Why does a rack-and-pinion railway have teeth?

The Jizera Mountains-Krkonoše Mountains railway line on the Tanvald – Kořenov – Harrachov route is the steepest and the only standard gauge rack-and-pinion railway in the Czech Republic. Thanks to its Abt pinion rack system, the trains can overcome a gradient of 235 metres over the almost 7 kilometres between Tanvald (466 m above sea level) and Kořenov (701 m above sea level). The three steepest sections with a total length of 4.4 km include toothed strips in the tracks which assist the rack-and-pinion trains to overcome the greatest gradient with a value of up to 58 per mille. This is possible thanks to an ingenious system, whereby the locomotive’s cogs click into the teeth of the toothed strips.

The construction of this mountain track in the summer of 1902 required the construction of 4 tunnels, many cliff cuttings and the construction of several bridges. The route continues across the 25 m high Jizera Viaduct from Kořenov, an S-shaped tunnel leads to Harrachov and the track then heads through the Novosvětský Pass (886 m above sea level) towards the Polish towns of Szklarska Poręba and Jelenia Gora. The route offers many views of the Jizera Mountains and the Krkonoše together with the highest Czech mountain, Mount Sněžka (1602 m above sea level).

The entire railway was built to connect the Upper Silesian coal basin with the industrially developed town of Jablonec. The operations on the rack-and-pinion railway were provided by a series 404.0 cog locomotive from the Austrian locomotive works in Floridsdorf, while the operations on the Polish side were secured by regular steam locomotives and electric railcars. The most significant was the ET89 Krakonoš (Rübezahl) which pulled direct express trains to Kořenov (formerly Grünthal) from distant Wroclaw. After World War II, the international operations were suspended. In the 1960s, the track was reconstructed and new T426.0 Austrian motorised cog locomotives and Czech series M240.0 motorised railcars began to operate on the section from Tanvald to Kořenov. The regular rack-and-pinion operations ceased in 1988 and the Austrian locomotives were replaced with new series 743 locomotives which did not require the toothed tracks. 

Nowadays, regular operations are provided by modern non-rack-and-pinion motorised railcars. 

Polish Railways renewed the railway operations from Harrachov to the Polish towns of Szklarska Poręba Górna.

In 1992, the rack-and-pinion railway was declared a cultural monument; it is a popular attraction in the region.