>>1072485Until the tunnels and bridges were complete, JNR (and later JR) actually had quite an impressive vessel fleet. This class of ships was among the last retired as the Seikan Tunnel was completed, but until then they shuttled trains between Honshu and Hokkaido.
https://ja.wikipedia.org/wiki/%E9%9D%92%E5%87%BD%E9%80%A3%E7%B5%A1%E8%88%B9