Route , starting point of the line Today's secondary line branches off the Erfurt–Schweinfurt railway in
Plaue. The line climbs 200 metres during the 10 km-long section to
Geraberg. The route followed here does not run through the easier Reichenbach valley, but instead climbs the slope up the valley of the
Zahme Gera. The reasons are historical. There are numerous rocky areas where the terrain is nearly impassable. The line climbs steeply on the western slope of the valley and reaches a height that is about 30 m above the valley in
Angelroda. Here it crosses the valley on a
viaduct, which is followed by a 20 m deep
cutting, where the line transitions from the Gera valley to the
Reichenbach valley. It continues through relatively flat terrain to
Martinroda, which also has a
Haltepunkt (halt), although it is about 2 km from the village. The next place on the line is
Geraberg. The route changes again from the Reichenbach valley to the
Gera valley. The line runs above the village around Mönchsheide hill to
Elgersburg station. In the village there is a cutting that is about 12 m deep, which takes the line from the Gera valley to the Reichenbach valley again. Here it runs relatively directly on the edge of the forest to the southeast towards Ilmenau-Roda. There the high point of the section is reached at an altitude of 515 metres. It then passes through a wide curve, past the halt of
Ilmenau Pörlitzer Höhe (opened in 1995) through the town of Ilmenau down into the
Ilm valley, where
Ilmenau station is located at an altitude of 477 metres.
History Background and construction When the
Neudietendorf–Arnstadt railway reached
Arnstadt, there were increasing demands for railway to Ilmenau. The efforts failed for the time being due to the political fragmentation of Thuringia. The rulers of four Thuringian states had to give permission for a route between Arnstadt and Ilmenau. They had little interest in economic competition with their capital cities along the Leipzig–Weimar–Erfurt–Gotha–Eisenach axis. In addition, transport planners were already forging other plans, like an Ilmenau–
Suhl connection, which would form part of a Berlin–Stuttgart route, and an Ilmenau–
Saalfeld connection. Prussia urged Suhl (which, along with Erfurt, belonged to Prussia) to build a connection to the northern Thuringian foreland to provide an efficient access to the arms industry in Suhl. A further extension of the line via Stützerbach to Suhl, which had already been envisaged by the planners in the early planning phase, was not carried out, since no agreement was reached between the small states of the Thuringian area affected by the line and the construction costs were too high. Under this option, an approximately 2000 m-long tunnel would have been built under the ridge of the Thuringian Forest in the Schmücke/Großer Finsterberg area. When the
Thuringian Railway Company (
Thüringische Eisenbahn-Gesellschaft) proposed in 1876 to continue the line from Arnstadt to Ilmenau, difficult negotiations had to be held with the representatives of the various states. The Duke of
Saxe-Coburg and Gotha Ernst II offered the greatest resistance. The Thuringian Railway Company knew that the Duke liked to stay in
Elgersburg for recreation and they wanted to meet him with a proposal for a route that would start in the valley of the
Zahme Gera and run via
Geschwenda, Arlesberg (which later merged with mid-Thuringian
—mittelthüringischen—Gera to form
Geraberg) to Elgersburg. This plan failed initially due to the resistance of the Duke, who wanted to build a railway from
Ohrdruf to Elgersburg that would have run entirely over his own territory, but also due to massive protests by the citizens of Geschwenda against the railway. The citizens feared that constant
boiler explosions would ravage the country, that the smoke of the locomotives would pollute the air and make the grass bitter and that the cows would give only sour milk as a result of the sight of the monsters—common prejudices in the time, which
George Stephenson also had to fight in England. The planned line running entirely through the
Reichenbach valley and
Martinroda was welcomed there and Martinroda was willing to provide the land for any route through it free of charge. However, this route now failed because of the veto of the Duke of Gotha. Since his preferred route from Ohrdruf to Elgersburg proved too expensive, he had to give it up and now wanted a station in Elgersburg on the Arnstadt–Ilmenau line. His approval for the project was needed because the Arnstadt–Plaue section of the line had to run through his territory. A route from Plaue that only ran through the Reichenbach Valley would not have passed through Elgersburg, but it would have been much cheaper. The Duke's consent was dependent on a large and prestigious station in Elgersburg, which would include permanent additional tracks that would be available for the use of his special trains. The route now required an elaborate and expensive structure in
Angelroda in order to be able to fulfill the promise given to Martinroda, even though Martinroda station could no longer be built in the village and instead had to be built 2 km away from it. The new complex route also avoided touching the area of the municipality of Geschwenda, whose citizens were vehement against the building of a railway. In fact, Martinroda and Geraberg (at that time still called Gera ) provided virtually all the land for the line free of charge. As a result of the new route, Geraberg also now received a station. This is only about 1.1 km in a direct line from the station in Elgersburg, also connected by a direct road, but the railway was difficult to build. It is 1.7 km-long and required an elaborate, deep cutting through rock. In Angelroda support for the 26 m high embankment on the edge of the village, which was now necessary, was anything but enthusiastic, as it was feared that there would be less "good air" coming down from the Thuringian Forest in
