Vibrations, structural changes and temperature fluctuations are now being measured in the old Lundsbroa in Kristiansand. The University of Agder (UiA) has purchased iBridge smart data loggers from Smart Sensor Systems, which are now installed in several places inside the bridge. The project is a collaborative project with Agder County Municipality.

Four students at UiA construction design have followed the preparations and installation of meters at Lundsbroa. The students Christian Kristiansen Raabu, Morten Lindekleiv, Ole Gunnar Lund Jensen and Malin Wårøy Møll have used this as part of their bachelor's project at their studies in Grimstad.

The students created the "test bridge"

- We have been following the preparations together with Smart Sensor Systems for several months now. We were completely green on everything with sensor measurements, so this has been a lot of fun to be part of, says student Christian Kristiansen Raabu. We meet him on the underside of the bridge, where there is a small hatch to crawl inside the bridge. It's cramped and dirty inside, and you need a headlamp.

- In the preparations, we have learned how to use sensors to check for faults in constructions without having to be on site continuously to take samples. Now you can sit at home and follow the measurements on a PC screen, says Raabu.

- In anticipation of assembly on the bridge, we have made our own small "bridge model" and installed iBridge smart data loggers to test. It has been interesting to see how sensors pick up changes, when we have exposed the "test bridge" to external influences. Here you can follow vibrations and changes in the bridge pattern, says the student.

Project under the auspices of Agder County Municipality 

It is Agder county council that has started the project with measurements on the old Lundsbroa. We have made a county road available and are contributing funding so UiA will be able to develop a system to retrieve relevant information, says project manager in the county municipality, Vidar Ose.

The hope with this learning project is that we can gain more knowledge and experience with sensor technology on bridges, says project manager Rein Terje Thorstensen at UiA.

iBridge smart data logger well suited for bridge measurements

- This is a project in the middle of nowhere for our iBridge smart data logger. This is where it can really come in handy, says manager of project development Joakim Hellum at Smart Sensor Systems, who finds it exciting to follow the bridge measurements going forward.

Thygeson's memory

The old Lundsbroa is officially called "Thygeson's memory", or originally "Thygeson's memory", after the local magistrate Nicolai Emanuel de Thygeson who built the first bridge on this site in 1810. It was 504 feet long, 19 feet wide and had 12 bridge vessels. Today's bridge was built in 1938, and was a major extension of the bridge and an upgrade from wood to masonry.

Smart Sensor Systems offers simple and smart measurement technology sensor solutions for buildings, roads, bridges, railways, industry, renewable energy, water and sewage. We have offices in Oslo and Kristiansand.

For questions contact:
General manager Halvor Heiberg at Smart Sensor Systems, tel: 90 11 29 35

The top picture shows installation under the old Lundsbroa. From the left, project developer Magne Hellum and project manager Joakim Hellum in Smart Sensor Systems, and student Ole Gunnar Lund Jensen. Photo: Ragna Marie Henden

Lundsbroa installation iBridge

The old Lundsbroa in Kristiansand crosses the Otra

Lundsbroa installation iBridge

Student Christian Kristiansen Raabu on his way under the bridge

Installation iBridge 1

Mounted strain gauge for measuring changes in the bridge structure

Installation of iBridge in the bridge 2

Mounted iBridge, here with power supply. Can also be supplied with battery operation.