Arlberg Railway Tunnel

First opened to traffic in 1884, it was a major engineering achievement of the nation, being the longest railway tunnel in Austria for over 100 years, possessing a length of 10,216 metres (6.348 mi).

[1] Built at a total cost of 35.5 million gulden, the line had been approved as a single-track railway throughout much of its length; however, the Arlberg tunnel was intentionally constructed with sufficient space to accommodate a double track arrangement from the onset, engineers having anticipated the need to handle higher volumes of traffic than a single line would be able to convey.

A large proportion of the Arlberg Railway Tunnel, akin to much of the line's engineered features, comprised natural stone masonry in its construction, using materials such as limestone, gneiss, and mica schist.

During the early twenty-first century, the Austrian Federal Railways began to reengineer elements of the Arlberg line with contemporary safety features.

[1] As such, the Arlberg Railway Tunnel was subject to a package of works costing 210 million euros during a temporary closure, this included the addition of eight new evacuation and rescue passaged between it and the adjacent Arlberg Road Tunnel; other safety-related changes included a water supply (for fire-fighting purposes), new orientation lighting, emergency telephone and radio facilities, and overhead line disconnection functionality.