For this entry, we have an interview with Thomas Vogel of Zürich’s ETH, one of two institutes of the Swiss Federal Institute of Technology. He is a Full Professor at the Department of Civil, Environmental and Geomatic Engineering and Head of Prorektor Doktorat / Head of Institute of Structural Engineering. Between 1995-1999 Professor Vogel chaired the Zürich branch of the Swiss Society of Engineers and Architects (SIA) and since 2005 he is member of the Administrative Committee of the International Association for Bridge and Structural Engineering (IABSE).
Please tell us a bit about yourself. Where did you study and what is your professional background?
I studied Civil Engineering at ETH Zurich from 1975 to 1980 and graduated with a preliminary design of a cable stayed bridge, supervised by Prof. Pierre Dubas. Then I moved to Chur (Canton of Grisons, one hour from Zürich) to work with Hans Rigendinger, the successor of Christian Menn in the consulting office. In 1986 I moved back to Zurich to become one of two chief engineers in the company GUZZI AG, owned by Ugo Guzzi, an engineer from the Ticino, the Italian speaking part of Switzerland and designer of the Biaschina viaduct. The main reason was the opportunity to lead two major projects, namely the Preonzo-Claro viaduct, a 500 m long bridge in the Ticino, that became a pioneer project for external post-tensioning, and the extension of the main post office in Zurich. In 1992 I was appointed Professor of Structural Engineering at ETH Zurich.
Is there one aspect of structural engineering that you focus on? Do you have a favourite class that you teach? If so, which one is it and why?
My core topic in both, teaching and research is existing structures. I developed the respective course and have the opportunity to directly integrate new findings. What I like most, however, is not frontal teaching but supervising students in their own project works. Like this I can make best use of my practical experience of more than ten years in structural design and consultancy.
How has the teaching of structural engineering evolved over the last twenty years?
Students are more trained not only to calculate but also to communicate the results. Exact calculation has lost its importance because it can easily be done by respective computer programs. Validating of results, however, has become more important.
Do you have any recommendations for students in their learning styles today (such as more experimentation and site visits)?
Although almost everything can be found on the internet, it makes sense to read a book from time to time.
Are you witnessing any particular trends with regards to materials (either steel, concrete, or even plastics) in bridge building?
Concrete (the material I am most familiar with) has developed a lot in terms of strength, durability and reliability of the production process. The future is in the intelligent combination of all building materials.
Many of the world’s greatest bridges have been built in the last 140 years and have crossed the widest rivers, bays and valleys. It was a time characterized by untold amounts of innovation. Do you think that the 21st century will be equally innovative in bridge building? Will the innovations be more about the economy of materials? In what directions should we be looking?
In densely populated and well developed regions (like Switzerland or Western Europe), open roads are not accepted anymore as such, even though everybody wants to use them. That means that bridges are replaced by tunnel to cross below obstacles instead of above them. In developing regions like Asia or South America bridges still have a great future.
Bridge building was often seen as public sector projects geared towards economic development in tough times. One famous example is the Golden Gate Bridge during the Great Depression. Looking at the 2008 crisis, stimulus in infrastructure played a large role in developing local economies around Europe, but also particularly in the US. Did new bridges become part of the equation or was the economic stimulus more about upgrading them?
In developed countries the maintenance of existing infrastructure has become equally important as extending it. Since public expenses to overcome an economic crisis tend to come too late, maintaining and upgrading existing infrastructure is preferred, because the public approval processes for infrastructure upgrades are much shorter.
Looking at the Swiss Legacy in bridge building (engineers such as Othmar Ammann, Robert Maillart and Christian Menn, in whose offices you worked) do you think that Switzerland’s geography strongly influenced the country’s leadership in bridge building in the late 19th and early 20th century?
Yes. (Moderator:I thought that the answer was yes, but I wanted a Swiss structural engineer to answer the question, so that there would be no doubt.)
Is there one strait, valley, river or canyon that still deserves a bridge? If so, which one would it be? Is it just a great idea or is there an economic case for building such a bridge?
Economy is an important issue. Mankind should not build bridges for the pure sake of technology because the conservation of landscape has become equally important. In the case of Gibraltar, a tunnel may be justified and preferred by technical reasons. The design of a Messina bridge has been completed, but economy is more than doubtful. Bering would rather be a political project joining the United States and Russia, beyond any economic justification.