page_title: Plaue–Themar railway
section_title: Operational characteristics
hierarchical_section_title: Plaue–Themar railway / Ilmenau–Schleusingen (Rennsteigbahn) / Operational characteristics
caption_attribution_description: Deutsch: DR-Baureihe 118 (Unterbaureihe 118.2-4) bei Stützerbach 1994
context_page_description: Plaue–Themar railway is a 62 kilometre-long, single-track, non-electrified, standard-gauge branch-line in the Thuringian Forest in Germany. The Stützerbach–Schleusingerneundorf section was built as the first Prussian rack railway between 1879 and 1904 and connects the Erfurt–Schweinfurt railway in the north via the towns of Plaue, Ilmenau, Schleusingen and Themar with the Eisenach–Lichtenfels railway in the south.
  It is divided into three sections: the northern section from Plaue to Ilmenau is currently operated once an hour by Erfurter Bahn, the steep section in the middle from Ilmenau to Schleusingen, which originally contained stretches of rack, and the southern section from Schleusingen to Themar. There is occasional freight traffic on the southern section.
context_section_description: The route is one of the steepest adhesion railways that is still in operation in Germany. The maximum gradient is 6.12%. Until 1927, the line was partly operated using rack and pinion and was thus the first rack railway of the Prussian state railways. Toothed bars using the Abt system with two bars were laid on several sections:
  between Stützerbach and Rennsteig station for 2.12 kilometres (line-kilometre 30.81 to 32.93) at a gradient of 6.01%
  between Rennsteig and Schmiedefeld am Rennsteig for 1.2 kilometres (line-kilometre 33.93 to 35.13) at a gradient of 5.44%
  between Schmiedefeld and Thomasmühle for 1.18 kilometres (line-kilometre 35.76 to 36.94) at a gradient of 5.78% and 1.05 kilometres (line-kilometre 37.88 to 38.39) at a gradient of 6.06%
  between Schleusingen-Ost and Schleusingen for 0.75 kilometres (line-kilometre 49.24 to 49.99) at a gradient of 6.12%
  The Prussian T 26 class steam locomotives always had to face the valley on the rack sections. Therefore, these trains had to have an assisting locomotive to push them uphill. In order to avoid the locomotives having to run around in Rennsteig station, where trains had to reverse, the locomotives were always placed with the chimney towards the mountain. This procedure ensured that the boiler water on the steep rack sections always stood at a sufficient height above the ceiling of the firebox.
  Soon, the company was looking for alternatives to the staff and cost-intensive rack railway operations (which with the maintenance of the Prussian T 26 rack locomotives and the toothed rack sections, particularly in winter, were complex and expensive). As early as 1923, both class 94.5–17 and class 95 locomotives were tested. However, the class 95 locomotives proved to be too heavy because they damaged the rail track superstructure. The experiments with class 94.5-17 locomotives however proved satisfactory and thus the changeover to adhesion operations occurred in 1927 with steam locomotives that could operate on the rack sections (with Riggenbach counter-pressure brakes), which now also hauled the trains while facing uphill because of the comprehensive introduction of fail-safe air brakes and more powerful locomotives.
  From the 1950s, the traveling coaches were mostly reinforced by a second double-decker section. From 1971, six-axle diesel locomotives of DR  class V 180 (class 118) were used, which were able to haul a load of 155 t over the steepest gradient. The journey time on timetable route 622 was at least 70 minutes for the 32 kilometres between Ilmenau and Schleusingen. From 1995 onwards it was operated with class 213 locomotives.
  On the steep slopes, the locomotives always required three independent braking systems. In the summer of 2006, Rennsteigbahn operated trials with class 612 (RegioSwinger) and class 650 (Regio-Shuttle) diesel multiple units, in particular to test the braking systems of these sets and their ability to handle steep grades on the line. Since the beginning of 2007, RegioSwinger sets have been able to operate to Rennsteig. On 24 March 2007, the 612 176 set first ran the line as a non-public special train to prove its suitability for Rennsteigbahn. DB Regio class 612 sets ran on the line as special excursions for the public in January 2011. The Federal Railway Authority (Eisenbahn-Bundesamt) finally granted approval for the operation of Erfurter Bahn's Regio-Shuttles on the steep grades without additional modifications on 24 January 2014 after it had been drafting a new set of rules for several years.
caption: A train near Stützerbach in the winter of 1994
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