Fabricating bridge sections close to where they need to be installed and lifting them in as few pieces as possible significantly limits project costs and disruption to local communities.
Mammoet’s specialist equipment and heavy lift engineering expertise helps to unlock these Accelerated Bridge Construction (ABC) methods, enabling bridges to be installed in just a few days, or even hours.
The bridges are located near Budapest Park, a busy area for tourism, and sit above a street called Soroksári út that serves as a main artery into Budapest. Closing this road for months or even weeks wasn’t an option.
V-HID had seen Mammoet perform successful bridge launches in the past using Self-Propelled Modular Transporters (SPMTs) and requested its help to utilize them for this project.
The SPMTs proved to be the perfect tools for the job – allowing the bridge to be installed in one piece and reducing the project schedule from weeks to days, while also preventing the need for costly civil work on the street below.
Self-Propelled Bridge Installations
V-HID contacted Mammoet for its assistance with the Ferencváros – Kelenföld railway line capacity expansion project in March 2025.
There were two bridge structures (North and South), each weighing 2,200t and measuring 108 meters in length and 20 meters in width. The south bridge was to be installed first with the north to follow approximately a year later.
V-HID has launched bridges in the past using skidding systems. This process would have involved pre-constructing support towers in the road and then skidding the bridge over these temporary foundations.
This would have resulted in having to drill 20-meter piles into the road, which would have meant closing it off to bring in massive drilling machines to the site.
To avoid this, Mammoet suggested assembling support masts on top of SPMTs and then driving them underneath the bridge. This method would be quicker and avoid costly repair work to the surface of the road, as the masts could be removed as easily as they were brought to site.
The bridge sections were fabricated and delivered on trucks. There, they were assembled, coated and welded, ready for installation.
The biggest challenge was space, as three separate areas were required to receive, store and assemble the bridge sections, the SPMTs and the support masts.
With space so limited, an old tram station was removed to create an area to assemble the support masts.
Four sets of SPMTs were used for the operation; working at two levels – upper and ground – to launch and support the weight of the bridge.
The bridge was driven forward until it was cantilevered. The first set of SPMTs then drove underneath it with its support masts.
Drawing upon its global fleet of equipment, these supports comprised sections of an MSG crane mast with a base frame on top of them. There were four masts per SPMT set, with load spreaders underneath them.
The project saw SPMT sets used twice in rotation; once at height to launch the bridge from the abutment, and again at ground level to drive it across the gap. As the bridge was driven further forward, more SPMT sets were gradually lowered in single lines from the upper to the ground level using a 400t mobile crane.
Once these SPMTs had been reconfigured, they collected four support masts from the assembly area and then drove them underneath the bridge.
This process continued until three sets of SPMT (4 x 12 axle lines) were under the bridge, allowing it to reach both abutments. A total of 176 axle lines were used for the operation.
Reopening before rush hour
In this instance, the SPMTs were the perfect alternative method to using a skidding system. The obstruction of this main artery was reduced to a single weekend, starting Friday morning and then reopening before rush hour on Monday morning.
The north bridge launch will follow the same steps as the first but will be more challenging, as there is now even less space due to the south bridge installation.
“Our expertise and flexibility in terms of engineering solutions and equipment, allows us to adapt to technical challenges,” says Jordy van der Hoeven, Project Manager at Mammoet.
“We always find a way because if we don’t have something in our fleet to fix or solve a problem, we build it”.
