Four steel railway bridges, and one concrete bridge, will be replaced on the east side of the key rail hub – with minimal disruption to commuters.
Mammoet is carrying out these renovations with Dutch engineering company Dura Vermeer.
The bridge upgrades form part of the wider High-Frequency Rail Transport (PHS) Programme, which includes track optimisations, infrastructure adjustments and construction work inside the station building.
Mammoet will support the load-out, transportation, and installation of the three sections that make up each bridge. The components measure 24 and 28 meters in length and weigh 173 and 275 tonnes.
To keep disruption down to a minimum, the operation is happening almost entirely on water, with one bridge replaced every year from now until 2028.
The bridge sections are being fabricated by Hollandia, in the Netherlands. They will be shipped to the Oostertoegang aspect of the station on flattop barges travelling through the river De Lek and the Lekkanaal.
To enable passage underneath a low footbridge near the Oostertoegang, the main installation barge will be partly submerged in the water using copper pontoons weighted with water.
A 90t mobile crane, positioned on a temporary bridge, will remove the pontoons from the barge and replace them with Mammoet Self-Propelled Modular Transporters (SPMTs).
Mammoet’s Mega Jack 300 system will lift the bridge sections to a height of four meters on the deck, allowing enough space for the SPMTs to drive a support frame underneath.
The SPMTs will then rotate the bridge sections 90 degrees, so that they are in the correct orientation. They will then drive them off the barge, across steel mats, and onto support towers.
For each bridge, Mammoet will install the east side section first, then the west and finally the middle section – which will be lifted and installed over water, from the deck of the barge.
Leo de Vette, project manager at Mammoet, said: “As a reliable partner, we have been involved in this project since 2021. We came up with the approach to install the bridges on water to limit transport movements and disruption in the city centre.
This makes it a complex operation because space is limited and there are many steps that must be carefully managed. Every change you make influences something else, and that is a major challenge for this project.”
Martin de Ruijter, project manager at Dura Vermeer, added: “This renovation project will allow more trains to operate from the station and accommodate the growth in passenger numbers.
Mammoet’s engineering expertise has proved invaluable, resulting in a solution that has allowed the station to remain operational while the work takes place; minimising disruption to passengers and the city.”