columns. The condition of one column was so poor that it was in real danger of collapsing.

Therefore, in 2002, the restorers decided to carry out a spectacular replacement operation. The affected column underwent ‘open-heart surgery’ by being put into a kind of suspended state and replaced.

This was a demanding feat of engineering, partly made possible by HBM force and displacement sensors. With these sensors (and the associated measuring amplifier), the mechanical load condition could be determined at any time, bringing certainty and confidence to every step of the investigation.

At that time, continuous structural monitoring with sensor technology opened a new chapter in technology. And even today, this method is still widely used and based on a wide variety of sensor technologies (for example, strain gauges or Fiber Bragg Grating sensors), depending on the challenge at hand.

So, when we look at the Brandenburg Gate, we can be proud knowing that measurement technology from HBK has contributed to ensure this 18th-century, neoclassical monument’s strength and stability.