In the high-speed link between Amsterdam and Brussels the rivers Oude Maas and Dordtsche Kil are crossed by means of immersed tunnels. Apart from the bored tunnel ‘Groene Hart’ and a rather short part near the Belgian border, both immersed tunnels are the only sections in the Netherlands where the high-speed railway tracks are not founded on piles, despite the typical Dutch soft soil condition. A long in-depth discussion after contract closure regarding differential settlements and related sectional forces led to very high shear key forces urging to locally widen the outer walls at segmental and immersion joints to combine water tightness gaskets and shear keys. High embankments on top of the immersed elements, the latter founded on weak subsoil layers, resulted in large settlements. Installation of the immersed elements at a higher level and by this compensating for the expected settlements was adopted. Measures to speed up the consolidation process were taken, and postponed shear key installation was implemented to reduce shear key forces at the immersion joints. At the connection with the piled cut and cover sections a transition plate was designed to enable the slab track railway concept within allowable deformations.The small internal cross section of the tunnel bores and the high speed of the trains (300 km/h) would cause sonic boom effects for the voyagers. Therefore, pressure relief shafts were designed on top of the tunnel roof slabs. Where these relief shafts were designed on top of the immersed tunnel, but in the riverbanks, the seasonal longitudinal deformation of the tunnel could result in the failure of the rigid connection between pressure relief shafts and tunnel roof slab. Therefore, a solution was designed comprising rigid air relief shafts, connected watertight to the roof of the tunnel elements, within ‘sliding’ soil retaining shafts. The installation of the soil retaining shafts was part of the marine activities.Due to the low available soil cover on the Dordtsche Kil tunnel at the actual river section, a falling/dragging anchor protection was provided using precast concrete damping slabs.