Borovnica railway viaduct 1850 – 1944

The Viaduct Construction

The Borovnica Viaduct used to be the largest bridging structure in the Southern Railway route between Vienna and Trieste. This route was of exceptional importance for the former Austrian Empire, since it connected its capital and some important centres of developing industry with the only large seaport in the country. Construction of the Viaduct began in 1850 and ended in 1856. At its narrowest part, the Viaduct spanned over the Borovnica Valley in the length of 561 metres, and its top part was 38 metres high. The Viaduct ran in a curve on both sides, with its central section of about 80 metres running straight. The two-level Viaduct consisted of 24 columns. They were numbered from 1 to 24 following the direction from Ljubljana to Postojna. There were 25 arches, 16.75 metres wide and 15.17 metres high each, between the columns on the upper level, and 22 arches, 15 metres wide and 19 metres high each, on the lower level. The path leading through vaulted holes in the columns on the top of the lower level was constructed for Viaduct maintenance purposes. With the exception of two larger, double columns, the width of each column was 14.70 metres at the ground, narrowing towards the top to just under 9 meters. The width of the two-track line was nearly 8 metres.

In order to provide a solid foundation for the construction, about 4,000 oak piles were sunken into the soft ground, with column foundations built on top. Columns and arches were made of 31,600 m3 of processed stone blocks, 31,000 m3 of crushed stone, and about 5 million bricks. The construction was supervised by the imperial-royal senior civil engineer named Arcari. For the construction purposes, a brickyard was built nearby. Most of stone blocks were brought from the Podpeč quarry, and a few ones also from smaller nearby quarries. One of them was located above the Zabočevo village, and its remains are still visible. Stone blocks were mostly transported by ox-carts operated by local farmers. Stone blocks weighted up to two and a half tonnes (a piece). They were transported by special high carts with large wheels, with a stone mass placed under the cart and lifted off the ground as necessary using screws and nuts. A worked stone piece hung under the cart throughout the ride. In the same way as lifted, the stone was slowly lowered to the ground. According to oral tradition, building materials were transported to a high wooden scaffold by draught animals. Before ascending the scaffold, their eyes were blindfolded to prevent them to be frightened by the height. The foreman had an apron with a large money pocket. Anyone who brought bricks to the scaffold was immediately paid out. Bricks were also carried onto the scaffold by children and women. The Borovnica Viaduct was built without the use of cement.

The stone blocks were connected to each other with iron clamps and these were filled with lead. Both the parapet wall and the fence were artfully and decoratively carved and surrounded by ornaments. The construction took over 6 years with the cost of 2 million florins, which would amount to approximately 30 million euros today.

Measures of  Borovnica viaduct

In its 25th issue of June 1851, the newspaper Kmetijske in rokodelske novice wrote (Agricultural and Artisanal News): “Correspondent from the Carniolan Region. Among such places that will be only put on the map by new times, is Borovnica, beyond Vrhnika, in the corner at the end of the long Ljubljana Moors. Such a railway bridge is being prepared there that has no parallel in any other railway line; it will be over 200 fathoms long, and 19, or according to the most recent information, even 31 fathoms high. A lot of work is required to prepare the foundation, because a lot of piles have to be sunken into the mostly soft base and vegetation before the stones can be laid. The construction will actually cover two bridges, one on top of the other; the stones are therefore already being cut in several places, but in a completely different size than for other structures. When this bridge is completed, Borovnica will be as closed as if it were separated from the world; and passengers will watch it from above like a bird flying by. A little further from this big bridge, preparations are ongoing for another bridge, which will not be much lower than the first one, but much shorter. So far, there are about 3,000 workers engaged in work on the entire route from Žalostna gora to Vrhnika; and there will have to be more of them if the work is to be completed soon.”

Novice newspaper followed the progress of the Viaduct construction and published in its 42nd issue in May 1854 the following: “Correspondent from Austrian regions. In Vrhnika, 21 May. H. What does the railway say in our pages? Is the work accelerating? The main thing here is the big bridge (viaduct) in front of Borovnica; the columns of the lower section are all completed as if cast, they are so beautifully and smoothly carved out of stone. The brickwork is already rising on all of them and curving to arches, where one of them is already closed, and two are almost completed. The bricks for this bridge are, however, specially prepared, they are not of the same thickness, but look like a wedge, thinner at one end. On the lower section columns, between the arches, there are columns erected for the upper section, they are cut out of stone as the lower ones, and the arches on them will also be made of brick. In the middle between the lower and upper sections, a road for ordinary carts will be open and lead to the railway station from the other side. The other two major bridges in this side are also being diligently constructed; namely, in one, in Doli before Borovnica, some columns are already built almost up to the top and some to the middle; and the second bridge, in Blatni dol across the old road above Vrhnika, will be completed in a few weeks.”

