Centralbron

Centralbron viewed from Södermalm. In the background from left to right: Stockholm City Hall, Riddarholmen, and Gamla stan.

View southbound from Riddarholmsbron.

Centralbron (Swedish: "The Central Bridge") is one of the major traffic routes in central Stockholm, Sweden, connecting the northern district Norrmalm to the southern Södermalm. It is 1,200 metres long and consists of two viaducts passing over Söderström ("Southern Stream") and Riddarfjärden close to Norrström ("Northern Stream") with an interjacent elevated section traversing Riddarholmskanalen and the adjacent eastern water front of Riddarholmen. Centralbron have a capacity for 130,000 cars per day. It is paralleled by the bridges (Södra and Norra järnvägsbron) and the tunnel of a two-track railway used by the commuters and freight trains.

Over the years, Centralbron together with a suggested additional railway track have been much criticized and debated because of their unwieldy and rumbling presence in a delicate historical setting. Lately, the construction of a tunnel to replace them has been suggested.

Background

Since the first decade of the 20th century, numerous proposals labelled "Centralbron" had been produced and more than 20 of them scrapped before the elaboration of the general plan of 1928. During the 1930s the need for a "central bridge" crossing Gamla stan, the old city, declined due to the realization of the plans for a western traffic route, Västerbron, and the clover-shaped traffic junction at Slussen, both finally inaugurated in 1935.

In 1930 plans for a Centralbron was therefore substituted by a temporary solution, by its customers dubbed Slingerbultsleden ("The Dodge Route"), criss-crossing the western streets of Gamla stan using two temporary bridges crossing Riddarholmskanalen to open out on Vasabron. While the metro system and Centralbron were being constructed Slingerbultsleden had to be scrapped, and in 1953 it was substituted by a 240 metres long pontoon bridge connecting the northern end of the now non-existent Riddarholmskajen ("Quay of Riddarholmen") to Klara strand. Its 7 metres wide roadway had a maximum capacity of 20,000 cars per day and remained in use until the completion of the northern bridge in 1967.

The southern bridge

The southern bridge leading from Gamla stan and Riddarholmen over to Södermalm.

WW2 further delayed any attempts to elaborate a permanent solution, but in 1947 a decision to build a southern bridge crossing Söderström was taken, and work finally begun in 1950. The 189 metres long and 21,3 metres wide bridge stretches over six spans with a maximum span of 33,7 metres. The continuous steel girders of the roadway are resting on concrete pillars firmly anchored to the soil by numerous poles.

To the south, another two spans are stretching some 46 metres over Söder Mälarstrand ("Southern Shore of Lake Mälaren") before three smaller spans hands the roadway over to Söderledstunneln ("The Southern Route Tunnel"). To the north, the bridge is continuous with a 173 metres long viaduct passing over the Gamla stan metro station. The viaduct is made of a concrete roadway resting on steel girders.

The entire structure was completed and inaugurated June 16th 1959, the name 'Centralbron' now being official by a naming committee assuming that a Österbron ("The Eastern Bridge") would be built, making Centralbron a truly central bridge. An eastern route is as of 2007 not a timely topic, for several reasons but particularly because of Ekoparken ("The Eco Park") taking up most of the area east of the city, thus making such a route infeasible.

The northern bridge

The islet Strömsborg with Centralbron passing in front and Vasabron behind.

The realization of the northern bridge stretching over Norrström had to be postponed until the enlargement of the traffic junction at Tegelbacken was resolved in 1961. The bridge, finally inaugurated September 3rd 1967, is a 246 metres long and 22,3 metres wide reinforced concrete structure with an average span of 19 meters. To the north, it makes a sharp turn to the west where it extends over the railway to Klarastrandsleden.

See also

• List of bridges in Stockholm
• Riddarholmsbron
• Vasabron