Find during construction work in Bad Honnef Time capsule reveals 107-year-old secret of the Grafenwerth Bridge

Bad Honnef · Restorers have discovered a time capsule during renovation work in Bad Honnef's Grafenwerth Bridge. On Monday, the soldered copper tube was opened for the first time. Inside: among other things, an issue of the Bonner General-Anzeiger from 1915.

Coins, newspapers and a document are retrieved by Helena Kaldenhoff, Gereon Lindlar and Jutta Schmidt from the 107-year-old tube dating back to the time when the foundation stone was laid.

Coins, newspapers and a document are retrieved by Helena Kaldenhoff, Gereon Lindlar and Jutta Schmidt from the 107-year-old tube dating back to the time when the foundation stone was laid.

Foto: Frank Homann

The Grafenwerth Bridge does not want to reveal its big secret that easily: only a few days ago, restorers of the 110-year-old Rhine crossing discovered a time capsule inside the bridge during renovation work, and nobody knows how long it has been slumbering inside. "A previously unknown and undocumented time capsule has been installed in the bridge, which dates back to 1911 and was last extensively renovated in 1973," reports Thomas Heinemann, spokesperson for the city of Bad Honnef. With a hot air dryer and a lot of patience, graduate restorer Gereon Lindlar tries to elicit the secret from the 50-centimetre-long, well-soldered copper tube.

Steam rises as the concentrated heating beam begins its work to melt the solder strip of the chance find. "We found the time capsule behind a plaque that was mounted underneath a bridge arch," reported Jutta Schmidt, head of the civil engineering office of the city of Bad Honnef. Fortunately, the bronze plaque hangs so high that it would only be accessible with a long ladder. "For us as a city, it is something special to discover such a time capsule. Often we don't even know where it was placed when the foundation stone was laid," says Schmidt.

What could be hidden in the capsule? "We don't know," Lindlar admits, while his hot air dryer continues to work on the copper tube at 600 degrees. When he discovers tiny water bubbles on the surface of the find, he is sure that there could also be water inside the capsule. "Well, it could be Rhine flood water," Schmidt concludes. When the Rhine river comes out of its bed, it is not uncommon for the water to come up to under the arches of the bridges. "This has probably been the case quite often in the past 111 years," Jutta Schmidt surmises.

Since 22 November last year, experts have been working on the Rhine bridge, built between 1911 and 1912, which is the only access route across the cut-off meander to Grafenwerth Island. The Berck-Sur-Mer Bridge further south was built in 1976 as a steel bridge. What makes the Grafenwerth Bridge architecturally special is that it is one of the very first reinforced concrete bridges in Germany to have been built in what even building experts call this slender construction method and was therefore included in the list of monuments as a special building in 1993. As if pointing a finger at the discussions of today, the reason why construction work began in 1911 between the Rhine island of Grafenwerth and the banks of the Rhine is valid. "The bridge Grafenwerth was built to open up the island of Grafenwerth for local recreation and tourism according to the design of the Bad Honnef architect Ottomar Stein," explains Fabiano Pinto, head of the urban development division of the city of Bad Honnef. "For all the discussions we have today about the use of Grafenwerth, I find it interesting that 111 years ago the use was already so intensive that the bridge had to be built," says Mayor Otto Neuhoff.

When after 20 minutes the weld seams still seem to resist the concentrated jet of hot air, Gereon Lindlar single-handedly reaches for his plan B: "I need a pair of pliers, please," says the qualified restorer. Less than a minute later, he opens the lid of the copper capsule and peers inside.

General-Anzeiger from 1915 as the first find from the copper tube

Since he can't make out much, Lindlar puts aside his work gloves and puts on white gloves so that the possible finds won't be damaged. The first object he carefully retrieves from the darkness of the copper pipe leaves no doubt about its age after only a brief inspection: it is an issue of the Bonn General-Anzeiger dated Friday, 1 October 1915. "That's interesting: that's about three years after the actual completion," says the restorer with a gleam in his eye. Also from that day, respectively one day later, are the copies of the Deutsche Reichszeitung and the Kölnische Zeitung, which also come to light with Landlar's gloved hand.

The gleam in Lindlar's eyes increases a little later, however, when something comes out that is wrapped in paper. "It sounds like metal," he says, and he is not mistaken: wrapped in the damp paper are a number of - in the meantime recognisably oxidised - money coins from that time, including a three-mark piece. "The only thing they didn't put in back then was the gold mark," reports the expert from Bonn's Büro für Restaurationsberatung.

Another find has already become stuck to the inside of the tube: a document wrapped in cardboard that states that Wilhelm II, then King of Prussia and Emperor of the German Empire, had approved the construction of the Grafenwerth Bridge. It also lists which architects and master builders were involved in its construction. "Great documents for the archive," Neuhoff thinks. Restorers will now restore the finds. Whether they will then be returned to the copper tube and behind the bronze plaque, however, is questionable. Because: "We can be glad that these metals have not yet been stolen. We want to keep it that way," says Jutta Schmidt.

(Original text: Mario Quadt; Translation: Mareike Graepel)
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