While at the top of the Mělník hill, from which the castle of Jiří Lobkowicz and especially the tower of the church of St. Peter and Paul, people from a wide area celebrate vintage, just below it, on Saturday, after lunch, another celebration of one completed modernization took place for almost two billion crowns.
Thanks to her, the largest Czech ship Florentina was able to sail from Mělník towards Prague for the first time without any restrictions. After almost three years, the Directorate of Waterways of the Czech Republic has completed a demanding and somewhat unique project to increase a total of seven bridges on the ten-kilometer lateral canal Vraňany – Hořín, including the technical monuments of the Hořín Lock.
“After more than 100 years, the Vraňansko – Hořínský canal has seen modern bridges. We are pleased to have been able to participate in this modernization, which will allow large ships to pass through and at the same time improve the quality of road transport, “says Petr Sodomka, Director of Water Management and Engineering STRABAG Rail, which is involved in the modernization, on the occasion of Saturday’s ceremonial voyage.
The completion of the project will be an opportunity for the development of not only tourist but also freight transport on the Vltava waterway from Prague to Germany, or the opposite route. While large cruise ships on their way from Germany to Prague have so far had to moor just below Mělník, because they could not get further due to the low underpass height of the bridges on the canal between Vraňany and Hořín, today they can continue straight to the Czech capital.
“Technically or correctly, it was definitely not a routine construction,” adds Štěpán Dvořák, the main construction manager of Colas CZ.
The Vraňansko-hořínský canal has been in operation for 116 years. It was opened during the Habsburg monarchy and was one of the greatest technical works of its time. Since then, the ten-kilometer canal has bypassed the Vltava section between Vraňany and Mělník, which is one of the most difficult parts of the Vltava below Prague. And due to its frequent shoals, it was and still is navigable for ships.
There are a total of seven bridges on the side canal, plus bridge decks in Hořín, which overcome a slope of up to nine meters. And it was these in recent decades that have prevented the passage of the largest cruise and cargo ships, because the entire canal was in its time built mainly for low cargo tugs.
Even so, it was difficult to navigate the bridge decks. The tug captains had to retract their bridges and have a limited view, some ships even had to disarm.
And currently the ships were not able to squeeze into the underpass parameters in the form of 4.5 meters maximum height above the surface, so in March 2019, the RVC CR began to modernize the canal. Its main part was the increase of seven bridges to the underpass level of at least seven meters and also the extension of the width of the chambers from eleven to twelve meters.
The canal, which is more than two meters deep, begins with the chambers in Vraňany and ends with the technical monument of the Hořín Lock, behind which water flows from the Vltava canal into the Elbe under the Mělník chateau.
It is a place that tourists looking from the Mělník viewpoint into the distance of the Elbe lowland often intertwine with the right confluence of the two largest Czech rivers, which are located only a few hundred meters further upstream. Even so, it is rather hidden from their eyes.
And it was the Hořín Locks that represented the great technical problem of the entire modernization. The locks were designed at the beginning of the last century by the Czech architect František Sandler, whose buildings (including the locks at Prague’s Štvanice or the power plant at the Hučák weir in Hradec Králové) resemble ships, lighthouses or harbors in their shapes.
Today, the Hořín locks are a cultural and technical monument, and the modernization had to take place with the utmost sensitivity so as not to change the architectural appearance of the chambers.
But how to raise the height of a historical monument and not change its appearance? A technical uniqueness was created, in which at first glance the “secret” hydraulic cylinders, which, if necessary, raise the lock bridge to a minimum underpass height of seven meters, play a major role.
In practice, this meant that the builders had to dismantle the bridge stone by stone, insert hundred-ton pistons under the stone arch of the bridge deck and then carefully return the individual stones and tiles to their original place.
The character of the historic chambers will not change in the basic position of the bridge deck, which together weighs 400 tons. That is, until the large ship arrives and the bridge deck begins to raise the pistons at the command of the control tower.
“The stone arch, which is indistinguishable from the original, will be lifted by hydraulic cylinders by five meters in 6 minutes,” said Lubomír Fojtů, director of the Directorate of Waterways of the Czech Republic.
“We have gone a long way in this construction in this respect, creating a unique work that not only benefits transport, but also has the potential to become a popular tourist attraction,” adds Jan Prokeš, project manager from Metrostav.
As part of the modernization, three more drawbridges have appeared on the entire lateral canal, one of which is a railway bridge. All of them are remotely controlled from the control tower of the Hořín chambers.
Several companies participated in the whole project. In addition to Metrostav, Sudop Prague, Strabag Rail, Eurovia CS, Colas CZ, FIRESTA-Fišer and OK Třebestovice.
The investor was the Directorate of Waterways of the Czech Republic. The total cost of the project, which was co-financed by the EU through the Connecting Europe Facility CEF and the State Fund for Transport Infrastructure, climbed to 1.8 billion crowns.
The flooding of the canal can have a major impact not only on the development of tourist transport between Prague and Mělník and further downstream in Germany, but also gives the opportunity to use the ecological transport of goods by river.
In Mělník, there is a large port from the empire of the Czech Ports of the entrepreneur Miloslav Černý, where today in containers arriving on the Elbe, tens of thousands of tons of goods are transferred to trucks and trains every year.
From Saturday, modern large ships will easily reach the port of Holešovice in Prague and excursions even further, because at the same time as the bridges on the Vraňansko-hořínský canal are being modernized, other bridges between Prague and Vraňany and the chamber on Prague’s Štvanice are being modernized.
However, the Achilles’ heel of the Vltava-Elbe route from Prague to Germany still remains a section on the lower Elbe near Děčín, which is navigable due to the lack of water for most of the year. It could be solved by a new weir, the construction of which has been going on for many years, but due to disputes about the impact on the environment, it is still only on paper.