The reflection of the historic village shimmers in the water. The terraces, the ancient buildings, the church of St. Urbanus… A stream called De Bullewijk runs through the heart of the municipality of Ouder-Amstel. Just before it flows into the Amstel River it goes past a historic treasure: the Kerkbrug bridge. For centuries this listed structure has connected the village of Ouderkerk aan de Amstel to the Ronde Hoep polder. Now it is also connected to the Internet of Things.
Two black boxes the size of a matchbox connect Kerkbrug bridge to VolkerWessels. These smart sensors installed by Asset Insight enable the VolkerWessels subsidiary to monitor the bridge in detail. How severe are the traffic vibrations? What is the average angle when the bridge is open? How often and when is the bridge open? “For example, you can see that the bridge opens much more frequently and for longer periods on sunny days in the weekend,” explains Noël Steentjes, pmanager Monitoring & IoT at Asset. Insight. This knowledge yields huge gains in terms of maintenance Noël: “After every 100 openings the customer need to drop by to lubricate the bridge and to check the rubber fenders and the paint. We now know that the bridge opens nearly 500 times in the course of a warm summer month compared to fewer than 100 times between September and January.”
Roaming through the data
The raw data has stories to tell. “It’s obvious to us when it’s raining: there is much less water traffic and the bridge is never open for longer than two minutes. But on sunny days that can be as much as seven minutes, which means stationary traffic, exhaust fumes and congestion. Obviously this is valuable information for municipal and provincial authorities.”
It took Noël three visits to the bridge to install and fine-tune the sensors, a process involving a lot of testing, trialling and adjusting. Noël: “The sensor works by angular displacement, just like your smartphone. Our first test showed that the traffic vibrations were preventing the sensor from accurately registering the closing of the bridge. Given that we wanted to measure these vibrations as well, we had to adjust the sensitivity with great precision. Which goes to show that installing sensors tends to be a precision task that requires a great deal of focus. But it is always a great moment once everything is installed perfectly and you start to see the data coming in.”
The courage to innovate
What I like about my work? Learning something every day. My job takes me to many different places and each new job requires me to acquire new knowledge. Measurements on a bridge for example are completely different from those on for instance a sheet pile wall or railway. This makes the start of each new job exhilarating: you know you have a lot to learn and figure out in order to make it a success. But however much you know, it’s always a case of trying things out and experimenting. That is the essence of innovation: having the courage to fail but to keep on trying.