The San Michele bridge is regarded as a symbol of industrial archaeology and one of the most interesting achievements of Italian engineering in the 19th century. 

Built in 1889, the 266m (872ft) long iron bridge, which is also known as Paderno’s bridge, was constructed from 2,500 tonnes of riveted beams held together by 100,000 nails! 

In the early 90s, the bridge was deemed structurally obsolete, and inadequate to carry the amount of road and railway traffic across the Adda river about 50km (31mi) from Milan, Italy.

There were talks to restore the bridge with a budget of 42 billion Italian lire at that time but the proposal fell through. However, a new redevelopment plan was announced by the end of 2015. 

A total of 25 million euros was allocated to restore the overall structure and upgrade it to support higher-speed rail transit – by increasing the speed from 15km (9mi) per hour to 75km (47mi) per hour, and improve the safety of pedestrian crossings. 

The bridge repair was awarded to Impresa Luigi Notari, an established construction company in Milan. The blast cleaning and painting process which began from July 2019 to quarter two of this year was completed using GMA’s PremiumBlast™ garnet.