Few railways can boast as many superlatives as the Jizera Mountain – Giant Mountain railway line from Tanvald to Harrachov which can be found in the timetable under number 035. It is not only interesting thanks to its unique construction, but also thanks to its rich history. The Tanvald - Kořenov section was declared a cultural monument by the Ministry of Culture of the Czech Republic in 1992.
The line was built in 1899-1902 as an important link between the industrial areas of Liberec and Jablonec and the western area of Silesia, the most significant centre of which was the town of Hirschberg (now Jelenia Góra). Operations on the Tanvald–Kořenov line officially commenced on 30th June 1902. The line became a significant connection for the exports of textile products to Prussia and for the import of high quality Upper Silesian coal and raw materials for glassworks. The commenced electrification of the line on the Prussian side was held up by the First World War and so the first electric train arrived in Kořenov (known as Polubný at that time) from Prussia on 15.2.1923.
While the transport from Kořenov to Silesia was secured using modern electric locomotives from Prussia and later from the German Reich, Austrian Class 404.0 steam rack and pinion locomotives from Floridsdorf were operated on our side of the line. During the Second World War, the Germans also began to operate steam locomotives without a rack and pinion system (adhesive operations) on the rack and pinion section of the line to Tanvald and maintenance was generally neglected. 1945 was a fateful year for the entire Jizera Mountain – Giant Mountain railway and it saw a significant reduction in the line’s importance. Electric operations ceased in May and the international railway crossing into the Polish Republic was definitively closed in November of the same year. Necessary reconstruction work took place on the Tanvald - Kořenov line with the cessation of operations from 1958 to 1962 and operations up to the newly built Harrachov Stop commenced on 26th May 1963. Austrian T 426.0 (nowadays Class 715) rack and pinion locomotives gradually replaced the Class 404.0 steam veterans on our side of the line as early as in 1961. Class M 240.0 (now Class 820) motor coaches were used for passenger transport on the line from 1964 and the Class T 426.0 (715) rack and pinion locomotives were used for pulling freight trains up to the end of the 1980s. The section from Kořenov to Harrachov was reconstructed at the beginning of the 1980s. At the turn of 1987 and 1988, the Prague ČKD locomotive works delivered Class T 466.3 (nowadays Class 743) locomotives which had been specially developed for the Tanvald - Harrachov line and its demanding gradients and they initially took over freight transport and later also passenger transport from 1990.
A conspicuous effort to renew the rail connection with Poland occurred in 1991-92. Thanks to the work of volunteers, a train was once again able to travel from the Czech side to Szklarska Poręba after 47 years. The first train was only a work train and it departed on 31st May 1992. In the summer of 1992, passenger trains travelled from Kořenov to Szklarska Poręba at the weekends and on 18th and 19th September trains even travelled the 86 km long line from Liberec to Jelenia Góra. Despite the immense interest among the public, the renewal of regular international travel has not yet occurred, but the idea is still well and truly alive.
1997 became a milestone year in the modern history of the Tanvald - Harrachov line. On 27th September 1997, the former management at Czech Railways halted all passenger transport on the line on the grounds that it was significantly in the red and poorly utilised. The decision was not even overturned by a petition for the preservation of passenger transport on the Tanvald – Harrachov line which had been signed by more than 25,000 people. On 24th May 1998, passenger transport was renewed with a new rail operator, GJW Praha s.r.o., when the Tanvald - Harrachov line, the Liberec - Tanvald - Železný Brod line and the Smržovka - Josefův Důl line were rented by the Jizera Railway Interest Group of Associated Municipalities. The Class 743 diesel-electric locomotives (nicknamed “electronics”) were replaced in passenger transport by Class 810 light motor coaches and the scope of the passenger transport was significantly expanded in comparison with the past. The operation of the rail transport on the originally rented lines returned to Czech Railways from 1.12.1998.