Una line

The Una Line

Introduction

After more than 9 years, the Una line was reopened on 26^th January 2001. The traffic had been disrupted from 8^th August 1991 and from then till the military operation ‘Tempest’ in 1995 the line had been out of official control. Still, there had been some weak local traffic even during that period. Later during the war the line and the signs along it were damaged, so the traffic was completely stopped. Rebuilding, run by the Croatian railways (HZ) helped by SFOR, started in 1998. Considering political and legal changes in these parts of Europe, the line now passes through two states, Croatia (257 km) and BiH (135 km), and is run by three railway companies: the Croatian Railways (HZ) runs the sections zagreb - Sisak - Volinja and Martin Brod - Knin, the Railways of Bosnia and Herzegovina (ZBH) runs the sections Blatna - Bihac - Martin Brod, and the Railways of the Republic of Srpska (ZRS) runs the section Volinja - Blatna. One of the most interesting features of this line is repeated crossing of state borders. For example, the section Martin Brod - Knin (61 km long) crosses the border 7 times, so he traffic will be run according to special international agreements.

History

The first initiative to build the line dates from the second half of the 19^th century, prompted by the enormous potential of many Adriatic harbours. When so called partial line (Split - Perkovic - Siveric and Perkovic - Sibenik, continuing to Knin from 1888) was built in 1873 in Dalmatia, there was a strong initiative for its integration in the railway net. However, the connection with the continental part of the country wasn’t built until 1925 and even then it wasn’t passing through the Una valley, but through Lika (Knin - Gracac - Vrhovine - Plitvicka jezera - Ogulin). The Lika line is built on a rather inconvenient terrain with lots of strong curves and big slopes. Although there are some plans for modernisation of the line, which would include decurving, building new tunnels, and electrification, there has never been any real investment. The first section of the Zagreb - Bihac - Knin line was released in 1882., and it went from Sunja to Novigrad through Volinja. The Novigrad - Bihac section was released in 1924. The problem was whether the last station in Dalmatia should be Knin or Zrmanja. Jerko Alacevic, a professor on the Technical Faculty of Zagreb believed that it should be Knin because the line would avoid all the important buildings. Moreover, the winter climate was much better and so was the terrain configuration. This strong argumentation won and in 1931 the line was officially traced, with Knin as final station. The traffic department made a rather disadvantageous building contract with a French company called Batignol. During the following three years, those in favour of Zrmanja as last station tried to change the line, but it was in vain. The real tracing started in 1935 from Knin and Bihac simultaneously (2x15km). In 1936 light sections started to be built and the initial plans were improved. The 2^nd World War interrupted the construction, so the line wasn’t finished until 25^th December 1948. It was electrified in 1987 (25kV, 50Hz).

Data

The section Bihac (222.59m above the sea level) - Martin Brod - Knin (222m above the sea level) is 113km long. The first 15km of the line south of Bihac passes through the Una valley, and the next 50km closely follows the river. The line crosses 2 bridges over Una, each of them about 70m long. The highest point of the whole line is the Kaldrma station, which is situated at 673m above the sea level. The steepest ascent in the direction of Knin is 20 (13km long) and the steepest descent in the same direction is 23 (18 km long). The overall length of bridges and viaducts, the biggest of which are Krka, Ostrovica, Butisnica, Japada and Vrpolje, is 985m, and the overall length of tunnels is 11820m. The biggest tunnels are Celije, Popov Kuk, and Bjelila. Stations Bihac, Ripac, Loksum, Strpci, Kulen Vakuf, Martin Brod, Radjenovic-Srb, Dugo Polje, Tiskovac, Drenovac, Strmica and Golubic, were built along with the line. The Knin station has been widened because of a rather dense traffic, and the section Novigrad - Bihac has been modernised: there are less curves and road-crossings now and the rails have been replaced.

Destruction and rebuilding

Three bridges on the line were demolished and later rebuilt by SFOR units (the reconstruction was financed by EU). The whole line has been freed from mines (15m from the rails on each side), various damages have been repaired and new signals installed. Unfortunately, electrification hasn’t been repaired up to this day. The line was ready for SFOR trains in 1998. It can handle the axe pressure of 22,5t and the speed of 40km/s. Security devices were destroyed during the war, so trains have to stop before two road-crossings. A higher maximum speed may be introduced with the 2002/02 timetable.

The text is based on various HZ materials published on the occasion of reopening the Una line. We wish to thank the authors of those materials, Mrs. Helena Bunijevac and Vlatka Skoric.