Einspulige

"Einspulige" is a term primarily used in German-speaking regions to describe a type of single-track railway line, often found in mountainous or rural areas where constructing a double-track line is impractical due to cost, terrain, or traffic volume. The name derives from the German phrase "ein Spule," meaning "one track," as opposed to the more common "zweispurige" (double-track) lines.

Single-track lines like these are designed to accommodate trains traveling in both directions by using a system of passing loops, sidings, or junctions. These features allow trains to bypass each other when necessary, ensuring efficient operation. In densely forested or steep mountainous regions, such as the Alps, single-track lines are common due to the difficulty of constructing multiple parallel tracks. They are also frequently found in heritage railways, where maintaining a double-track system would be economically unfeasible.

The operation of einspulige lines requires careful scheduling and coordination to prevent conflicts between trains. Stations along these routes often feature passing loops, where trains can wait for their scheduled departure time or for an oncoming train to pass. Some lines also use a system of block signaling, where trains are only allowed to proceed when the next section of track is clear, further enhancing safety.

While einspulige lines may have lower capacity compared to double-track systems, they remain an essential part of many regional and freight rail networks. Their use is particularly notable in countries like Germany, Austria, and Switzerland, where mountainous terrain has historically influenced railway infrastructure development. Modern advancements in signaling and automation continue to improve the efficiency and reliability of single-track operations.