  Conventional railway operations employ specialized software and hardware to
ensure safe and secure train operations. Track occupation and signaling are
governed by central control offices, while trains (and their drivers) receive
instructions. To make this setup more dynamic, the train operations can be
decentralized by enabling the trains to find routes and make decisions which
are safeguarded and protocolled in an auditable manner. In this paper, we
present the findings of a first-of-its-kind blockchain-based prototype
implementation for railway control, based on decentralization but also ensuring
that the overall system state remains conflict-free and safe. We also show how
a blockchain-based approach simplifies usage billing and enables a
train-to-train/machine-to-machine economy. Finally, first ideas addressing the
use of blockchain as a life-cycle approach for condition based monitoring and
predictive maintenance in train operations are outlined.
