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