Study on RAM-based Design Indications Impact Analysis for Long-distance block

Long-distance block for conventional and high-speed lines use AF racks for relay to configure one block as several track circuits. This procedure is used to ensure a safe distance when the maximum transmission distance of the AF track circuit is shorter than the train braking distance, and to improve operation efficiency by minimizing unnecessary deceleration in sections at level crossings and curves. The number of AF track circuits and their relaying method, affects design indicators such as long-distance block reliability and operation and maintenance costs. However, domestic railway design guidelines specify only the design indicators that must be applied and do not explain the application specifications and impact analysis methods for each indicator, making it difficult to apply guidelines objectively during design. In this paper, we present a generalized RAM model according to the design method (relay control method, track circuit quantity) for long-distance block. This can help make reasonable design decisions because it is possible to predict operation and maintenance costs considering RAM analysis and operation period depending on the signal and control system design method.