Replacement of the collapsed footbridge in Troja took three years, the collapse is being addressed by the court

Prague – Selection of information about the Troja footbridge (a new footbridge is likely to open today, replacing the original structure that collapsed in December 2017):

- The footbridge that connected Císařský Island with Troja for over 33 years collapsed on the afternoon of December 2, 2017, injuring four people, two of them seriously. Regarding the cause of the collapse, corrosion of the supporting cables hidden within the structure was most frequently mentioned. Three weeks after the collapse, a ferry partially replaced the footbridge, which will now be replaced by a new footbridge.

- Construction of the new footbridge began in November 2019. In April this year, builders completed the foundation for the footbridge and all five pillars, starting to install the bridge deck in early June. In August, they mounted the supporting steel structures and began assembling the wooden parts of the deck and railings. The footbridge, costing 150 million crowns, is both wider and taller than the collapsed one. It is 256 meters long and four meters wide, allowing not only walking but also rollerblading or cycling. An ambulance can also pass through it if necessary.

- The old footbridge was constructed using the so-called prestressed structure, where, for example, cables are encased in concrete. The new footbridge features an arch continuous beam made of steel profile with a pipe diameter of 913 millimeters. During a flood, eddies will not form around its pillars. It also has foldable railings that allow water to flow over more easily if necessary.

- The collapse of the footbridge was addressed not only by the city, which compensated the injured with 50,000 crowns (additional compensation in an undisclosed amount was paid by the insurance company), but also by the police. In March, they charged the designer of the footbridge, Jiří Stráský, and the manager, the former head of the bridge department of the Technical Administration of Roads (TSK), Antonín Semecký, with endangering the public through negligence. The indictment was filed this February, and the court began examining the case in mid-September. Both defendants deny the charges.

- Representatives of the Czech Chamber of Authorized Engineers and Technicians in Construction (ČKAIT) also stated in June this year that the charges against the designer and manager are debatable. According to them, the designer has no means to influence the operation and maintenance of the structure. The manager of the bridge must generally rely on the results of other experts’ work.

- The collapsed footbridge was opened on July 7, 1984, at a location where a ferry previously operated (replaced in winter by a pontoon bridge) and in the mid-1970s a military assembled footbridge for pedestrians. This bridge was seriously damaged in summer 1977 by a ship washed away during floods, and there was a ban on entry, which locals largely ignored. The bridge in this condition is seen in one episode of the series "30 Cases of Major Zeman" (Rukojmí v Bella Vista). In July 1981, the damaged bridge was swept away by another flood.

- The same construction and the same author as the footbridge in Troja was also used for the crossing over the Elbe River in Nymburk from 1985. Less than two weeks after the collapse of the Prague footbridge, Nymburk’s management closed the construction, and since June 2018, no ships have been allowed to pass beneath it. River traffic was resumed after two months, during which the footbridge was demolished. Since September 2018, a ferry has been operating in Nymburk. The design for the new footbridge was prepared by SHP - Stráský, Hustý & Partners. The designer is again Jiří Stráský, and the footbridge is expected to be completed next year.

- According to a document prepared last year by experts from the Klokner Institute of the Czech Technical University, there are 275 bridges in the capital classified as so-called prestressed bridges (similar construction to the Troja footbridge). More than half of them are not in good condition. One of the problems with prestressed bridges is the corrosion of cables. The oldest bridge on the list is a nine-meter crossing in Folimanka from 1952. Its supporting structure is in poor condition. Conversely, the youngest is the approximately two-year-old Waltrovka Footbridge, which is in excellent condition.