Restoration of platform roofs Groningen in Obdam
26 March 2022
Regular visitors to Groningen station have been missing them for a while: the more than 120-year-old monumental platform roofs. They were temporarily removed and are currently being thoroughly restored more than 160 kilometers away, in two sheds in Obdam. We spoke with project leader Stephan Meijer of Anton Rail & Infra, which is carrying out the restoration, about this large-scale project.
Anton Rail & Infra dismantled the high platform roofs near the station building in 2020 on behalf of ProRail. Before that, a lot had to be prepared. “From determining the way in which we would carry out the project to the logistics plan for getting things to and from Groningen. Things that I am involved in as a project leader”, says Stephan. “In addition, I also work as an implementer. Because what I came up with with the team inside, I want to experience outside as well.”
The platform roofs, which were dismantled in several train-free periods, went from Groningen to Leeuwarden, where the old layers of paint were removed. Then they were transported to Obdam. That is where the large-scale research work began. “We had to inventory, measure and calculate the condition of more than 300 steel elements. What can still be used, what needs to be replaced, what can be repaired? We wanted to preserve as many historical materials as possible, but at the same time the roofs must also be suitable for displaying in Groningen again for the next hundred years.”
The roof constructions were in worse shape than had been anticipated. Partly due to the layer of paint that was on it, it seemed to be not too bad with the naked eye. But when it was removed and the thickness was measured with an ultrasonic meter, it turned out that in some places the steel was no longer as thick as expected, and the number of recovery points doubled. Consultation with involved parties followed; how do we restore the steel construction in such a way that it is strong enough and yet still looks monumental?
Stephan: “The relationship with client ProRail, engineering firm Movares and the Groningen monument committee is good. And that is also necessary in a project like this. In consultation we came up with a design with shims that will be recessed. We made three test frames and then there was a go. In January we started repairing the construction. We are welding with about 10 employees. This takes place in two large halls because we need space to put parts together to see if it all fits. We do not want to be surprised when we replace the hoods in Groningen.”
In addition to repairing the steel structures, much more is happening in Obdam. Part of the cast iron columns on which the caps rest must be renewed. “We make them one-on-one with a mold into which we pour cast iron. We provide them with a year, so that it will soon be clear what the old and what the new columns are. We also make completely new parts of the hood. Such as the canopies at the end of the platform roofs. These once disappeared in connection with the arrival of higher trains. We are going to copy and replace them on the basis of drawings from the archive.”
Once the parts have been repaired or renewed, they are preserved in a different location. Then they are protected against external influences and they get the right color. Then they are ready to go back to Groningen. But before they can be put back there are a few things that need to be done. For example, the Belgian bluestone consoles at the station building on which the platform roof rests, as well as part of the masonry, must be restored. There will also be new gutters. This work is being carried out in close coordination with contractor Strukton, who is busy building the underground pedestrian passage, bicycle tunnel and bicycle shed.
‘I am looking forward to rebuilding it’, Stephan Meijer, project leader at Anton Rail & Infra
“It is an extensive and time-consuming job with many different facets. The special and challenging thing is of course that we want to preserve the monumental value. I look forward to rebuilding it and then being able to show what we’ve been working on all those years far from Groningen. We are rebuilding something unique, and I can say that I contributed to this.”
View the photos of the dismantling of the platform roofs here.