down-slope winds. They therefore wanted a bridge that was as long as possible. This would have increased the cost of the project that was now estimated to cost 4,140,000
marks (M) by a further 27,000 M, which the Thüringian Railway Company did not want to raise to benefit farmers in Angelroda. The little village of Angelroda did not have the necessary financial resources to pay for the proposed change, even though this was only a fraction of the cost of the changes required to meet the special demands of the Duke of Gotha. The Principality of
Schwarzburg-Rudolstadt sought a continuation of the line to
Gehren and on to
Schwarzburg,
Rudolstadt and
Saalfeld. There it would have connected with the
Gera–Saalfeld–Eichicht railway opened in 1871. The building permit for the Arnstadt–Ilmenau railway was therefore issued only on the condition that this connection was to be built within 10 years and that the entire line was to be at least prepared to allow a second track to be built. This requirement meant that all viaducts, mountain sections and bridges had to be built significantly larger than originally planned. All stone bridges and the embankment from
Plaue towards Ilmenau across the valley of the Zahme Gera (called the
Sand valley in Plaue), which is 825 m long and up to 8.5 m high, were designed for the eventual laying of a second track, but only the abutments of stone bridges like the viaduct over Angelroda were built for two tracks, while the steel superstructures and pillars were built for one track. The only doubling of the track that was ever implemented was a section built between Arnstadt and Plaue during the construction of the
main line from Plaue via
Oberhof and Suhl to
Würzburg and Stuttgart. As a result of tenacious negotiations, the Thuringian Railway Company was able to conclude treaties with all four Thuringian Principalities concerned. Agreements were signed with
Saxe-Weimar-Eisenach on 16 April 1877, with Saxe-Coburg and Gotha and with Schwarzburg-Rudolstadt on 6 June 1877 and with
Schwarzburg-Sondershausen on 27 June 1877. Tree clearing began in the winter of 1877/78 and the
groundbreaking ceremony was held on 23 April 1878 at Kleine Spiegelsberg, between Roda and Elgersburg. The building was divided into two sections (Arnstadt–Angelroda and Angelroda–Ilmenau) and it was carried out simultaneously in all construction phases. On average, 300 workers were employed in each section. Among them were many workers from Italy, Croatia, Poland and the Tyrol. The pay was 3.50 M to 4.50 M per day in the summer and 2.25 M to 3.25 M per day in the winter because of the shorter days.
Day labourers earned 2.25 M per day. During the construction work, five workers were killed in work accidents, while there were five major and eleven minor injuries. The line was essentially built by hand and was supplied by a
field railway from Arnstadt. The most outstanding achievements were the rock cutting on the approach through a hill to the bridge in Angelroda, which was up to 26 m deep, and the movement of earth for an embankment near Plaue, which was 825 m long and up to 8.5 m high. 90,000 m³ of rock was placed for this embankment below the track and 150,000 m³ of rock was placed above the track bed. The project used a
funicular, which ran on a wooden trestle which had been built for it. Rock was dumped from the funicular down on the embankment. The wooden trestle was left in the completed embankment. Rocks along almost the whole line had to be loosened with explosives. 2,950 kg of
dynamite, 8,810 kg of
black powder and 115,000 percussion caps were used for about 10,000 firings. The line has grades from Plaue of 1:50 to 1:70 and sections with radii of only 300 m as it passes through a genuine mountain range. The largest bridge on the line is the Marien bridge near Plaue. It spanned former federal highway 4 at line-kilometre 15.9. The biggest bridge on the line is the arched viaduct in Angelroda. It is 26.5 m high, 100.4 m long and consists of three spans. 253 t of steel were used for the bridge. It was built in a very innovative way as a projected bridge supported by auxiliary scaffolds. For this purpose, the individual sections of the bridge were mounted on the projections of the viaduct and moved over the bridge piers by being hauled by cable. The position of the entire bridge on a sharply curving track made this bridge construction difficult and also posed a challenge for the designers. A curiosity is also the construction of the retaining walls at the bases of the bridge piers. Here, the supporting walls were not inclined, as is normal custom, but were stepped instead. It is not known why the greater and self-reinforcing stability of a sloped retaining wall was not used. The original steel lattice structures of the two piers were covered in concrete in 1905 to increase their load bearing capacity. In contrast to the steel pillars, the rebuilt concrete bridge piers were again designed to receive the superstructures for a second track that was never installed. On the new, wider piers, a new, stronger bridge was built parallel to the existing bridge and the track was swung onto it and the old superstructure, with the exception of the old bridge deck, which was cast in place, was demolished. Since then the eastern side of the piers has been undeveloped. The masonry structure of the bridge piers is deceptive and has only a visual character. In fact, the pillars are not brick, but are cast in mass concrete.
