The Charles bridge in Prague is considered one of the most famous structures in the Czech Republic and it is currently being renovated. This article describes some of the problems you face when you try to restore a historic bridge.
Everything you look at has been poorly handled, including the balustrade, because it was not overseen. That is why we need the project to be stopped. If it isn’t, we’ll all be very unpleasantly surprised in a year’s time.
The engineer in charge from Mott MacDonald, Jiří Petrák, counters with,
I appreciate to be able to help Charles Bridge and for me to participate is the highest reward in my bridge engineering career. I feel we have been criticised for some steps along the way that are still on-going. The bridge is not finished. When we hand it over to the client and to the public, I think these kinds of comments will disappear.
Historic bridge renovations are difficult and like most old structures it is often easier to remove material until you hit a solid foundation. But if you do that, you can also alter the nature of the bridge and lose what made it special.
Which leads to another question, how much of an old bridge can you replace before it is considered a new structure?