Can you believe they are proposing that the Forth Rail Bridge may have to be demolished? One of the points raised is about debris falling off the bridge, and yes this is true. However, every structure that is built has a safety factor. A factor of 1 means it can support the maximum predicted load i.e. the worst case scenario. Most structures are built with a safety rating of between 1.5 and 2, for understandable reasons. the Forth Rail bridge was built shortly after the Tay Rail bridge disaster where the bridge collapsed whilst the train was crossing. Thus the safety factor of the Forth bridge is 5. Thus the occasional loss of a rivet is not exactly crucial to its design, it has ample redundancy.
Unlike for example the Millenium Bridge which swayed in the wind. However, it was designed to do this and be safe, but the 'public perception of risk' stated that it was unsafe and they had to ship in a special stabilising system. Unfortunately only 2 exist in the world and the closest was in South America. And it can't be flown in. So the bridge had to be shut ofr 6 months. Another great "Millenium" project. Which reminds me, what's happeing to the Millenium Dome these days? Has it been demolished?