The major motorway bridge collapse in Genoa, killing 43 people and injuring many others on the 14th of August, prompted some thoughts about human factors and construction failures.
Over the centuries, bridges, cathedrals and buildings of every sort have fallen down, sadly in most cases with significant loss of life. However, many ancient buildings, such as some of the Roman aqueducts, remain standing. Other buildings, where ambition exceeded the technology of the day, fell down. A prime example is Beauvais Cathedral in Northern France, started in the 12th century, which has and continues to suffer from structural failures to this day.
A few minutes’ research on the internet will give a long list of bridge failures and the apparent reasons for these collapses; everything from earthquakes to design failures, and including poor maintenance, weather extremes, and collisions with trains, vehicles and ships. Perhaps the most curious was the loss of two bridges linking Halifax and Dartmouth, Nova Scotia, allegedly due to a curse by a Mi’kmaq chief in 1753. Eventually, to ward off superstition, another chief was invited to lift the curse in 1955.
Dealing with superstition is obviously not enough to ensure that bridges don’t fall down though. Right across Europe and the USA, literally hundreds of bridges are at risk due to lack of maintenance and monitoring. Governments of every country face budgetary restrictions, but because bridges seem permanent, they perhaps don’t get the detailed care and attention that they require.
And yet, it is amazing that bridges built by the great Scottish engineer, Thomas Telford 1757 - 1834, remain standing today, carrying heavy trucks and buses when the heaviest road transport of his day was a horse and cart. Of course, maintenance and some strengthening will have been required, but it was his vision and approach to design and risk assessment that ensured the success and longevity of his structures.
If we take time to study the many apparent causes of structural failures, there will never be just one single factor. At the heart of each one, there will have been some change that has triggered the series of events that led to the collapse. This is not just another example of human error and the last person to ‘touch the controls’ being at fault, but about the thought and planning behind every design and the need for rigorous ‘Front End Engineering’, as well as constant monitoring through changing conditions. Remember that the Romans and cathedral builders didn’t have the powerful computer programs that we have today.
So, whatever the problem, it must be about human factors, whether by design or maintenance, and never just bad fortune.