Night train from Karlsruhe to Koblenz
There currently is one option to travel by night train from Karlsruhe (Germany) to Koblenz (Germany), taking between approximately 2 and 3 hours: Namely the NJ 402 operated by ÖBB.
The Austrian Federal Railways (ÖBB) operate the Nightjet and Euronight trains (the latter together with other national railway agencies). The ÖBB usually offer three types of carriages in their night trains: seats, couchettes, and sleepers. Seats are for the bravest, while couchettes and sleepers provide a more comfortable journey. Couchettes can hold up to six people, whereas sleepers are private compartments for one to three people. They may include a private bathroom or shower, or sometimes just a sink.