This inter-regional rail line is an extension of the earlier proposal to upgrade the 60-km line Subotica – Sombor. That line connects to the Subotica – Szeged line, which is part of the proposed east-west high-speed route Baja – Subotica – Szeged. These lines would be upgraded to the standards of the German Ausbaustrecken, for 200-230 km/h.
On the diagram: proposed high-speed lines in blue, inter-regional lines in dark green, regional lines in light green, Sombor – Vinkovci options in red. Not all lines are shown.
Note that there is a later alternative for the proposals described here: a direct line Sombor – Osijek via a Danube bridge at Apatin.
The old Szeged – Subotica – Sombor lines form part of a longer rail route, the Alföld – Fiume line. It was built in 1870, as a single line from Oradea to Osijek, for traffic toward the port of Fiume (now Rijeka). At the time the entire line was in the Kingdom of Hungary: it is now divided between Romania, Hungary, Serbia, and Croatia. The line was at right angles to the radial lines from Budapest, which were also cut by new borders.
A Sombor – Osijek link was an integral part of the Alföld – Fiume line, but it was not a straight line, like much of the route. The Danube floodplain here is very wide, and uninhabited. The line turned south, to cross the Danube at Erdut. At first that was by wagon ferry – a bridge was not built until 1910. The line then ran west, parallel to the Danube and Drava, to Osijek.
The line is 61 km long. It is numbered line 20 in Serbia, to the Danube bridge, and then Croatian line R104, as far as Dalj. From Dalj to Osijek, it is line R202.
The line proposed here is a modern version of this link. It would not run to Osijek, which has a relatively isolated position in the rail network, but to Vinkovci, 30 km further south. It would therefore restore the function of the original Dalj – Vinkovci line, built in 1878.
Vinkovci is a classic rail junction: much more so with the proposed Drava plain high-speed line from Vienna, a high-speed line (HSL) from Zagreb, a rerouted line from Sarajevo via Samac, a HSL from Pécs via Osijek, and a completely new HSL to Novi Sad via Vukovar.
There are several possible alignments between Sombor and Vinkovci, all of them using some existing rail lines, including the rest of local line R202, Osijek – Vukovar. The main issue is where the line crosses the Danube. The wide floodplain at the Drava confluence is still an obstacle, and most of it is now a national park. One possible alignment, via Vukovar, would avoid it entirely.
The simplest option is to upgrade the existing lines, with a short new link toward Vinkovci. The alignment on the west side of Sombor, where it turns south, would be improved (new curves shown in red). The line south past Prigrevica and Sonta is almost straight anyway. The old railway bridge at Erdut would be replaced, and the curves into the approach tracks widened (in red on the map).
Click to enlarge: The original railway geography, and new alignments. The base map is an Austro-Hungarian military map of around 1910, without present borders, and with old Hungarian and German place names.
The line to Dalj is straight, and so is the line south to Borovo, but the line turns 90° between them. A wider curve, cutting a small part of Dalj, is the solution. The station for Dalj (population 4500) would be on the north side of the village, to allow interchange with services to Osijek.
At Borovo, there is another sharp curve, where the existing line (here M601) turns toward Vinkovci. The upgraded line could go straight on here, and then curve south-west, to join the proposed HSL from Novi Sad to Vinkovci.
Click to enlarge: The original railway geography at Vukovar, with the proposed HSL Vinkovci – Novi Sad, and the link curve to Borovo, in red.
The pattern of services would be simplified:
- inter-regional service Sombor – Dalj – Vinkovci on the upgraded line
- regional service Sombor – Dalj – Osijek, the existing route across the Danube
- regional service Osijek – Dalj – Odžaci – Novi Sad
- regional service Osijek – Borovo – Vukovar (no interchange at Dalj with the other three services).
Regional services on the existing Borovo – Vinkovci line (Croatian line M601), might be abandoned. The proposed HSL Vinkovci – Vukovar – Novi Sad would carry almost all traffic Vinkovci – Vukovar.
The disadvantage of upgrading the original alignment, even with with better curves, is the zig-zag route via Erdut. The line would be 75 km long.
Click to enlarge: Original alignment in black; HSL and new Borovo curve in orange.
There are two alternatives for this route. One is essentially a cut-off line between Sombor and Dalj, starting on the west side of Sombor. Where the existing line turns south, the new line would go straight on to Apatin, with a new station on its eastern edge. This option is shown as a dashed green line on the maps. It would replace the existing branch line Sombor – Apatin (not on the 1910 map, since it was built later).
Click to enlarge: Original alignment in black/white; Apatin cut-off in green; HSL and new Borovo curve in orange.
The new alignment would then turn south, aligning itself with the Dalj – Borovo line. It would cross the Danube, and join this line. The new section would be about 35 km long. That would create two rail lines, almost at right angles: there would be a new station where they crossed. (The best place is beside the existing station, north of Dalj). The line would continue to Vinkovci via Borovo, as described above.
There is however a ridge north of Dalj, parallel to the Danube (Daljska planina). It is not very high (100 m above the plain), but the line would need a 2500m tunnel – and an 800m bridge, and a 2500m viaduct over the flood plain. This variant would however shorten the route by 10 km, and also serve Apatin. There would be only three services: Sombor – Dalj – Vinkovci, Osijek – Dalj – Odžaci, and Osijek – Vukovar.
The third option would re-route the Sombor – Vinkovci route via Vukovar. Trains would use the existing line south from Sombor. Instead of crossing the bridge at Erdut, they would continue south over a new line, passing Vajska. Near the Danube it would join the proposed HSL from Novi Sad. Trains would cross the Danube into Vukovar, serving the HSL station there, and then continue for 16 km to Vinkovci.
Click to enlarge: Original alignment in black/white; HSL and new link in orange.
The total route Sombor – Vinkovci would be 70 km long. The new section could be built for high speeds. In fact that is the only logical option, for a straight line across a flat plain, with no stations. The line would not serve Dalj, and would not connect with other services.
That undermines the logic of this variant, because there is a simpler alternative. A link west of Odžaci could connect the two proposed high-speed lines to Novi Sad – from Budapest via Sombor and from Zagreb via Vinkovci and Vukovar. The link line would be about 25-35 km long, depending on the alignment. This HSL route Sombor – Vukovar – Vinkovci (passing Odžaci), would be about 80 km long, but journey time would be shorter, However, trains from Subotica could not use it without reversal.
Of the options described here, the shortest is through a tunnel under the Dalj ridge. The construction of a new viaduct, bridge and tunnel might however outweigh its advantages. In that case the upgraded original alignments are the best option. (The later proposal for a direct line via Apatin avoids these issues, but the price is a new line across a nature reserve).