“My best project? There are so many! Every project was so different and the challenges so diverse that it is difficul to name just one. The assembly design and the calculation of the Erasmus Bridge. Also, the design of the railway bridge over the Hollands Diep. It took seventy people, the entire south side of the second floor of the building, to achieve the design and thus the implementation on time. The bridge was fie years old and the guarantee period was over, and not a single train had travelled over it! Firstly, they had forgotten to order the train and in the absence of supervision during construction, it turned out that the train was no good anyway. This is what happens if the client does not utilise substantive professional knowledge. We certainly have this knowledge at Iv and I’m convinced that this is our strongest point.” Han Vos worked at Iv-Infra from 1986 to 2013 and is enjoying his retirement already for several years.

“If I have to mention just one project, then it has to be the design of the new lock gates for the Panama Canal. That was the biggest, most impressive and also my last major project. For Iv, this was then the largest project ever in man-hours, and yet it could have been much more. If we had tackled our ofer for the concrete construction work in a different way, then the contracted hours may even have been doubled. Obtaining that contract was a special story anyway. It started with two lawyers, one from Heerema and one from New Orleans. The project for the new storm surge barrier in New Orleans was discussed, just after Hurricane Katrina. They wanted to get it sorted out, but how? One of the two knew Rob van de Waal and approached him to assist with a design which would be ofered for the New Orleans storm surge barrier. The contractor (only just) wasn’t awarded the contract which also put an end to our involvement. But we had cultivated contacts there with Tetra Tech, the company that later cooperated with MWH Global to expand the capacity of the Panama Canal. I received an e-mail from Chicago asking, ‘Do you have knowledge of locks?’ Yes of course! Together with Rob, I went to Chicago to discuss the new lock complexes. It was then that we discussed lock gates on trolleys. In IJmuiden, similar old gates with rigid trolleys and rails were replaced by more flexibl ones, to avoid wheels and rails becoming worn. We then made a design for Panama with a rubber block on each trolley to absorb the movements and transfer the forces between the gate and the trolley. We submitted the design to the contractor, who was awarded the contract due to its attractive price. We were commissioned for the engineering of the gates and the operating mechanisms.” 

Han and his wife lived in Panama for two years for this project. “Living ‘far away’, where everything is different, was fascinating. What was so different?” Han thinks for a moment... “It’s a combination of a lot of small things. It is very hot there and nature is very different. For example, in March, around the rainy season, the entire forest is buzzing and suddenly, bears (‘gato solo’) are strolling through the garden, with their distinctive tails poking up above the grass. There is also corruption, you must always have money in your passport or wallet, especially at the end of the month. The police checks are always around the 13th or the end of the month. Their budgets are mostly used up by then and they start making extra checks for ‘violations’.”

Working internationally was also a nice challenge, says Han: “We had European experience at Iv, but not outside of Europe. We had to adjust our way of working. For example, in the Netherlands, we work on A4 paper, but internationally Letter format is by far the most used. This sounds like a small detail, but it meant that all our reports were not normally printable and were not easily read. So, I had our repro service produce special letter paper for us. We also learned how to use video conferencing or conference calls. What was the greatest challenge? The collaboration. Forming a team while we were in four different locations around the world. Try getting that to work as just one team.”

Something completely different, but something that Han has fond memories of, is coming up with the annual Iv promotion for the Steel Construction Day. “Yes, the tennis ball machine! We handed out butterflynets at the stand for visitors to catch balls with. If they caught a red ball, they won 25 Dutch guilders. If they caught a yellow ball, they were given a beer. There were all these people in suits jumping around with nets trying to catch balls. Also, the time that we made a bridge out of ice and visitors had to guess how long it would remain standing before melting. It remained standing the whole day, but when the trade show came to an end it magnificently collapsed when a suppot was removed. Another time was when visitors had to generate electricity with bicycles to race trains. When the huge bang from the starting pistol sounded, they had to cycle as fast as they could. The construction that walso a big hit. It was all a lot of fun.”