Erasmus Bridge: reliable calculation and transmission of the clearance height


Erasmus Bridge in Rotterdam  

Opened in 1996, the Erasmus Bridge is the landmark of Rotterdam

  • Due to the North Sea tides, some ships are unable to pass under the Erasmus Bridge in Rotterdam at certain times.
  • So as to avoid any damage to the ships and the bridge, there are six display panels which visualize the current maximum clearance height.
  • The display panels receive the corresponding analog values from an AXC 1050 small-scale controller via the Radioline wireless system.

Customer profile

Project Manager Richard Hecker  

Richard Hecker is responsible for the integration of measuring and display systems at ÆVO

The Erasmus Bridge connects Rotterdam city center to the Kop an Zuid district. The southern section of the 802 m long construction can be raised to allow tall ships to pass through.

The ship's crew is informed of the maximum clearance height, which is dependent on the actual water level, via six display panels.


Control center for the Erasmus Bridge  

In the control center the bascule bridge is controlled and shipping traffic is monitored

Based on the values visualized on the six display panels, the captains of passing ships can decide whether to pass under the closed bridge or wait for the bascule to open.

The previous solution was wired and prone to errors, as well as being time-consuming and expensive to maintain. After the system was damaged beyond repair by several lightning strikes in 2014, ÆVO B.V. was commissioned to carry out the modernization project. The existing on-site visualization elements were to remain. In addition, a connection to the new control center was required.

Serial communication to the six display panels posed a challenge during the course of the project. This was due to the lack of documentation for the previous concept as well as the control of the displays. It was therefore necessary at the start of the project to determine bit-by-bit how to address the displays. The specialists then deduced which components were best suited to the task.


Axiocontrol AXC 1050 small-scale controller  

In addition to the AXC 1050 small-scale controller, I/O modules are also installed in the control center's control cabinet

The current sea level is recorded by two pressure sensors, converted into an analog value, and relayed from there to the AXL F AI4 analog input terminal. As part of the Axioline station, the input terminal then transmits the data to the Axiocontrol AXC 1050 small-scale controller for evaluation. The maximum clearance height, which is shown on the display panels, is then calculated based on the difference between the sea level and absolute height of the Erasmus Bridge.

For serial data transmission to the visualization elements, the AXC 1050 controller has been supplemented by the AXL F RS UNI serial communication module, which transmits the calculated clearance height value as a serial signal to the six display panels via the Radioline wireless system.

For each visualization element attached to the Erasmus Bridge, ÆVO has set up a point-to-point connection to the respective directional antenna on the roof of the control room. Directional antennas were also installed on the six display panels to receive the serial signals, so that the calculated clearance height can be displayed. To prevent damage caused by surge voltages and thereby increase the failsafe performance of the solution, the coaxial signal interfaces are protected by attachment plugs with Lambda/4 technology.

The automation specialists from our Dutch subsidiary, Phoenix Contact BV, also implemented all the programming tasks in accordance with ÆVO's specifications. The AXC 1050 small-scale controller was programmed with a PLC programming language standardized in accordance with IEC 61131-3. The international standard harmonizes programming languages, command sets, and structures for automation systems. This means that the programs created can be easily ported to different platforms and used there. The team from Phoenix Contact's Dutch subsidiary also configured the Radioline wireless solution and connected it to the control system.


Various components and systems from Phoenix Contact's broad product portfolio were used in the solution to visualize the maximum clearance height below the Erasmus Bridge.

The optimum solution for the task in Rotterdam was developed jointly with the ÆVO team, thanks to the extensive expertise that our employees have gained over many years in infrastructure applications. Following the site acceptance test, the entire application was integrated into ÆVO's regular maintenance and 24/7 emergency service.


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