Later development The Arnstadt–Ilmenau line was opened on 6 August 1879. The continuation of the line from Ilmenau to Gehren was opened on 13 November 1881. The planned extension to
Königsee and Saalfeld, however, was not implemented and a planned continuation to
Stadtilm and
Weimar through the Ilm valley was also not built. Königsee was reached from Rudolstadt by the Schwarza Valley Railway (
Schwarzatalbahn, later considered to be the
Köditzberg-Königsee railway or part of the
Rottenbach–Katzhütte railway) in 1899, but the missing 8 km section to Gehren through geologically easy terrain was never built because of a lack of profitability and this was partly responsible for the later closure of both branch lines. The
line to Gehren was, however, extended to
Großbreitenbach on 2 December 1883. The planned continuation from Grossbreitenbach to Schönbrunn (in the municipality of
Schleusegrund) or
Katzhütte (which the Schwarza Valley Railway reached from Rudolstadt on 18 August 1900) was omitted. Here, in particular, a 7 km-long connection to Katzhütte would have significantly increased traffic on the line, but it failed because of the difficult geology on this route. In the last war days of the Second World War, the bridge in Angelroda was prepared for detonation, although it was completely irrelevant to the course of the war. Citizens of Angelroda, who feared damage to their houses, some of which were next to the bridge, delayed the detonation until the arrival of American troops. During the
Cold War, acts of
sabotage to the bridge were feared. Therefore, it was permanently guarded from 1950 to 1958/59. During the time of the GDR, the line initially had the timetable number of "189d", but since 1968, it has had the number of 622. A general overhaul of the line took place in the summer of 1970. The track and sleepers were replaced, and the railway line was moved to the centre of the formation in places, since doubling of the track was no longer expected. Over several months in 2012/2013, the line between Plaue and Ilmenau was rehabilitated with all traffic operating and the line speed was increased to 80 km/h. Over a two kilometre-long section, adjacent rock walls were secured with a special system of nets. The free steel trusses of the viaduct at Angelroda were lifted with mobile cranes and then repaired. A total of €13 m was allocated for these works. Due to heavy corrosion of the bridge’s superstructure, this could not be completed by the end of October 2012 as planned. The recommencement of services was postponed initially from 19 November 2012 to 16 May 2013. The renovation of the section between Elgersburg and Ilmenau, which had originally been planned to be done separately was, however, brought forward and was also intended to be completed by May 2013. After the reconstruction of the bridge superstructure was carried out in the middle of July 2013, the line was re-commissioned on 11 August 2013.
Accidents and incidents The temperature fell to -38 °C in the winter of 1928/29. This led to several days without operations because of the icing of the water supply, the locomotives and the points on the line. On 9 January 1935, a freight train derailed in Martinroda at the exit towards Ilmenau. Locomotive 94106 derailed and remained leaning on a gradient of about 45°. It was recovered and repaired. Arnstadt locomotive depot was bombed on 6 February 1945. This raid killed 70 forced labourers, who were lodged in barracks near the depot. Shortly before the end of the war a
Lockheed P-38 Lightning strafed a passenger train from Arnstadt at Geraberg killing passengers, including a pregnant woman. German soldiers senselessly blew up still isolated bridges at the end of the war, like the small bridge over the B88 behind Elgersburg. This was replaced on 1 July 1945 by a temporary timber bridge and finally repaired in 1948 by installing a steel structure.
Current operations Today the Plaue–Ilmenau section is served hourly by the
Erfurter Bahn line 46 (Erfurt–Arnstadt–Ilmenau, timetable line 566). Two
Stadler Regio-Shuttle RS1 diesel multiple units (150 seats) are normally used, occasionally
Bombardier Itino sets (120 seats) are also used. Since the timetable change in June 2014, Erfurter Bahn services have run on weekends and holidays to Rennsteig station. Four train pairs run on operating days between Ilmenau and Rennsteig. == Ilmenau–Schleusingen (Rennsteigbahn) ==