  Railway operations require control systems to ensure safety and efficiency,
and to coordinate infrastructure elements such as switches, signals and train
protection. To compete with the traditional approaches to these systems, a
blockchain-based approach has been proposed, with the intent to build a more
resilient, integrated and cost-efficient system. Additionally, the developed
blockchain-based architecture enables to run safety-relevant and
security-focused business logic on off-the-shelf platforms such as cloud,
rather than on specialized (and expensive) secure hardware. After implementing
a prototype of the blockchain-based railway control system, scaling the
approach to real-world mainline and branch operations required a thorough
validation of the design choices. In this technical report, we show how
performance calculations, long-term technology perspectives and law-mandated
norms have impacted the architecture, the technology choices, and the
make-buy-reuse decisions.
