Rhomberg Sersa Bahntechnik

There is no way around ProVI
How Rhomberg Sersa is driving the digitalisation process forward thanks to ProVI

The Rhomberg Sersa Rail Group is a globally active Austrian-Swiss company with 2,800 employees that specialises in the construction and maintenance of railway infrastructure. The railway technology company’s customers include both private and public infrastructure operators in the DACH region, such as DB, ÖBB and SBB. However, clients from North America, Great Britain, Northern Ireland and Australia are also among its customers. Dominik Grahammer has been working as a planner and modeller for BIM at Rhomberg Sersa Bahntechnik GmbH, a subsidiary of the Rhomberg Sersa Rail Group, for 1.5 years. In the Digital Rail Services department, his focus is on digitising construction models, preparing them for the construction site and thus advancing the digitisation process. This also applies to the creation of the slab track and the mass-spring system for Stuttgart’s new main railway station.

The first step in the digitisation of construction models is the reality capture of the terrain. Either point cloud data or a so-called mesh is then sent to the modellers, who use ProVI to create an as-built model. These models are subject to very different requirements depending on the application. In the next step, digital engineering, a 4D process simulation was created from the model using the dProB planning software from Building Information Innovator GmbH. “Finally, the whole thing is brought back to the construction site,” explains Dominik Grahammer. “With 4D simulations, we can help site managers to optimise their processes. In addition, the model can be prepared for 5D, meaning that cost estimates for the construction site can be created using the model. This no longer has to be done manually in Excel lists – the costs are generated directly from the model.”

Stuttgart Central Station project

As part of the Stuttgart 21 project, Rhomberg Sersa was commissioned to construct the mass-spring system and the slab track in the area of the south and north ends of Stuttgart Central Station. A mass-spring system reduces the transmission of vibrations caused by railway vehicles and is therefore preferably used for railway tunnels in built-up areas. For this project, Dominik Grahammer modelled the slab track, rails and sleepers in ProVI. Although the mass-spring system was not modelled in detail, it was modelled schematically to make the concreting sections clear. His colleague then created a 4D simulation in dProB that shows the entire paving process, from material transport to determining the position of the surface.

This was particularly important because the space available was very limited. It was initially unclear whether there was enough space on the construction site for all the parts required for the installation. It had to be clarified whether all the materials could be delivered in one transport train or whether the installation would have to be carried out in several batches. “With the help of the 4D simulation, we were able to determine how long it would take to bring the material to the construction site and carry out the installation,” reports the planner and modeller. As a result, a video was created that shows which parts need to be placed where in order to be optimally installed. Important for the planning of the construction site were the edge paths and spandrels on which material was placed. For example, switch parts or sleepers first had to be placed on edge paths next to the track before they could be installed.

Challenges: high time pressure, good preparation, small file size

“We were under a lot of time pressure because our model was needed on the construction site as soon as possible. Since the Stuttgart 21 project is already known to have major delays, the aim was to build very time-efficiently,” continues Dominik Grahammer. “That’s why we decided to realise the project in ProVI. We had a shell model of the north-western part of the building from Revit and modelled the rest in ProVI.” The model was ultimately created in less than a month and the entire project was completed within three months.

In addition to the great time pressure, another challenge was to prepare the model for the 4D simulation accordingly, i.e. to already store the corresponding attribution, for example, which concreting section is where, the correct rail pitch or other information important for the 4D simulation. And the file size should also be kept as small as possible, because such a model can quickly become too large, as Dominik Grahammer describes: “My experience shows that the models should have a maximum file size of half a gigabyte so that you can still work well with them in the 4D simulation software. That’s why you have to weigh up exactly what you model and what you don’t. With ProVI, we were able to do this very easily.”

Reach your goal easily with ProVI

The planner appreciates the quick and easy handling of ProVI: “The software is very user-friendly. We worked a lot with rules. To model the edge paths, for example, we created user strips and were able to define them very quickly. That made things a lot easier for us. In addition, the routing and the calculation of the turnouts in ProVI work very well. In this case, 23 single turnouts and two double crossing turnouts were in place very quickly, within one day. The fact that all the guidelines are stored means you can route quickly and without much prior knowledge, and the modelling is greatly simplified.” What the planner also appreciates about the infrastructure planning software is that there are many options for exchanging data: “ProVI accepts almost all common data formats. It is very important for us that ifc files, i.e. Open BIM formats, are supported because we also work with other programmes and have a way of exchanging data here. At the moment, ProVI is at the forefront when it comes to infrastructure modelling. There’s no way around ProVI when it comes to creating infrastructure models, especially for us in railway construction.”

Extremely satisfied at support level

Dominik Grahammer also rates the collaboration with ProVI Support as very good: “I’m extremely satisfied at the support level. You get feedback very quickly and the staff are all extremely friendly.”