The test drive from Ljubljana to Borovnica was made on 28 October 1856, just before the arrival of Emperor Franz Joseph. He travelled across the Viaduct during his visit to Postojna Cave. In its 247th issue, on 22 October 1939, Jutro newspaper published on page 7 an article on the fate of the Borovnica Viaduct, and wrote, among other things: “Everything was in green, and thousands of lights were lit on the parapet walls, having a fabulous effect on the huge stack of walls in the evening.” The Emperor repeated the ride in July 1857, when he travelled to Trieste at the opening of the Southern Railway.

The construction was carried out with inhuman efforts, using rather primitive means compared to today’s options. Nevertheless, in 1856, when the first train passed it, the Viaduct was a real technical and architectural masterpiece. On 30 August 1856, an Austrian correspondent wrote in Bleiweisove novice (Bleiweis’s News): “The last arch of the 20-and-a-half-fathom high and 280-fathom long stone-block railway bridge in Borovnica – Franzdorf – which is said to have no equal in Europe – was completed on the 18th day of this month.” This was his announcement of the completion of the Borovnica Viaduct, one of the largest railway viaducts in the then Europe.

In addition to the Borovnica Viaduct, four smaller ones were built in the immediate vicinity: the Pako Viaduct, Breg Viaduct (today: the Pako Bridge), Jelenova dolina Viaduct, and Dol Viaduct. A railway station, including an engine shed, a turntable, and other auxiliary facilities, was built on the plateau between the Borovnica Viaduct and the Jelenova dolina Viaduct. At the beginning, only a few trains ran through Borovnica, the first stop after Ljubljana, and their weight brought no significant burden to the Viaduct.

Borovnica basin, 1857. Source: Borovnica Historical Society

Borovnica viaduct, 1857. Source: Borovnica Historical Society

Upper level of Borovnica viaduct, 1857. Source: Borovnica Historical Society

Johann Bosch

He was a factory-owner and later an amateur photographer, active in 1841–1865. As a travelling daguerreotypist from Vienna, he worked in Graz in 1841, then in Zagreb, and in May 1842 in Trieste, where he was one of the first photographers. At the beginning of July of the same year, he arrived in Ljubljana. He had images of architecture and landscapes on display. He set up his temporary studio in Poštna ulica. He charged his customers 5 guldens for portraits and 2 guldens per person for group photos. An advertisement for his studio was published in Carniola newspaper.

In 1844, he returned to Graz, where he had his studio on Schöngelgstrasse 446. He was a landscape photographer known for Views from Steinmark. Until April 1861, he was a member of the Photographic Society of Vienna. In 1864, he took part in the “First Photographic Exhibition of Vienna” organised by the Vienna Photographic Society. His photo called the Source of Ljubljanica near Vrhnika is included in the catalogue of this exhibition.

He took photos with a Voigtlander camera, the best camera in the world at those times. It was equipped with Petzval lenses. He used daguerreotype, calotype and ambrotype procedures, and was one of the first photographers using the collodion procedure.

Viaduct Pako, 1857. Source: Borovnica Historical Society

Viaduct Breg, 1857, Source: Borovnica Historical Society 

Deer viaduct (Jelenov viadukt), 1857. Source: Borovnica Historical Society

Viaduct Dol, 1857. Source: Borovnica Historical Society

In 1855 and 1856, he took photos of the Southern Railway construction. His photos were given as present to Kaiser in a nice box on 20 November 1856, when he took a train from Ljubljana to Postojna. The box contains ten photos of the Southern Railway construction: six photos of the Borovnica Viaduct construction, a photo of the Jelenova dolina Viaduct, a photo of the Štampet Viaduct, a photo of the Postojna Railway Station construction, and a photo of the sinkhole near Postojna Cave.

These photos were most likely taken on a glass plate and properly processed, as they should be for a gift to the Emperor. Three photos have the author’s signature. We believe that Johann Bosch also authored nine photos of the Southern Railway viaducts obtained by the Borovnica Historical Society at the opening of the Guardhouse No. 666. Given their format and the method of make, it is believed that the photos were intended for persons of significance. This series contains the oldest photo of Borovnica till now.

From Vienna to Ljubljana

In the 1930s, the railway reached European territory…


At that time, Borovnica, a small village in the southern part of the Ljubljana Moors, had about fifty houses…

The life of Viaduct

The railway line over the Borovnica and other viaducts was insulated with compacted clay…

The Second World War

On Easter Thursday, 10 April 1941, at five o’clock p.m., the Borovnica Viaduct was blasted under the command of Captain Žužek…

The construction of a new line

Borovnica was liberated on 6 May 1945, when it was entered by units of the 29th Herzegovina’s Strike Division…


This website is a part of the project »Thematic Park and Memorial Path of Borovnica Viaduct«, co-financed by the European Fund

for Regional Development (EFRD) throught the Local Action Group Barje z zaledjem.