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Q&A with GEOGRID AG: How to Automate Track Monitoring for Rail Infrastructure Projects

Founded in 1960, Thun-based GEOGRID AG (formerly Dütschler + Partner) has long specialized in rail monitoring in Switzerland. Its customers include municipalities, industrial companies, construction companies, engineers, architects, builders, property owners and notaries.

In winter 2022, the company invested in the Trimble® 4D Control™ (T4D) deformation monitoring software’s T4D Rail software module. We asked Moris Berchtold, project manager of engineering & surveying and head of the department of monitoring for GEOGRID AG about his T4D experience.

Q: What are some of the monitoring challenges you regularly face?

A: In Switzerland, Swiss Federal Railways has very strict requirements about what rail parameters must be monitored—twist, versines, and displacements, and to what accuracy. The calculation of those parameters from the data gathered on-site has been largely manual in the past.

For instance, we would manually calculate the prism offsets from the rail and put all that data in a spreadsheet. When the area to be monitored is greater than say 200-300 meters, that takes a lot of time. I would often spend up to a full day defining a long rail segment. The risk of error is high. 

That entire workflow is streamlined and automated with T4D Rail. I import a track file from the Trimble Access™ Track Gauge Survey app to T4D Rail and the track is automatically created. The whole track is defined in a few minutes, and we can start monitoring. 

Q: How challenging was the implementation of T4D Rail and the Trimble Access Track Gauge Survey app? 

A: We were already using T4D so the transition to T4D Rail was very straightforward. We have what we call a rail garden on the grounds of our Thun office building that includes a self-made rail track structure, a total station and prisms. That’s where we test all of our equipment, both hardware and software. We set up a test monitoring project in the rail garden and verified the workflow and the accuracy of data collected and reported using the new technology. We knew within one hour of testing that it worked as needed and how to use the solutions on a project. For the Trimble Access Track Gauge Survey app, I especially like that it automatically turns to another prism with a simple click, which saves time during fieldwork.


A self-made rail structure, a Trimble total station and prisms monitoring setup to test T4D Rail workflows. 

Q: Would you describe a recent rail monitoring project and the T4D workflow?

A: Earlier this year, a customer asked us to support a rush project. The contractor was building a retaining wall between the river and the railroad. We got a call on a Wednesday afternoon and needed to install the monitoring solution the next day along a 340-meter stretch of rail. That monitoring solution needed to operate 24 hours a day throughout construction, about six months.

We installed four total stations and 180 monitoring prisms. We measured the rail position with the Trimble Access Track Gauge Survey app and uploaded it to T4D Rail, which allowed us to monitor horizontal and vertical displacements, as well as twist and the versines, which are measurements required by the authority.


A visual of a mounted Trimble S9 total station. 

There are cases when prisms in the field get destroyed or cannot be used anymore, so they have to be physically replaced. With T4D Rail, I can update the rail section very quickly. Before I would have to manually update all the calculations. Now, I can update in two or three clicks. I had to do it twice on this project and it worked great.

T4D Rail also saves a lot of time when it comes to evaluating measurements. From one table, I can see the parameters in a format very similar to the Swiss Federal Railways' requirements. Rail-tailored graphs, and the possibility to give access to those outside of our monitoring team to follow the monitoring program, are what make it easy to share information and keep everybody in the loop.


A closeup visual of a prism mounted on the side of the track.

Q: Do your customers realize any benefit from the improved workflow?

A: Absolutely. I especially like the way data and access can be shared through the T4D web interface with customers. It makes no difference if it’s real-time automated or semi-automated monitoring, customers will always have access to the data and of course, be informed as soon as something changes. This includes automated alarms that trigger an email or other notification when movement exceeds movement thresholds determined by the customer. With a spreadsheet, we were the only ones who really understood what was happening; it wasn’t very visual. Now with T4D Rail, we can easily share that knowledge in a clear and easily digestible format. 

As I mentioned, deliverables from T4D Rail can be used to create specific rail reports that align perfectly with the requirements and specifications of Swiss Federal Railways. That's a really good thing. I can export that file easily and give it to the customers however often they require. For the rail monitoring project I talked about above, the customer noticed right away and said the reports were easy to understand. 

Q: How did you use the Trimble Access Track Gauge Survey app?

A: Previously, we used rail shoes to measure the track. Now with the app, it’s easier to measure the actual rail position; much faster than the rail shoe. It allows us to measure the track and then export the data we need to T4D Rail. We don't have to manually calculate anything anymore. The track file from the Trimble Access Track Gauge Survey application has everything we need.


The Trimble Access Track Gauge Survey app on a Trimble TSC7 controller for field data capture. 

If you would like to talk to someone from Trimble about the benefits of using the Trimble 4D Control Rail module, contact us here.