Complex sentence: Separate parts of the Maastunnel were built elsewhere in a dry dock, and then floated into place and sunk into a trench dug in the river bottom, a technique used in many other Dutch tunnels after the Maastunnel.
Split into simpler sentences: Separate parts of the Maastunnel were build elsewhere in a dry dock, and then floated into place and sunk into a trench dug in the river bottom. A technique used in many other Dutch tunnels after the Maastunnel.